test_categorical.py

# -*- coding: utf-8 -*-
# pylint: disable=E1101,E1103,W0232

import os
import sys
from datetime import datetime
from distutils.version import LooseVersion

import numpy as np

from pandas.types.dtypes import CategoricalDtype
from pandas.types.common import (is_categorical_dtype,
                                 is_object_dtype,
                                 is_float_dtype,
                                 is_integer_dtype)

import pandas as pd
import pandas.compat as compat
import pandas.util.testing as tm
from pandas import (Categorical, Index, Series, DataFrame, PeriodIndex,
                    Timestamp, CategoricalIndex, isnull)
from pandas.compat import range, lrange, u, PY3
from pandas.core.config import option_context

# GH 12066
# flake8: noqa


class TestCategorical(tm.TestCase):
    _multiprocess_can_split_ = True

    def setUp(self):
        self.factor = Categorical.from_array(['a', 'b', 'b', 'a',
                                              'a', 'c', 'c', 'c'],
                                             ordered=True)

    def test_getitem(self):
        self.assertEqual(self.factor[0], 'a')
        self.assertEqual(self.factor[-1], 'c')

        subf = self.factor[[0, 1, 2]]
        tm.assert_numpy_array_equal(subf._codes,
                                    np.array([0, 1, 1], dtype=np.int8))

        subf = self.factor[np.asarray(self.factor) == 'c']
        tm.assert_numpy_array_equal(subf._codes,
                                    np.array([2, 2, 2], dtype=np.int8))

    def test_getitem_listlike(self):

        # GH 9469
        # properly coerce the input indexers
        np.random.seed(1)
        c = Categorical(np.random.randint(0, 5, size=150000).astype(np.int8))
        result = c.codes[np.array([100000]).astype(np.int64)]
        expected = c[np.array([100000]).astype(np.int64)].codes
        self.assert_numpy_array_equal(result, expected)

    def test_setitem(self):

        # int/positional
        c = self.factor.copy()
        c[0] = 'b'
        self.assertEqual(c[0], 'b')
        c[-1] = 'a'
        self.assertEqual(c[-1], 'a')

        # boolean
        c = self.factor.copy()
        indexer = np.zeros(len(c), dtype='bool')
        indexer[0] = True
        indexer[-1] = True
        c[indexer] = 'c'
        expected = Categorical.from_array(['c', 'b', 'b', 'a',
                                           'a', 'c', 'c', 'c'], ordered=True)

        self.assert_categorical_equal(c, expected)

    def test_setitem_listlike(self):

        # GH 9469
        # properly coerce the input indexers
        np.random.seed(1)
        c = Categorical(np.random.randint(0, 5, size=150000).astype(
            np.int8)).add_categories([-1000])
        indexer = np.array([100000]).astype(np.int64)
        c[indexer] = -1000

        # we are asserting the code result here
        # which maps to the -1000 category
        result = c.codes[np.array([100000]).astype(np.int64)]
        self.assertEqual(result, np.array([5], dtype='int8'))

    def test_constructor_unsortable(self):

        # it works!
        arr = np.array([1, 2, 3, datetime.now()], dtype='O')
        factor = Categorical.from_array(arr, ordered=False)
        self.assertFalse(factor.ordered)

        if compat.PY3:
            self.assertRaises(
                TypeError, lambda: Categorical.from_array(arr, ordered=True))
        else:
            # this however will raise as cannot be sorted (on PY3 or older
            # numpies)
            if LooseVersion(np.__version__) < "1.10":
                self.assertRaises(
                    TypeError,
                    lambda: Categorical.from_array(arr, ordered=True))
            else:
                Categorical.from_array(arr, ordered=True)

    def test_is_equal_dtype(self):

        # test dtype comparisons between cats

        c1 = Categorical(list('aabca'), categories=list('abc'), ordered=False)
        c2 = Categorical(list('aabca'), categories=list('cab'), ordered=False)
        c3 = Categorical(list('aabca'), categories=list('cab'), ordered=True)
        self.assertTrue(c1.is_dtype_equal(c1))
        self.assertTrue(c2.is_dtype_equal(c2))
        self.assertTrue(c3.is_dtype_equal(c3))
        self.assertFalse(c1.is_dtype_equal(c2))
        self.assertFalse(c1.is_dtype_equal(c3))
        self.assertFalse(c1.is_dtype_equal(Index(list('aabca'))))
        self.assertFalse(c1.is_dtype_equal(c1.astype(object)))
        self.assertTrue(c1.is_dtype_equal(CategoricalIndex(c1)))
        self.assertFalse(c1.is_dtype_equal(
            CategoricalIndex(c1, categories=list('cab'))))
        self.assertFalse(c1.is_dtype_equal(CategoricalIndex(c1, ordered=True)))

    def test_constructor(self):

        exp_arr = np.array(["a", "b", "c", "a", "b", "c"], dtype=np.object_)
        c1 = Categorical(exp_arr)
        self.assert_numpy_array_equal(c1.__array__(), exp_arr)
        c2 = Categorical(exp_arr, categories=["a", "b", "c"])
        self.assert_numpy_array_equal(c2.__array__(), exp_arr)
        c2 = Categorical(exp_arr, categories=["c", "b", "a"])
        self.assert_numpy_array_equal(c2.__array__(), exp_arr)

        # categories must be unique
        def f():
            Categorical([1, 2], [1, 2, 2])

        self.assertRaises(ValueError, f)

        def f():
            Categorical(["a", "b"], ["a", "b", "b"])

        self.assertRaises(ValueError, f)

        def f():
            with tm.assert_produces_warning(FutureWarning):
                Categorical([1, 2], [1, 2, np.nan, np.nan])

        self.assertRaises(ValueError, f)

        # The default should be unordered
        c1 = Categorical(["a", "b", "c", "a"])
        self.assertFalse(c1.ordered)

        # Categorical as input
        c1 = Categorical(["a", "b", "c", "a"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(c1, categories=["a", "b", "c"])
        self.assert_numpy_array_equal(c1.__array__(), c2.__array__())
        self.assert_index_equal(c2.categories, Index(["a", "b", "c"]))

        # Series of dtype category
        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(Series(c1))
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(Series(c1))
        tm.assert_categorical_equal(c1, c2)

        # Series
        c1 = Categorical(["a", "b", "c", "a"])
        c2 = Categorical(Series(["a", "b", "c", "a"]))
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(Series(["a", "b", "c", "a"]),
                         categories=["a", "b", "c", "d"])
        tm.assert_categorical_equal(c1, c2)

        # This should result in integer categories, not float!
        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        self.assertTrue(is_integer_dtype(cat.categories))

        # https://github.com/pydata/pandas/issues/3678
        cat = pd.Categorical([np.nan, 1, 2, 3])
        self.assertTrue(is_integer_dtype(cat.categories))

        # this should result in floats
        cat = pd.Categorical([np.nan, 1, 2., 3])
        self.assertTrue(is_float_dtype(cat.categories))

        cat = pd.Categorical([np.nan, 1., 2., 3.])
        self.assertTrue(is_float_dtype(cat.categories))

        # Deprecating NaNs in categoires (GH #10748)
        # preserve int as far as possible by converting to object if NaN is in
        # categories
        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical([np.nan, 1, 2, 3],
                                 categories=[np.nan, 1, 2, 3])
        self.assertTrue(is_object_dtype(cat.categories))

        # This doesn't work -> this would probably need some kind of "remember
        # the original type" feature to try to cast the array interface result
        # to...

        # vals = np.asarray(cat[cat.notnull()])
        # self.assertTrue(is_integer_dtype(vals))
        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical([np.nan, "a", "b", "c"],
                                 categories=[np.nan, "a", "b", "c"])
        self.assertTrue(is_object_dtype(cat.categories))
        # but don't do it for floats
        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical([np.nan, 1., 2., 3.],
                                 categories=[np.nan, 1., 2., 3.])
        self.assertTrue(is_float_dtype(cat.categories))

        # corner cases
        cat = pd.Categorical([1])
        self.assertTrue(len(cat.categories) == 1)
        self.assertTrue(cat.categories[0] == 1)
        self.assertTrue(len(cat.codes) == 1)
        self.assertTrue(cat.codes[0] == 0)

        cat = pd.Categorical(["a"])
        self.assertTrue(len(cat.categories) == 1)
        self.assertTrue(cat.categories[0] == "a")
        self.assertTrue(len(cat.codes) == 1)
        self.assertTrue(cat.codes[0] == 0)

        # Scalars should be converted to lists
        cat = pd.Categorical(1)
        self.assertTrue(len(cat.categories) == 1)
        self.assertTrue(cat.categories[0] == 1)
        self.assertTrue(len(cat.codes) == 1)
        self.assertTrue(cat.codes[0] == 0)

        cat = pd.Categorical([1], categories=1)
        self.assertTrue(len(cat.categories) == 1)
        self.assertTrue(cat.categories[0] == 1)
        self.assertTrue(len(cat.codes) == 1)
        self.assertTrue(cat.codes[0] == 0)

        # Catch old style constructor useage: two arrays, codes + categories
        # We can only catch two cases:
        #  - when the first is an integer dtype and the second is not
        #  - when the resulting codes are all -1/NaN
        with tm.assert_produces_warning(RuntimeWarning):
            c_old = Categorical([0, 1, 2, 0, 1, 2],
                                categories=["a", "b", "c"])  # noqa

        with tm.assert_produces_warning(RuntimeWarning):
            c_old = Categorical([0, 1, 2, 0, 1, 2],  # noqa
                                categories=[3, 4, 5])

        # the next one are from the old docs, but unfortunately these don't
        # trigger :-(
        with tm.assert_produces_warning(None):
            c_old2 = Categorical([0, 1, 2, 0, 1, 2], [1, 2, 3])  # noqa
            cat = Categorical([1, 2], categories=[1, 2, 3])

        # this is a legitimate constructor
        with tm.assert_produces_warning(None):
            c = Categorical(np.array([], dtype='int64'),  # noqa
                            categories=[3, 2, 1], ordered=True)

    def test_constructor_with_index(self):
        ci = CategoricalIndex(list('aabbca'), categories=list('cab'))
        tm.assert_categorical_equal(ci.values, Categorical(ci))

        ci = CategoricalIndex(list('aabbca'), categories=list('cab'))
        tm.assert_categorical_equal(ci.values,
                                    Categorical(ci.astype(object),
                                                categories=ci.categories))

    def test_constructor_with_generator(self):
        # This was raising an Error in isnull(single_val).any() because isnull
        # returned a scalar for a generator
        xrange = range

        exp = Categorical([0, 1, 2])
        cat = Categorical((x for x in [0, 1, 2]))
        tm.assert_categorical_equal(cat, exp)
        cat = Categorical(xrange(3))
        tm.assert_categorical_equal(cat, exp)

        # This uses xrange internally
        from pandas.core.index import MultiIndex
        MultiIndex.from_product([range(5), ['a', 'b', 'c']])

        # check that categories accept generators and sequences
        cat = pd.Categorical([0, 1, 2], categories=(x for x in [0, 1, 2]))
        tm.assert_categorical_equal(cat, exp)
        cat = pd.Categorical([0, 1, 2], categories=xrange(3))
        tm.assert_categorical_equal(cat, exp)

    def test_constructor_with_datetimelike(self):

        # 12077
        # constructor wwth a datetimelike and NaT

        for dtl in [pd.date_range('1995-01-01 00:00:00',
                                  periods=5, freq='s'),
                    pd.date_range('1995-01-01 00:00:00',
                                  periods=5, freq='s', tz='US/Eastern'),
                    pd.timedelta_range('1 day', periods=5, freq='s')]:

            s = Series(dtl)
            c = Categorical(s)
            expected = type(dtl)(s)
            expected.freq = None
            tm.assert_index_equal(c.categories, expected)
            self.assert_numpy_array_equal(c.codes, np.arange(5, dtype='int8'))

            # with NaT
            s2 = s.copy()
            s2.iloc[-1] = pd.NaT
            c = Categorical(s2)
            expected = type(dtl)(s2.dropna())
            expected.freq = None
            tm.assert_index_equal(c.categories, expected)

            exp = np.array([0, 1, 2, 3, -1], dtype=np.int8)
            self.assert_numpy_array_equal(c.codes, exp)

            result = repr(c)
            self.assertTrue('NaT' in result)

    def test_constructor_from_index_series_datetimetz(self):
        idx = pd.date_range('2015-01-01 10:00', freq='D', periods=3,
                            tz='US/Eastern')
        result = pd.Categorical.from_array(idx)
        tm.assert_index_equal(result.categories, idx)

        result = pd.Categorical.from_array(pd.Series(idx))
        tm.assert_index_equal(result.categories, idx)

    def test_constructor_from_index_series_timedelta(self):
        idx = pd.timedelta_range('1 days', freq='D', periods=3)
        result = pd.Categorical.from_array(idx)
        tm.assert_index_equal(result.categories, idx)

        result = pd.Categorical.from_array(pd.Series(idx))
        tm.assert_index_equal(result.categories, idx)

    def test_constructor_from_index_series_period(self):
        idx = pd.period_range('2015-01-01', freq='D', periods=3)
        result = pd.Categorical.from_array(idx)
        tm.assert_index_equal(result.categories, idx)

        result = pd.Categorical.from_array(pd.Series(idx))
        tm.assert_index_equal(result.categories, idx)

    def test_from_codes(self):

        # too few categories
        def f():
            Categorical.from_codes([1, 2], [1, 2])

        self.assertRaises(ValueError, f)

        # no int codes
        def f():
            Categorical.from_codes(["a"], [1, 2])

        self.assertRaises(ValueError, f)

        # no unique categories
        def f():
            Categorical.from_codes([0, 1, 2], ["a", "a", "b"])

        self.assertRaises(ValueError, f)

        # too negative
        def f():
            Categorical.from_codes([-2, 1, 2], ["a", "b", "c"])

        self.assertRaises(ValueError, f)

        exp = Categorical(["a", "b", "c"], ordered=False)
        res = Categorical.from_codes([0, 1, 2], ["a", "b", "c"])
        tm.assert_categorical_equal(exp, res)

        # Not available in earlier numpy versions
        if hasattr(np.random, "choice"):
            codes = np.random.choice([0, 1], 5, p=[0.9, 0.1])
            pd.Categorical.from_codes(codes, categories=["train", "test"])

    def test_comparisons(self):

        result = self.factor[self.factor == 'a']
        expected = self.factor[np.asarray(self.factor) == 'a']
        tm.assert_categorical_equal(result, expected)

        result = self.factor[self.factor != 'a']
        expected = self.factor[np.asarray(self.factor) != 'a']
        tm.assert_categorical_equal(result, expected)

        result = self.factor[self.factor < 'c']
        expected = self.factor[np.asarray(self.factor) < 'c']
        tm.assert_categorical_equal(result, expected)

        result = self.factor[self.factor > 'a']
        expected = self.factor[np.asarray(self.factor) > 'a']
        tm.assert_categorical_equal(result, expected)

        result = self.factor[self.factor >= 'b']
        expected = self.factor[np.asarray(self.factor) >= 'b']
        tm.assert_categorical_equal(result, expected)

        result = self.factor[self.factor <= 'b']
        expected = self.factor[np.asarray(self.factor) <= 'b']
        tm.assert_categorical_equal(result, expected)

        n = len(self.factor)

        other = self.factor[np.random.permutation(n)]
        result = self.factor == other
        expected = np.asarray(self.factor) == np.asarray(other)
        self.assert_numpy_array_equal(result, expected)

        result = self.factor == 'd'
        expected = np.repeat(False, len(self.factor))
        self.assert_numpy_array_equal(result, expected)

        # comparisons with categoricals
        cat_rev = pd.Categorical(["a", "b", "c"], categories=["c", "b", "a"],
                                 ordered=True)
        cat_rev_base = pd.Categorical(
            ["b", "b", "b"], categories=["c", "b", "a"], ordered=True)
        cat = pd.Categorical(["a", "b", "c"], ordered=True)
        cat_base = pd.Categorical(["b", "b", "b"], categories=cat.categories,
                                  ordered=True)

        # comparisons need to take categories ordering into account
        res_rev = cat_rev > cat_rev_base
        exp_rev = np.array([True, False, False])
        self.assert_numpy_array_equal(res_rev, exp_rev)

        res_rev = cat_rev < cat_rev_base
        exp_rev = np.array([False, False, True])
        self.assert_numpy_array_equal(res_rev, exp_rev)

        res = cat > cat_base
        exp = np.array([False, False, True])
        self.assert_numpy_array_equal(res, exp)

        # Only categories with same categories can be compared
        def f():
            cat > cat_rev

        self.assertRaises(TypeError, f)

        cat_rev_base2 = pd.Categorical(
            ["b", "b", "b"], categories=["c", "b", "a", "d"])

        def f():
            cat_rev > cat_rev_base2

        self.assertRaises(TypeError, f)

        # Only categories with same ordering information can be compared
        cat_unorderd = cat.set_ordered(False)
        self.assertFalse((cat > cat).any())

        def f():
            cat > cat_unorderd

        self.assertRaises(TypeError, f)

        # comparison (in both directions) with Series will raise
        s = Series(["b", "b", "b"])
        self.assertRaises(TypeError, lambda: cat > s)
        self.assertRaises(TypeError, lambda: cat_rev > s)
        self.assertRaises(TypeError, lambda: s < cat)
        self.assertRaises(TypeError, lambda: s < cat_rev)

        # comparison with numpy.array will raise in both direction, but only on
        # newer numpy versions
        a = np.array(["b", "b", "b"])
        self.assertRaises(TypeError, lambda: cat > a)
        self.assertRaises(TypeError, lambda: cat_rev > a)

        # The following work via '__array_priority__ = 1000'
        # works only on numpy >= 1.7.1
        if LooseVersion(np.__version__) > "1.7.1":
            self.assertRaises(TypeError, lambda: a < cat)
            self.assertRaises(TypeError, lambda: a < cat_rev)

        # Make sure that unequal comparison take the categories order in
        # account
        cat_rev = pd.Categorical(
            list("abc"), categories=list("cba"), ordered=True)
        exp = np.array([True, False, False])
        res = cat_rev > "b"
        self.assert_numpy_array_equal(res, exp)

    def test_argsort(self):
        c = Categorical([5, 3, 1, 4, 2], ordered=True)

        expected = np.array([2, 4, 1, 3, 0])
        tm.assert_numpy_array_equal(c.argsort(ascending=True), expected,
                                    check_dtype=False)

        expected = expected[::-1]
        tm.assert_numpy_array_equal(c.argsort(ascending=False), expected,
                                    check_dtype=False)

    def test_numpy_argsort(self):
        c = Categorical([5, 3, 1, 4, 2], ordered=True)

        expected = np.array([2, 4, 1, 3, 0])
        tm.assert_numpy_array_equal(np.argsort(c), expected,
                                    check_dtype=False)

        msg = "the 'kind' parameter is not supported"
        tm.assertRaisesRegexp(ValueError, msg, np.argsort,
                              c, kind='mergesort')

        msg = "the 'axis' parameter is not supported"
        tm.assertRaisesRegexp(ValueError, msg, np.argsort,
                              c, axis=0)

        msg = "the 'order' parameter is not supported"
        tm.assertRaisesRegexp(ValueError, msg, np.argsort,
                              c, order='C')

    def test_na_flags_int_categories(self):
        # #1457

        categories = lrange(10)
        labels = np.random.randint(0, 10, 20)
        labels[::5] = -1

        cat = Categorical(labels, categories, fastpath=True)
        repr(cat)

        self.assert_numpy_array_equal(isnull(cat), labels == -1)

    def test_categories_none(self):
        factor = Categorical(['a', 'b', 'b', 'a',
                              'a', 'c', 'c', 'c'], ordered=True)
        tm.assert_categorical_equal(factor, self.factor)

    def test_describe(self):
        # string type
        desc = self.factor.describe()
        self.assertTrue(self.factor.ordered)
        exp_index = pd.CategoricalIndex(['a', 'b', 'c'], name='categories',
                                        ordered=self.factor.ordered)
        expected = DataFrame({'counts': [3, 2, 3],
                              'freqs': [3 / 8., 2 / 8., 3 / 8.]},
                             index=exp_index)
        tm.assert_frame_equal(desc, expected)

        # check unused categories
        cat = self.factor.copy()
        cat.set_categories(["a", "b", "c", "d"], inplace=True)
        desc = cat.describe()

        exp_index = pd.CategoricalIndex(['a', 'b', 'c', 'd'],
                                        ordered=self.factor.ordered,
                                        name='categories')
        expected = DataFrame({'counts': [3, 2, 3, 0],
                              'freqs': [3 / 8., 2 / 8., 3 / 8., 0]},
                             index=exp_index)
        tm.assert_frame_equal(desc, expected)

        # check an integer one
        cat = Categorical([1, 2, 3, 1, 2, 3, 3, 2, 1, 1, 1])
        desc = cat.describe()
        exp_index = pd.CategoricalIndex([1, 2, 3], ordered=cat.ordered,
                                        name='categories')
        expected = DataFrame({'counts': [5, 3, 3],
                              'freqs': [5 / 11., 3 / 11., 3 / 11.]},
                             index=exp_index)
        tm.assert_frame_equal(desc, expected)

        # https://github.com/pydata/pandas/issues/3678
        # describe should work with NaN
        cat = pd.Categorical([np.nan, 1, 2, 2])
        desc = cat.describe()
        expected = DataFrame({'counts': [1, 2, 1],
                              'freqs': [1 / 4., 2 / 4., 1 / 4.]},
                             index=pd.CategoricalIndex([1, 2, np.nan],
                                                       categories=[1, 2],
                                                       name='categories'))
        tm.assert_frame_equal(desc, expected)

        # NA as a category
        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical(["a", "c", "c", np.nan],
                                 categories=["b", "a", "c", np.nan])
            result = cat.describe()

        expected = DataFrame([[0, 0], [1, 0.25], [2, 0.5], [1, 0.25]],
                             columns=['counts', 'freqs'],
                             index=pd.CategoricalIndex(['b', 'a', 'c', np.nan],
                                                       name='categories'))
        tm.assert_frame_equal(result, expected, check_categorical=False)

        # NA as an unused category
        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical(["a", "c", "c"],
                                 categories=["b", "a", "c", np.nan])
            result = cat.describe()

        exp_idx = pd.CategoricalIndex(
            ['b', 'a', 'c', np.nan], name='categories')
        expected = DataFrame([[0, 0], [1, 1 / 3.], [2, 2 / 3.], [0, 0]],
                             columns=['counts', 'freqs'], index=exp_idx)
        tm.assert_frame_equal(result, expected, check_categorical=False)

    def test_print(self):
        expected = ["[a, b, b, a, a, c, c, c]",
                    "Categories (3, object): [a < b < c]"]
        expected = "\n".join(expected)
        actual = repr(self.factor)
        self.assertEqual(actual, expected)

    def test_big_print(self):
        factor = Categorical([0, 1, 2, 0, 1, 2] * 100, ['a', 'b', 'c'],
                             name='cat', fastpath=True)
        expected = ["[a, b, c, a, b, ..., b, c, a, b, c]", "Length: 600",
                    "Categories (3, object): [a, b, c]"]
        expected = "\n".join(expected)

        actual = repr(factor)

        self.assertEqual(actual, expected)

    def test_empty_print(self):
        factor = Categorical([], ["a", "b", "c"])
        expected = ("[], Categories (3, object): [a, b, c]")
        # hack because array_repr changed in numpy > 1.6.x
        actual = repr(factor)
        self.assertEqual(actual, expected)

        self.assertEqual(expected, actual)
        factor = Categorical([], ["a", "b", "c"], ordered=True)
        expected = ("[], Categories (3, object): [a < b < c]")
        actual = repr(factor)
        self.assertEqual(expected, actual)

        factor = Categorical([], [])
        expected = ("[], Categories (0, object): []")
        self.assertEqual(expected, repr(factor))

    def test_print_none_width(self):
        # GH10087
        a = pd.Series(pd.Categorical([1, 2, 3, 4]))
        exp = u("0    1\n1    2\n2    3\n3    4\n" +
                "dtype: category\nCategories (4, int64): [1, 2, 3, 4]")

        with option_context("display.width", None):
            self.assertEqual(exp, repr(a))

    def test_unicode_print(self):
        if PY3:
            _rep = repr
        else:
            _rep = unicode  # noqa

        c = pd.Categorical(['aaaaa', 'bb', 'cccc'] * 20)
        expected = u"""\
[aaaaa, bb, cccc, aaaaa, bb, ..., bb, cccc, aaaaa, bb, cccc]
Length: 60
Categories (3, object): [aaaaa, bb, cccc]"""

        self.assertEqual(_rep(c), expected)

        c = pd.Categorical([u'ああああ', u'いいいいい', u'ううううううう']
                           * 20)
        expected = u"""\
[ああああ, いいいいい, ううううううう, ああああ, いいいいい, ..., いいいいい, ううううううう, ああああ, いいいいい, ううううううう]
Length: 60
Categories (3, object): [ああああ, いいいいい, ううううううう]"""  # noqa

        self.assertEqual(_rep(c), expected)

        # unicode option should not affect to Categorical, as it doesn't care
        # the repr width
        with option_context('display.unicode.east_asian_width', True):

            c = pd.Categorical([u'ああああ', u'いいいいい', u'ううううううう']
                               * 20)
            expected = u"""[ああああ, いいいいい, ううううううう, ああああ, いいいいい, ..., いいいいい, ううううううう, ああああ, いいいいい, ううううううう]
Length: 60
Categories (3, object): [ああああ, いいいいい, ううううううう]"""  # noqa

            self.assertEqual(_rep(c), expected)

    def test_periodindex(self):
        idx1 = PeriodIndex(['2014-01', '2014-01', '2014-02', '2014-02',
                            '2014-03', '2014-03'], freq='M')

        cat1 = Categorical.from_array(idx1)
        str(cat1)
        exp_arr = np.array([0, 0, 1, 1, 2, 2], dtype=np.int8)
        exp_idx = PeriodIndex(['2014-01', '2014-02', '2014-03'], freq='M')
        self.assert_numpy_array_equal(cat1._codes, exp_arr)
        self.assert_index_equal(cat1.categories, exp_idx)

        idx2 = PeriodIndex(['2014-03', '2014-03', '2014-02', '2014-01',
                            '2014-03', '2014-01'], freq='M')
        cat2 = Categorical.from_array(idx2, ordered=True)
        str(cat2)
        exp_arr = np.array([2, 2, 1, 0, 2, 0], dtype=np.int8)
        exp_idx2 = PeriodIndex(['2014-01', '2014-02', '2014-03'], freq='M')
        self.assert_numpy_array_equal(cat2._codes, exp_arr)
        self.assert_index_equal(cat2.categories, exp_idx2)

        idx3 = PeriodIndex(['2013-12', '2013-11', '2013-10', '2013-09',
                            '2013-08', '2013-07', '2013-05'], freq='M')
        cat3 = Categorical.from_array(idx3, ordered=True)
        exp_arr = np.array([6, 5, 4, 3, 2, 1, 0], dtype=np.int8)
        exp_idx = PeriodIndex(['2013-05', '2013-07', '2013-08', '2013-09',
                               '2013-10', '2013-11', '2013-12'], freq='M')
        self.assert_numpy_array_equal(cat3._codes, exp_arr)
        self.assert_index_equal(cat3.categories, exp_idx)

    def test_categories_assigments(self):
        s = pd.Categorical(["a", "b", "c", "a"])
        exp = np.array([1, 2, 3, 1], dtype=np.int64)
        s.categories = [1, 2, 3]
        self.assert_numpy_array_equal(s.__array__(), exp)
        self.assert_index_equal(s.categories, Index([1, 2, 3]))

        # lengthen
        def f():
            s.categories = [1, 2, 3, 4]

        self.assertRaises(ValueError, f)

        # shorten
        def f():
            s.categories = [1, 2]

        self.assertRaises(ValueError, f)

    def test_construction_with_ordered(self):
        # GH 9347, 9190
        cat = Categorical([0, 1, 2])
        self.assertFalse(cat.ordered)
        cat = Categorical([0, 1, 2], ordered=False)
        self.assertFalse(cat.ordered)
        cat = Categorical([0, 1, 2], ordered=True)
        self.assertTrue(cat.ordered)

    def test_ordered_api(self):
        # GH 9347
        cat1 = pd.Categorical(["a", "c", "b"], ordered=False)
        self.assert_index_equal(cat1.categories, Index(['a', 'b', 'c']))
        self.assertFalse(cat1.ordered)

        cat2 = pd.Categorical(["a", "c", "b"], categories=['b', 'c', 'a'],
                              ordered=False)
        self.assert_index_equal(cat2.categories, Index(['b', 'c', 'a']))
        self.assertFalse(cat2.ordered)

        cat3 = pd.Categorical(["a", "c", "b"], ordered=True)
        self.assert_index_equal(cat3.categories, Index(['a', 'b', 'c']))
        self.assertTrue(cat3.ordered)

        cat4 = pd.Categorical(["a", "c", "b"], categories=['b', 'c', 'a'],
                              ordered=True)
        self.assert_index_equal(cat4.categories, Index(['b', 'c', 'a']))
        self.assertTrue(cat4.ordered)

    def test_set_ordered(self):

        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        cat2 = cat.as_unordered()
        self.assertFalse(cat2.ordered)
        cat2 = cat.as_ordered()
        self.assertTrue(cat2.ordered)
        cat2.as_unordered(inplace=True)
        self.assertFalse(cat2.ordered)
        cat2.as_ordered(inplace=True)
        self.assertTrue(cat2.ordered)

        self.assertTrue(cat2.set_ordered(True).ordered)
        self.assertFalse(cat2.set_ordered(False).ordered)
        cat2.set_ordered(True, inplace=True)
        self.assertTrue(cat2.ordered)
        cat2.set_ordered(False, inplace=True)
        self.assertFalse(cat2.ordered)

        # deperecated in v0.16.0
        with tm.assert_produces_warning(FutureWarning):
            cat.ordered = False
            self.assertFalse(cat.ordered)
        with tm.assert_produces_warning(FutureWarning):
            cat.ordered = True
            self.assertTrue(cat.ordered)

    def test_set_categories(self):
        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        exp_categories = Index(["c", "b", "a"])
        exp_values = np.array(["a", "b", "c", "a"], dtype=np.object_)

        res = cat.set_categories(["c", "b", "a"], inplace=True)
        self.assert_index_equal(cat.categories, exp_categories)
        self.assert_numpy_array_equal(cat.__array__(), exp_values)
        self.assertIsNone(res)

        res = cat.set_categories(["a", "b", "c"])
        # cat must be the same as before
        self.assert_index_equal(cat.categories, exp_categories)
        self.assert_numpy_array_equal(cat.__array__(), exp_values)
        # only res is changed
        exp_categories_back = Index(["a", "b", "c"])
        self.assert_index_equal(res.categories, exp_categories_back)
        self.assert_numpy_array_equal(res.__array__(), exp_values)

        # not all "old" included in "new" -> all not included ones are now
        # np.nan
        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        res = cat.set_categories(["a"])
        self.assert_numpy_array_equal(res.codes,
                                      np.array([0, -1, -1, 0], dtype=np.int8))

        # still not all "old" in "new"
        res = cat.set_categories(["a", "b", "d"])
        self.assert_numpy_array_equal(res.codes,
                                      np.array([0, 1, -1, 0], dtype=np.int8))
        self.assert_index_equal(res.categories, Index(["a", "b", "d"]))

        # all "old" included in "new"
        cat = cat.set_categories(["a", "b", "c", "d"])
        exp_categories = Index(["a", "b", "c", "d"])
        self.assert_index_equal(cat.categories, exp_categories)

        # internals...
        c = Categorical([1, 2, 3, 4, 1], categories=[1, 2, 3, 4], ordered=True)
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, 2, 3, 0], dtype=np.int8))
        self.assert_index_equal(c.categories, Index([1, 2, 3, 4]))

        exp = np.array([1, 2, 3, 4, 1], dtype=np.int64)
        self.assert_numpy_array_equal(c.get_values(), exp)

        # all "pointers" to '4' must be changed from 3 to 0,...
        c = c.set_categories([4, 3, 2, 1])

        # positions are changed
        self.assert_numpy_array_equal(c._codes,
                                      np.array([3, 2, 1, 0, 3], dtype=np.int8))

        # categories are now in new order
        self.assert_index_equal(c.categories, Index([4, 3, 2, 1]))

        # output is the same
        exp = np.array([1, 2, 3, 4, 1], dtype=np.int64)
        self.assert_numpy_array_equal(c.get_values(), exp)
        self.assertTrue(c.min(), 4)
        self.assertTrue(c.max(), 1)

        # set_categories should set the ordering if specified
        c2 = c.set_categories([4, 3, 2, 1], ordered=False)
        self.assertFalse(c2.ordered)
        self.assert_numpy_array_equal(c.get_values(), c2.get_values())

        # set_categories should pass thru the ordering
        c2 = c.set_ordered(False).set_categories([4, 3, 2, 1])
        self.assertFalse(c2.ordered)
        self.assert_numpy_array_equal(c.get_values(), c2.get_values())

    def test_rename_categories(self):
        cat = pd.Categorical(["a", "b", "c", "a"])

        # inplace=False: the old one must not be changed
        res = cat.rename_categories([1, 2, 3])
        self.assert_numpy_array_equal(res.__array__(),
                                      np.array([1, 2, 3, 1], dtype=np.int64))
        self.assert_index_equal(res.categories, Index([1, 2, 3]))

        exp_cat = np.array(["a", "b", "c", "a"], dtype=np.object_)
        self.assert_numpy_array_equal(cat.__array__(), exp_cat)

        exp_cat = Index(["a", "b", "c"])
        self.assert_index_equal(cat.categories, exp_cat)
        res = cat.rename_categories([1, 2, 3], inplace=True)

        # and now inplace
        self.assertIsNone(res)
        self.assert_numpy_array_equal(cat.__array__(),
                                      np.array([1, 2, 3, 1], dtype=np.int64))
        self.assert_index_equal(cat.categories, Index([1, 2, 3]))

        # lengthen
        def f():
            cat.rename_categories([1, 2, 3, 4])

        self.assertRaises(ValueError, f)

        # shorten
        def f():
            cat.rename_categories([1, 2])

        self.assertRaises(ValueError, f)

    def test_reorder_categories(self):
        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        old = cat.copy()
        new = Categorical(["a", "b", "c", "a"], categories=["c", "b", "a"],
                          ordered=True)

        # first inplace == False
        res = cat.reorder_categories(["c", "b", "a"])
        # cat must be the same as before
        self.assert_categorical_equal(cat, old)
        # only res is changed
        self.assert_categorical_equal(res, new)

        # inplace == True
        res = cat.reorder_categories(["c", "b", "a"], inplace=True)
        self.assertIsNone(res)
        self.assert_categorical_equal(cat, new)

        # not all "old" included in "new"
        cat = Categorical(["a", "b", "c", "a"], ordered=True)

        def f():
            cat.reorder_categories(["a"])

        self.assertRaises(ValueError, f)

        # still not all "old" in "new"
        def f():
            cat.reorder_categories(["a", "b", "d"])

        self.assertRaises(ValueError, f)

        # all "old" included in "new", but too long
        def f():
            cat.reorder_categories(["a", "b", "c", "d"])

        self.assertRaises(ValueError, f)

    def test_add_categories(self):
        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        old = cat.copy()
        new = Categorical(["a", "b", "c", "a"],
                          categories=["a", "b", "c", "d"], ordered=True)

        # first inplace == False
        res = cat.add_categories("d")
        self.assert_categorical_equal(cat, old)
        self.assert_categorical_equal(res, new)

        res = cat.add_categories(["d"])
        self.assert_categorical_equal(cat, old)
        self.assert_categorical_equal(res, new)

        # inplace == True
        res = cat.add_categories("d", inplace=True)
        self.assert_categorical_equal(cat, new)
        self.assertIsNone(res)

        # new is in old categories
        def f():
            cat.add_categories(["d"])

        self.assertRaises(ValueError, f)

        # GH 9927
        cat = Categorical(list("abc"), ordered=True)
        expected = Categorical(
            list("abc"), categories=list("abcde"), ordered=True)
        # test with Series, np.array, index, list
        res = cat.add_categories(Series(["d", "e"]))
        self.assert_categorical_equal(res, expected)
        res = cat.add_categories(np.array(["d", "e"]))
        self.assert_categorical_equal(res, expected)
        res = cat.add_categories(Index(["d", "e"]))
        self.assert_categorical_equal(res, expected)
        res = cat.add_categories(["d", "e"])
        self.assert_categorical_equal(res, expected)

    def test_remove_categories(self):
        cat = Categorical(["a", "b", "c", "a"], ordered=True)
        old = cat.copy()
        new = Categorical(["a", "b", np.nan, "a"], categories=["a", "b"],
                          ordered=True)

        # first inplace == False
        res = cat.remove_categories("c")
        self.assert_categorical_equal(cat, old)
        self.assert_categorical_equal(res, new)

        res = cat.remove_categories(["c"])
        self.assert_categorical_equal(cat, old)
        self.assert_categorical_equal(res, new)

        # inplace == True
        res = cat.remove_categories("c", inplace=True)
        self.assert_categorical_equal(cat, new)
        self.assertIsNone(res)

        # removal is not in categories
        def f():
            cat.remove_categories(["c"])

        self.assertRaises(ValueError, f)

    def test_remove_unused_categories(self):
        c = Categorical(["a", "b", "c", "d", "a"],
                        categories=["a", "b", "c", "d", "e"])
        exp_categories_all = Index(["a", "b", "c", "d", "e"])
        exp_categories_dropped = Index(["a", "b", "c", "d"])

        self.assert_index_equal(c.categories, exp_categories_all)

        res = c.remove_unused_categories()
        self.assert_index_equal(res.categories, exp_categories_dropped)
        self.assert_index_equal(c.categories, exp_categories_all)

        res = c.remove_unused_categories(inplace=True)
        self.assert_index_equal(c.categories, exp_categories_dropped)
        self.assertIsNone(res)

        # with NaN values (GH11599)
        c = Categorical(["a", "b", "c", np.nan],
                        categories=["a", "b", "c", "d", "e"])
        res = c.remove_unused_categories()
        self.assert_index_equal(res.categories,
                                Index(np.array(["a", "b", "c"])))
        exp_codes = np.array([0, 1, 2, -1], dtype=np.int8)
        self.assert_numpy_array_equal(res.codes, exp_codes)
        self.assert_index_equal(c.categories, exp_categories_all)

        val = ['F', np.nan, 'D', 'B', 'D', 'F', np.nan]
        cat = pd.Categorical(values=val, categories=list('ABCDEFG'))
        out = cat.remove_unused_categories()
        self.assert_index_equal(out.categories, Index(['B', 'D', 'F']))
        exp_codes = np.array([2, -1, 1, 0, 1, 2, -1], dtype=np.int8)
        self.assert_numpy_array_equal(out.codes, exp_codes)
        self.assertEqual(out.get_values().tolist(), val)

        alpha = list('abcdefghijklmnopqrstuvwxyz')
        val = np.random.choice(alpha[::2], 10000).astype('object')
        val[np.random.choice(len(val), 100)] = np.nan

        cat = pd.Categorical(values=val, categories=alpha)
        out = cat.remove_unused_categories()
        self.assertEqual(out.get_values().tolist(), val.tolist())

    def test_nan_handling(self):

        # Nans are represented as -1 in codes
        c = Categorical(["a", "b", np.nan, "a"])
        self.assert_index_equal(c.categories, Index(["a", "b"]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, -1, 0], dtype=np.int8))
        c[1] = np.nan
        self.assert_index_equal(c.categories, Index(["a", "b"]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, -1, -1, 0], dtype=np.int8))

        # If categories have nan included, the code should point to that
        # instead
        with tm.assert_produces_warning(FutureWarning):
            c = Categorical(["a", "b", np.nan, "a"],
                            categories=["a", "b", np.nan])
        self.assert_index_equal(c.categories, Index(["a", "b", np.nan]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, 2, 0], dtype=np.int8))
        c[1] = np.nan
        self.assert_index_equal(c.categories, Index(["a", "b", np.nan]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 2, 2, 0], dtype=np.int8))

        # Changing categories should also make the replaced category np.nan
        c = Categorical(["a", "b", "c", "a"])
        with tm.assert_produces_warning(FutureWarning):
            c.categories = ["a", "b", np.nan]  # noqa

        self.assert_index_equal(c.categories, Index(["a", "b", np.nan]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, 2, 0], dtype=np.int8))

        # Adding nan to categories should make assigned nan point to the
        # category!
        c = Categorical(["a", "b", np.nan, "a"])
        self.assert_index_equal(c.categories, Index(["a", "b"]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, -1, 0], dtype=np.int8))
        with tm.assert_produces_warning(FutureWarning):
            c.set_categories(["a", "b", np.nan], rename=True, inplace=True)

        self.assert_index_equal(c.categories, Index(["a", "b", np.nan]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 1, -1, 0], dtype=np.int8))
        c[1] = np.nan
        self.assert_index_equal(c.categories, Index(["a", "b", np.nan]))
        self.assert_numpy_array_equal(c._codes,
                                      np.array([0, 2, -1, 0], dtype=np.int8))

        # Remove null categories (GH 10156)
        cases = [([1.0, 2.0, np.nan], [1.0, 2.0]),
                 (['a', 'b', None], ['a', 'b']),
                 ([pd.Timestamp('2012-05-01'), pd.NaT],
                  [pd.Timestamp('2012-05-01')])]

        null_values = [np.nan, None, pd.NaT]

        for with_null, without in cases:
            with tm.assert_produces_warning(FutureWarning):
                base = Categorical([], with_null)
            expected = Categorical([], without)

            for nullval in null_values:
                result = base.remove_categories(nullval)
            self.assert_categorical_equal(result, expected)

        # Different null values are indistinguishable
        for i, j in [(0, 1), (0, 2), (1, 2)]:
            nulls = [null_values[i], null_values[j]]

            def f():
                with tm.assert_produces_warning(FutureWarning):
                    Categorical([], categories=nulls)

            self.assertRaises(ValueError, f)

    def test_isnull(self):
        exp = np.array([False, False, True])
        c = Categorical(["a", "b", np.nan])
        res = c.isnull()
        self.assert_numpy_array_equal(res, exp)

        with tm.assert_produces_warning(FutureWarning):
            c = Categorical(["a", "b", np.nan], categories=["a", "b", np.nan])
        res = c.isnull()
        self.assert_numpy_array_equal(res, exp)

        # test both nan in categories and as -1
        exp = np.array([True, False, True])
        c = Categorical(["a", "b", np.nan])
        with tm.assert_produces_warning(FutureWarning):
            c.set_categories(["a", "b", np.nan], rename=True, inplace=True)
        c[0] = np.nan
        res = c.isnull()
        self.assert_numpy_array_equal(res, exp)

    def test_codes_immutable(self):

        # Codes should be read only
        c = Categorical(["a", "b", "c", "a", np.nan])
        exp = np.array([0, 1, 2, 0, -1], dtype='int8')
        self.assert_numpy_array_equal(c.codes, exp)

        # Assignments to codes should raise
        def f():
            c.codes = np.array([0, 1, 2, 0, 1], dtype='int8')

        self.assertRaises(ValueError, f)

        # changes in the codes array should raise
        # np 1.6.1 raises RuntimeError rather than ValueError
        codes = c.codes

        def f():
            codes[4] = 1

        self.assertRaises(ValueError, f)

        # But even after getting the codes, the original array should still be
        # writeable!
        c[4] = "a"
        exp = np.array([0, 1, 2, 0, 0], dtype='int8')
        self.assert_numpy_array_equal(c.codes, exp)
        c._codes[4] = 2
        exp = np.array([0, 1, 2, 0, 2], dtype='int8')
        self.assert_numpy_array_equal(c.codes, exp)

    def test_min_max(self):

        # unordered cats have no min/max
        cat = Categorical(["a", "b", "c", "d"], ordered=False)
        self.assertRaises(TypeError, lambda: cat.min())
        self.assertRaises(TypeError, lambda: cat.max())
        cat = Categorical(["a", "b", "c", "d"], ordered=True)
        _min = cat.min()
        _max = cat.max()
        self.assertEqual(_min, "a")
        self.assertEqual(_max, "d")
        cat = Categorical(["a", "b", "c", "d"],
                          categories=['d', 'c', 'b', 'a'], ordered=True)
        _min = cat.min()
        _max = cat.max()
        self.assertEqual(_min, "d")
        self.assertEqual(_max, "a")
        cat = Categorical([np.nan, "b", "c", np.nan],
                          categories=['d', 'c', 'b', 'a'], ordered=True)
        _min = cat.min()
        _max = cat.max()
        self.assertTrue(np.isnan(_min))
        self.assertEqual(_max, "b")

        _min = cat.min(numeric_only=True)
        self.assertEqual(_min, "c")
        _max = cat.max(numeric_only=True)
        self.assertEqual(_max, "b")

        cat = Categorical([np.nan, 1, 2, np.nan], categories=[5, 4, 3, 2, 1],
                          ordered=True)
        _min = cat.min()
        _max = cat.max()
        self.assertTrue(np.isnan(_min))
        self.assertEqual(_max, 1)

        _min = cat.min(numeric_only=True)
        self.assertEqual(_min, 2)
        _max = cat.max(numeric_only=True)
        self.assertEqual(_max, 1)

    def test_unique(self):
        # categories are reordered based on value when ordered=False
        cat = Categorical(["a", "b"])
        exp = Index(["a", "b"])
        res = cat.unique()
        self.assert_index_equal(res.categories, exp)
        self.assert_categorical_equal(res, cat)

        cat = Categorical(["a", "b", "a", "a"], categories=["a", "b", "c"])
        res = cat.unique()
        self.assert_index_equal(res.categories, exp)
        tm.assert_categorical_equal(res, Categorical(exp))

        cat = Categorical(["c", "a", "b", "a", "a"],
                          categories=["a", "b", "c"])
        exp = Index(["c", "a", "b"])
        res = cat.unique()
        self.assert_index_equal(res.categories, exp)
        exp_cat = Categorical(exp, categories=['c', 'a', 'b'])
        tm.assert_categorical_equal(res, exp_cat)

        # nan must be removed
        cat = Categorical(["b", np.nan, "b", np.nan, "a"],
                          categories=["a", "b", "c"])
        res = cat.unique()
        exp = Index(["b", "a"])
        self.assert_index_equal(res.categories, exp)
        exp_cat = Categorical(["b", np.nan, "a"], categories=["b", "a"])
        tm.assert_categorical_equal(res, exp_cat)

    def test_unique_ordered(self):
        # keep categories order when ordered=True
        cat = Categorical(['b', 'a', 'b'], categories=['a', 'b'], ordered=True)
        res = cat.unique()
        exp_cat = Categorical(['b', 'a'], categories=['a', 'b'], ordered=True)
        tm.assert_categorical_equal(res, exp_cat)

        cat = Categorical(['c', 'b', 'a', 'a'], categories=['a', 'b', 'c'],
                          ordered=True)
        res = cat.unique()
        exp_cat = Categorical(['c', 'b', 'a'], categories=['a', 'b', 'c'],
                              ordered=True)
        tm.assert_categorical_equal(res, exp_cat)

        cat = Categorical(['b', 'a', 'a'], categories=['a', 'b', 'c'],
                          ordered=True)
        res = cat.unique()
        exp_cat = Categorical(['b', 'a'], categories=['a', 'b'], ordered=True)
        tm.assert_categorical_equal(res, exp_cat)

        cat = Categorical(['b', 'b', np.nan, 'a'], categories=['a', 'b', 'c'],
                          ordered=True)
        res = cat.unique()
        exp_cat = Categorical(['b', np.nan, 'a'], categories=['a', 'b'],
                              ordered=True)
        tm.assert_categorical_equal(res, exp_cat)

    def test_mode(self):
        s = Categorical([1, 1, 2, 4, 5, 5, 5], categories=[5, 4, 3, 2, 1],
                        ordered=True)
        res = s.mode()
        exp = Categorical([5], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)
        s = Categorical([1, 1, 1, 4, 5, 5, 5], categories=[5, 4, 3, 2, 1],
                        ordered=True)
        res = s.mode()
        exp = Categorical([5, 1], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)
        s = Categorical([1, 2, 3, 4, 5], categories=[5, 4, 3, 2, 1],
                        ordered=True)
        res = s.mode()
        exp = Categorical([], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)
        # NaN should not become the mode!
        s = Categorical([np.nan, np.nan, np.nan, 4, 5],
                        categories=[5, 4, 3, 2, 1], ordered=True)
        res = s.mode()
        exp = Categorical([], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)
        s = Categorical([np.nan, np.nan, np.nan, 4, 5, 4],
                        categories=[5, 4, 3, 2, 1], ordered=True)
        res = s.mode()
        exp = Categorical([4], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)
        s = Categorical([np.nan, np.nan, 4, 5, 4], categories=[5, 4, 3, 2, 1],
                        ordered=True)
        res = s.mode()
        exp = Categorical([4], categories=[5, 4, 3, 2, 1], ordered=True)
        tm.assert_categorical_equal(res, exp)

    def test_sort_values(self):

        # unordered cats are sortable
        cat = Categorical(["a", "b", "b", "a"], ordered=False)
        cat.sort_values()

        cat = Categorical(["a", "c", "b", "d"], ordered=True)

        # sort_values
        res = cat.sort_values()
        exp = np.array(["a", "b", "c", "d"], dtype=object)
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, cat.categories)

        cat = Categorical(["a", "c", "b", "d"],
                          categories=["a", "b", "c", "d"], ordered=True)
        res = cat.sort_values()
        exp = np.array(["a", "b", "c", "d"], dtype=object)
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, cat.categories)

        res = cat.sort_values(ascending=False)
        exp = np.array(["d", "c", "b", "a"], dtype=object)
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, cat.categories)

        # sort (inplace order)
        cat1 = cat.copy()
        cat1.sort_values(inplace=True)
        exp = np.array(["a", "b", "c", "d"], dtype=object)
        self.assert_numpy_array_equal(cat1.__array__(), exp)
        self.assert_index_equal(res.categories, cat.categories)

        # reverse
        cat = Categorical(["a", "c", "c", "b", "d"], ordered=True)
        res = cat.sort_values(ascending=False)
        exp_val = np.array(["d", "c", "c", "b", "a"], dtype=object)
        exp_categories = Index(["a", "b", "c", "d"])
        self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_index_equal(res.categories, exp_categories)

    def test_sort_values_na_position(self):
        # see gh-12882
        cat = Categorical([5, 2, np.nan, 2, np.nan], ordered=True)
        exp_categories = Index([2, 5])

        exp = np.array([2.0, 2.0, 5.0, np.nan, np.nan])
        res = cat.sort_values()  # default arguments
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, exp_categories)

        exp = np.array([np.nan, np.nan, 2.0, 2.0, 5.0])
        res = cat.sort_values(ascending=True, na_position='first')
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, exp_categories)

        exp = np.array([np.nan, np.nan, 5.0, 2.0, 2.0])
        res = cat.sort_values(ascending=False, na_position='first')
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, exp_categories)

        exp = np.array([2.0, 2.0, 5.0, np.nan, np.nan])
        res = cat.sort_values(ascending=True, na_position='last')
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, exp_categories)

        exp = np.array([5.0, 2.0, 2.0, np.nan, np.nan])
        res = cat.sort_values(ascending=False, na_position='last')
        self.assert_numpy_array_equal(res.__array__(), exp)
        self.assert_index_equal(res.categories, exp_categories)

        cat = Categorical(["a", "c", "b", "d", np.nan], ordered=True)
        res = cat.sort_values(ascending=False, na_position='last')
        exp_val = np.array(["d", "c", "b", "a", np.nan], dtype=object)
        exp_categories = Index(["a", "b", "c", "d"])
        self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_index_equal(res.categories, exp_categories)

        cat = Categorical(["a", "c", "b", "d", np.nan], ordered=True)
        res = cat.sort_values(ascending=False, na_position='first')
        exp_val = np.array([np.nan, "d", "c", "b", "a"], dtype=object)
        exp_categories = Index(["a", "b", "c", "d"])
        self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_index_equal(res.categories, exp_categories)

    def test_slicing_directly(self):
        cat = Categorical(["a", "b", "c", "d", "a", "b", "c"])
        sliced = cat[3]
        self.assertEqual(sliced, "d")
        sliced = cat[3:5]
        expected = Categorical(["d", "a"], categories=['a', 'b', 'c', 'd'])
        self.assert_numpy_array_equal(sliced._codes, expected._codes)
        tm.assert_index_equal(sliced.categories, expected.categories)

    def test_set_item_nan(self):
        cat = pd.Categorical([1, 2, 3])
        exp = pd.Categorical([1, np.nan, 3], categories=[1, 2, 3])
        cat[1] = np.nan
        tm.assert_categorical_equal(cat, exp)

        # if nan in categories, the proper code should be set!
        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        with tm.assert_produces_warning(FutureWarning):
            cat.set_categories([1, 2, 3, np.nan], rename=True, inplace=True)
        cat[1] = np.nan
        exp = np.array([0, 3, 2, -1], dtype=np.int8)
        self.assert_numpy_array_equal(cat.codes, exp)

        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        with tm.assert_produces_warning(FutureWarning):
            cat.set_categories([1, 2, 3, np.nan], rename=True, inplace=True)
        cat[1:3] = np.nan
        exp = np.array([0, 3, 3, -1], dtype=np.int8)
        self.assert_numpy_array_equal(cat.codes, exp)

        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        with tm.assert_produces_warning(FutureWarning):
            cat.set_categories([1, 2, 3, np.nan], rename=True, inplace=True)
        cat[1:3] = [np.nan, 1]
        exp = np.array([0, 3, 0, -1], dtype=np.int8)
        self.assert_numpy_array_equal(cat.codes, exp)

        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        with tm.assert_produces_warning(FutureWarning):
            cat.set_categories([1, 2, 3, np.nan], rename=True, inplace=True)
        cat[1:3] = [np.nan, np.nan]
        exp = np.array([0, 3, 3, -1], dtype=np.int8)
        self.assert_numpy_array_equal(cat.codes, exp)

        cat = pd.Categorical([1, 2, np.nan, 3], categories=[1, 2, 3])
        with tm.assert_produces_warning(FutureWarning):
            cat.set_categories([1, 2, 3, np.nan], rename=True, inplace=True)
        cat[pd.isnull(cat)] = np.nan
        exp = np.array([0, 1, 3, 2], dtype=np.int8)
        self.assert_numpy_array_equal(cat.codes, exp)

    def test_shift(self):
        # GH 9416
        cat = pd.Categorical(['a', 'b', 'c', 'd', 'a'])

        # shift forward
        sp1 = cat.shift(1)
        xp1 = pd.Categorical([np.nan, 'a', 'b', 'c', 'd'])
        self.assert_categorical_equal(sp1, xp1)
        self.assert_categorical_equal(cat[:-1], sp1[1:])

        # shift back
        sn2 = cat.shift(-2)
        xp2 = pd.Categorical(['c', 'd', 'a', np.nan, np.nan],
                             categories=['a', 'b', 'c', 'd'])
        self.assert_categorical_equal(sn2, xp2)
        self.assert_categorical_equal(cat[2:], sn2[:-2])

        # shift by zero
        self.assert_categorical_equal(cat, cat.shift(0))

    def test_nbytes(self):
        cat = pd.Categorical([1, 2, 3])
        exp = cat._codes.nbytes + cat._categories.values.nbytes
        self.assertEqual(cat.nbytes, exp)

    def test_memory_usage(self):
        cat = pd.Categorical([1, 2, 3])
        self.assertEqual(cat.nbytes, cat.memory_usage())
        self.assertEqual(cat.nbytes, cat.memory_usage(deep=True))

        cat = pd.Categorical(['foo', 'foo', 'bar'])
        self.assertEqual(cat.nbytes, cat.memory_usage())
        self.assertTrue(cat.memory_usage(deep=True) > cat.nbytes)

        # sys.getsizeof will call the .memory_usage with
        # deep=True, and add on some GC overhead
        diff = cat.memory_usage(deep=True) - sys.getsizeof(cat)
        self.assertTrue(abs(diff) < 100)

    def test_searchsorted(self):
        # https://github.com/pydata/pandas/issues/8420
        s1 = pd.Series(['apple', 'bread', 'bread', 'cheese', 'milk'])
        s2 = pd.Series(['apple', 'bread', 'bread', 'cheese', 'milk', 'donuts'])
        c1 = pd.Categorical(s1, ordered=True)
        c2 = pd.Categorical(s2, ordered=True)

        # Single item array
        res = c1.searchsorted(['bread'])
        chk = s1.searchsorted(['bread'])
        exp = np.array([1], dtype=np.intp)
        self.assert_numpy_array_equal(res, exp)
        self.assert_numpy_array_equal(res, chk)

        # Scalar version of single item array
        # Categorical return np.array like pd.Series, but different from
        # np.array.searchsorted()
        res = c1.searchsorted('bread')
        chk = s1.searchsorted('bread')
        exp = np.array([1], dtype=np.intp)
        self.assert_numpy_array_equal(res, exp)
        self.assert_numpy_array_equal(res, chk)

        # Searching for a value that is not present in the Categorical
        res = c1.searchsorted(['bread', 'eggs'])
        chk = s1.searchsorted(['bread', 'eggs'])
        exp = np.array([1, 4], dtype=np.intp)
        self.assert_numpy_array_equal(res, exp)
        self.assert_numpy_array_equal(res, chk)

        # Searching for a value that is not present, to the right
        res = c1.searchsorted(['bread', 'eggs'], side='right')
        chk = s1.searchsorted(['bread', 'eggs'], side='right')
        exp = np.array([3, 4], dtype=np.intp)  # eggs before milk
        self.assert_numpy_array_equal(res, exp)
        self.assert_numpy_array_equal(res, chk)

        # As above, but with a sorter array to reorder an unsorted array
        res = c2.searchsorted(['bread', 'eggs'], side='right',
                              sorter=[0, 1, 2, 3, 5, 4])
        chk = s2.searchsorted(['bread', 'eggs'], side='right',
                              sorter=[0, 1, 2, 3, 5, 4])
        # eggs after donuts, after switching milk and donuts
        exp = np.array([3, 5], dtype=np.intp)
        self.assert_numpy_array_equal(res, exp)
        self.assert_numpy_array_equal(res, chk)

    def test_deprecated_labels(self):
        # TODO: labels is deprecated and should be removed in 0.18 or 2017,
        # whatever is earlier
        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        exp = cat.codes
        with tm.assert_produces_warning(FutureWarning):
            res = cat.labels
        self.assert_numpy_array_equal(res, exp)

    def test_removed_names_produces_warning(self):

        # 10482
        with tm.assert_produces_warning(UserWarning):
            Categorical([0, 1], name="a")

        with tm.assert_produces_warning(UserWarning):
            Categorical.from_codes([1, 2], ["a", "b", "c"], name="a")

    def test_datetime_categorical_comparison(self):
        dt_cat = pd.Categorical(
            pd.date_range('2014-01-01', periods=3), ordered=True)
        self.assert_numpy_array_equal(dt_cat > dt_cat[0],
                                      np.array([False, True, True]))
        self.assert_numpy_array_equal(dt_cat[0] < dt_cat,
                                      np.array([False, True, True]))

    def test_reflected_comparison_with_scalars(self):
        # GH8658
        cat = pd.Categorical([1, 2, 3], ordered=True)
        self.assert_numpy_array_equal(cat > cat[0],
                                      np.array([False, True, True]))
        self.assert_numpy_array_equal(cat[0] < cat,
                                      np.array([False, True, True]))

    def test_comparison_with_unknown_scalars(self):
        # https://github.com/pydata/pandas/issues/9836#issuecomment-92123057
        # and following comparisons with scalars not in categories should raise
        # for unequal comps, but not for equal/not equal
        cat = pd.Categorical([1, 2, 3], ordered=True)

        self.assertRaises(TypeError, lambda: cat < 4)
        self.assertRaises(TypeError, lambda: cat > 4)
        self.assertRaises(TypeError, lambda: 4 < cat)
        self.assertRaises(TypeError, lambda: 4 > cat)

        self.assert_numpy_array_equal(cat == 4,
                                      np.array([False, False, False]))
        self.assert_numpy_array_equal(cat != 4,
                                      np.array([True, True, True]))

    def test_map(self):
        c = pd.Categorical(list('ABABC'), categories=list('CBA'),
                           ordered=True)
        result = c.map(lambda x: x.lower())
        exp = pd.Categorical(list('ababc'), categories=list('cba'),
                             ordered=True)
        tm.assert_categorical_equal(result, exp)

        c = pd.Categorical(list('ABABC'), categories=list('ABC'),
                           ordered=False)
        result = c.map(lambda x: x.lower())
        exp = pd.Categorical(list('ababc'), categories=list('abc'),
                             ordered=False)
        tm.assert_categorical_equal(result, exp)

        result = c.map(lambda x: 1)
        tm.assert_numpy_array_equal(result, np.array([1] * 5, dtype=np.int64))


class TestCategoricalAsBlock(tm.TestCase):
    _multiprocess_can_split_ = True

    def setUp(self):
        self.factor = Categorical.from_array(['a', 'b', 'b', 'a', 'a', 'c',
                                              'c', 'c'])

        df = DataFrame({'value': np.random.randint(0, 10000, 100)})
        labels = ["{0} - {1}".format(i, i + 499) for i in range(0, 10000, 500)]

        df = df.sort_values(by=['value'], ascending=True)
        df['value_group'] = pd.cut(df.value, range(0, 10500, 500), right=False,
                                   labels=labels)
        self.cat = df

    def test_dtypes(self):

        # GH8143
        index = ['cat', 'obj', 'num']
        cat = pd.Categorical(['a', 'b', 'c'])
        obj = pd.Series(['a', 'b', 'c'])
        num = pd.Series([1, 2, 3])
        df = pd.concat([pd.Series(cat), obj, num], axis=1, keys=index)

        result = df.dtypes == 'object'
        expected = Series([False, True, False], index=index)
        tm.assert_series_equal(result, expected)

        result = df.dtypes == 'int64'
        expected = Series([False, False, True], index=index)
        tm.assert_series_equal(result, expected)

        result = df.dtypes == 'category'
        expected = Series([True, False, False], index=index)
        tm.assert_series_equal(result, expected)

    def test_codes_dtypes(self):

        # GH 8453
        result = Categorical(['foo', 'bar', 'baz'])
        self.assertTrue(result.codes.dtype == 'int8')

        result = Categorical(['foo%05d' % i for i in range(400)])
        self.assertTrue(result.codes.dtype == 'int16')

        result = Categorical(['foo%05d' % i for i in range(40000)])
        self.assertTrue(result.codes.dtype == 'int32')

        # adding cats
        result = Categorical(['foo', 'bar', 'baz'])
        self.assertTrue(result.codes.dtype == 'int8')
        result = result.add_categories(['foo%05d' % i for i in range(400)])
        self.assertTrue(result.codes.dtype == 'int16')

        # removing cats
        result = result.remove_categories(['foo%05d' % i for i in range(300)])
        self.assertTrue(result.codes.dtype == 'int8')

    def test_basic(self):

        # test basic creation / coercion of categoricals
        s = Series(self.factor, name='A')
        self.assertEqual(s.dtype, 'category')
        self.assertEqual(len(s), len(self.factor))
        str(s.values)
        str(s)

        # in a frame
        df = DataFrame({'A': self.factor})
        result = df['A']
        tm.assert_series_equal(result, s)
        result = df.iloc[:, 0]
        tm.assert_series_equal(result, s)
        self.assertEqual(len(df), len(self.factor))
        str(df.values)
        str(df)

        df = DataFrame({'A': s})
        result = df['A']
        tm.assert_series_equal(result, s)
        self.assertEqual(len(df), len(self.factor))
        str(df.values)
        str(df)

        # multiples
        df = DataFrame({'A': s, 'B': s, 'C': 1})
        result1 = df['A']
        result2 = df['B']
        tm.assert_series_equal(result1, s)
        tm.assert_series_equal(result2, s, check_names=False)
        self.assertEqual(result2.name, 'B')
        self.assertEqual(len(df), len(self.factor))
        str(df.values)
        str(df)

        # GH8623
        x = pd.DataFrame([[1, 'John P. Doe'], [2, 'Jane Dove'],
                          [1, 'John P. Doe']],
                         columns=['person_id', 'person_name'])
        x['person_name'] = pd.Categorical(x.person_name
                                          )  # doing this breaks transform

        expected = x.iloc[0].person_name
        result = x.person_name.iloc[0]
        self.assertEqual(result, expected)

        result = x.person_name[0]
        self.assertEqual(result, expected)

        result = x.person_name.loc[0]
        self.assertEqual(result, expected)

    def test_creation_astype(self):
        l = ["a", "b", "c", "a"]
        s = pd.Series(l)
        exp = pd.Series(Categorical(l))
        res = s.astype('category')
        tm.assert_series_equal(res, exp)

        l = [1, 2, 3, 1]
        s = pd.Series(l)
        exp = pd.Series(Categorical(l))
        res = s.astype('category')
        tm.assert_series_equal(res, exp)

        df = pd.DataFrame({"cats": [1, 2, 3, 4, 5, 6],
                           "vals": [1, 2, 3, 4, 5, 6]})
        cats = Categorical([1, 2, 3, 4, 5, 6])
        exp_df = pd.DataFrame({"cats": cats, "vals": [1, 2, 3, 4, 5, 6]})
        df["cats"] = df["cats"].astype("category")
        tm.assert_frame_equal(exp_df, df)

        df = pd.DataFrame({"cats": ['a', 'b', 'b', 'a', 'a', 'd'],
                           "vals": [1, 2, 3, 4, 5, 6]})
        cats = Categorical(['a', 'b', 'b', 'a', 'a', 'd'])
        exp_df = pd.DataFrame({"cats": cats, "vals": [1, 2, 3, 4, 5, 6]})
        df["cats"] = df["cats"].astype("category")
        tm.assert_frame_equal(exp_df, df)

        # with keywords
        l = ["a", "b", "c", "a"]
        s = pd.Series(l)
        exp = pd.Series(Categorical(l, ordered=True))
        res = s.astype('category', ordered=True)
        tm.assert_series_equal(res, exp)

        exp = pd.Series(Categorical(
            l, categories=list('abcdef'), ordered=True))
        res = s.astype('category', categories=list('abcdef'), ordered=True)
        tm.assert_series_equal(res, exp)

    def test_construction_series(self):

        l = [1, 2, 3, 1]
        exp = Series(l).astype('category')
        res = Series(l, dtype='category')
        tm.assert_series_equal(res, exp)

        l = ["a", "b", "c", "a"]
        exp = Series(l).astype('category')
        res = Series(l, dtype='category')
        tm.assert_series_equal(res, exp)

        # insert into frame with different index
        # GH 8076
        index = pd.date_range('20000101', periods=3)
        expected = Series(Categorical(values=[np.nan, np.nan, np.nan],
                                      categories=['a', 'b', 'c']))
        expected.index = index

        expected = DataFrame({'x': expected})
        df = DataFrame(
            {'x': Series(['a', 'b', 'c'], dtype='category')}, index=index)
        tm.assert_frame_equal(df, expected)

    def test_construction_frame(self):

        # GH8626

        # dict creation
        df = DataFrame({'A': list('abc')}, dtype='category')
        expected = Series(list('abc'), dtype='category', name='A')
        tm.assert_series_equal(df['A'], expected)

        # to_frame
        s = Series(list('abc'), dtype='category')
        result = s.to_frame()
        expected = Series(list('abc'), dtype='category', name=0)
        tm.assert_series_equal(result[0], expected)
        result = s.to_frame(name='foo')
        expected = Series(list('abc'), dtype='category', name='foo')
        tm.assert_series_equal(result['foo'], expected)

        # list-like creation
        df = DataFrame(list('abc'), dtype='category')
        expected = Series(list('abc'), dtype='category', name=0)
        tm.assert_series_equal(df[0], expected)

        # ndim != 1
        df = DataFrame([pd.Categorical(list('abc'))])
        expected = DataFrame({0: Series(list('abc'), dtype='category')})
        tm.assert_frame_equal(df, expected)

        df = DataFrame([pd.Categorical(list('abc')), pd.Categorical(list(
            'abd'))])
        expected = DataFrame({0: Series(list('abc'), dtype='category'),
                              1: Series(list('abd'), dtype='category')},
                             columns=[0, 1])
        tm.assert_frame_equal(df, expected)

        # mixed
        df = DataFrame([pd.Categorical(list('abc')), list('def')])
        expected = DataFrame({0: Series(list('abc'), dtype='category'),
                              1: list('def')}, columns=[0, 1])
        tm.assert_frame_equal(df, expected)

        # invalid (shape)
        self.assertRaises(
            ValueError,
            lambda: DataFrame([pd.Categorical(list('abc')),
                               pd.Categorical(list('abdefg'))]))

        # ndim > 1
        self.assertRaises(NotImplementedError,
                          lambda: pd.Categorical(np.array([list('abcd')])))

    def test_reshaping(self):

        p = tm.makePanel()
        p['str'] = 'foo'
        df = p.to_frame()
        df['category'] = df['str'].astype('category')
        result = df['category'].unstack()

        c = Categorical(['foo'] * len(p.major_axis))
        expected = DataFrame({'A': c.copy(),
                              'B': c.copy(),
                              'C': c.copy(),
                              'D': c.copy()},
                             columns=Index(list('ABCD'), name='minor'),
                             index=p.major_axis.set_names('major'))
        tm.assert_frame_equal(result, expected)

    def test_reindex(self):

        index = pd.date_range('20000101', periods=3)

        # reindexing to an invalid Categorical
        s = Series(['a', 'b', 'c'], dtype='category')
        result = s.reindex(index)
        expected = Series(Categorical(values=[np.nan, np.nan, np.nan],
                                      categories=['a', 'b', 'c']))
        expected.index = index
        tm.assert_series_equal(result, expected)

        # partial reindexing
        expected = Series(Categorical(values=['b', 'c'], categories=['a', 'b',
                                                                     'c']))
        expected.index = [1, 2]
        result = s.reindex([1, 2])
        tm.assert_series_equal(result, expected)

        expected = Series(Categorical(
            values=['c', np.nan], categories=['a', 'b', 'c']))
        expected.index = [2, 3]
        result = s.reindex([2, 3])
        tm.assert_series_equal(result, expected)

    def test_sideeffects_free(self):
        # Passing a categorical to a Series and then changing values in either
        # the series or the categorical should not change the values in the
        # other one, IF you specify copy!
        cat = Categorical(["a", "b", "c", "a"])
        s = pd.Series(cat, copy=True)
        self.assertFalse(s.cat is cat)
        s.cat.categories = [1, 2, 3]
        exp_s = np.array([1, 2, 3, 1], dtype=np.int64)
        exp_cat = np.array(["a", "b", "c", "a"], dtype=np.object_)
        self.assert_numpy_array_equal(s.__array__(), exp_s)
        self.assert_numpy_array_equal(cat.__array__(), exp_cat)

        # setting
        s[0] = 2
        exp_s2 = np.array([2, 2, 3, 1], dtype=np.int64)
        self.assert_numpy_array_equal(s.__array__(), exp_s2)
        self.assert_numpy_array_equal(cat.__array__(), exp_cat)

        # however, copy is False by default
        # so this WILL change values
        cat = Categorical(["a", "b", "c", "a"])
        s = pd.Series(cat)
        self.assertTrue(s.values is cat)
        s.cat.categories = [1, 2, 3]
        exp_s = np.array([1, 2, 3, 1], dtype=np.int64)
        self.assert_numpy_array_equal(s.__array__(), exp_s)
        self.assert_numpy_array_equal(cat.__array__(), exp_s)

        s[0] = 2
        exp_s2 = np.array([2, 2, 3, 1], dtype=np.int64)
        self.assert_numpy_array_equal(s.__array__(), exp_s2)
        self.assert_numpy_array_equal(cat.__array__(), exp_s2)

    def test_nan_handling(self):

        # Nans are represented as -1 in labels
        s = Series(Categorical(["a", "b", np.nan, "a"]))
        self.assert_index_equal(s.cat.categories, Index(["a", "b"]))
        self.assert_numpy_array_equal(s.values.codes,
                                      np.array([0, 1, -1, 0], dtype=np.int8))

        # If categories have nan included, the label should point to that
        # instead
        with tm.assert_produces_warning(FutureWarning):
            s2 = Series(Categorical(["a", "b", np.nan, "a"],
                                    categories=["a", "b", np.nan]))

        exp_cat = Index(["a", "b", np.nan])
        self.assert_index_equal(s2.cat.categories, exp_cat)
        self.assert_numpy_array_equal(s2.values.codes,
                                      np.array([0, 1, 2, 0], dtype=np.int8))

        # Changing categories should also make the replaced category np.nan
        s3 = Series(Categorical(["a", "b", "c", "a"]))
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            s3.cat.categories = ["a", "b", np.nan]

        exp_cat = Index(["a", "b", np.nan])
        self.assert_index_equal(s3.cat.categories, exp_cat)
        self.assert_numpy_array_equal(s3.values.codes,
                                      np.array([0, 1, 2, 0], dtype=np.int8))

    def test_cat_accessor(self):
        s = Series(Categorical(["a", "b", np.nan, "a"]))
        self.assert_index_equal(s.cat.categories, Index(["a", "b"]))
        self.assertEqual(s.cat.ordered, False)
        exp = Categorical(["a", "b", np.nan, "a"], categories=["b", "a"])
        s.cat.set_categories(["b", "a"], inplace=True)
        tm.assert_categorical_equal(s.values, exp)

        res = s.cat.set_categories(["b", "a"])
        tm.assert_categorical_equal(res.values, exp)

        exp = Categorical(["a", "b", np.nan, "a"], categories=["b", "a"])
        s[:] = "a"
        s = s.cat.remove_unused_categories()
        self.assert_index_equal(s.cat.categories, Index(["a"]))

    def test_sequence_like(self):

        # GH 7839
        # make sure can iterate
        df = DataFrame({"id": [1, 2, 3, 4, 5, 6],
                        "raw_grade": ['a', 'b', 'b', 'a', 'a', 'e']})
        df['grade'] = Categorical(df['raw_grade'])

        # basic sequencing testing
        result = list(df.grade.values)
        expected = np.array(df.grade.values).tolist()
        tm.assert_almost_equal(result, expected)

        # iteration
        for t in df.itertuples(index=False):
            str(t)

        for row, s in df.iterrows():
            str(s)

        for c, col in df.iteritems():
            str(s)

    def test_series_delegations(self):

        # invalid accessor
        self.assertRaises(AttributeError, lambda: Series([1, 2, 3]).cat)
        tm.assertRaisesRegexp(
            AttributeError,
            r"Can only use .cat accessor with a 'category' dtype",
            lambda: Series([1, 2, 3]).cat)
        self.assertRaises(AttributeError, lambda: Series(['a', 'b', 'c']).cat)
        self.assertRaises(AttributeError, lambda: Series(np.arange(5.)).cat)
        self.assertRaises(AttributeError,
                          lambda: Series([Timestamp('20130101')]).cat)

        # Series should delegate calls to '.categories', '.codes', '.ordered'
        # and the methods '.set_categories()' 'drop_unused_categories()' to the
        # categorical
        s = Series(Categorical(["a", "b", "c", "a"], ordered=True))
        exp_categories = Index(["a", "b", "c"])
        tm.assert_index_equal(s.cat.categories, exp_categories)
        s.cat.categories = [1, 2, 3]
        exp_categories = Index([1, 2, 3])
        self.assert_index_equal(s.cat.categories, exp_categories)

        exp_codes = Series([0, 1, 2, 0], dtype='int8')
        tm.assert_series_equal(s.cat.codes, exp_codes)

        self.assertEqual(s.cat.ordered, True)
        s = s.cat.as_unordered()
        self.assertEqual(s.cat.ordered, False)
        s.cat.as_ordered(inplace=True)
        self.assertEqual(s.cat.ordered, True)

        # reorder
        s = Series(Categorical(["a", "b", "c", "a"], ordered=True))
        exp_categories = Index(["c", "b", "a"])
        exp_values = np.array(["a", "b", "c", "a"], dtype=np.object_)
        s = s.cat.set_categories(["c", "b", "a"])
        tm.assert_index_equal(s.cat.categories, exp_categories)
        self.assert_numpy_array_equal(s.values.__array__(), exp_values)
        self.assert_numpy_array_equal(s.__array__(), exp_values)

        # remove unused categories
        s = Series(Categorical(["a", "b", "b", "a"], categories=["a", "b", "c"
                                                                 ]))
        exp_categories = Index(["a", "b"])
        exp_values = np.array(["a", "b", "b", "a"], dtype=np.object_)
        s = s.cat.remove_unused_categories()
        self.assert_index_equal(s.cat.categories, exp_categories)
        self.assert_numpy_array_equal(s.values.__array__(), exp_values)
        self.assert_numpy_array_equal(s.__array__(), exp_values)

        # This method is likely to be confused, so test that it raises an error
        # on wrong inputs:
        def f():
            s.set_categories([4, 3, 2, 1])

        self.assertRaises(Exception, f)
        # right: s.cat.set_categories([4,3,2,1])

    def test_series_functions_no_warnings(self):
        df = pd.DataFrame({'value': np.random.randint(0, 100, 20)})
        labels = ["{0} - {1}".format(i, i + 9) for i in range(0, 100, 10)]
        with tm.assert_produces_warning(False):
            df['group'] = pd.cut(df.value, range(0, 105, 10), right=False,
                                 labels=labels)

    def test_assignment_to_dataframe(self):
        # assignment
        df = DataFrame({'value': np.array(
            np.random.randint(0, 10000, 100), dtype='int32')})
        labels = ["{0} - {1}".format(i, i + 499) for i in range(0, 10000, 500)]

        df = df.sort_values(by=['value'], ascending=True)
        s = pd.cut(df.value, range(0, 10500, 500), right=False, labels=labels)
        d = s.values
        df['D'] = d
        str(df)

        result = df.dtypes
        expected = Series(
            [np.dtype('int32'), CategoricalDtype()], index=['value', 'D'])
        tm.assert_series_equal(result, expected)

        df['E'] = s
        str(df)

        result = df.dtypes
        expected = Series([np.dtype('int32'), CategoricalDtype(),
                           CategoricalDtype()],
                          index=['value', 'D', 'E'])
        tm.assert_series_equal(result, expected)

        result1 = df['D']
        result2 = df['E']
        self.assert_categorical_equal(result1._data._block.values, d)

        # sorting
        s.name = 'E'
        self.assert_series_equal(result2.sort_index(), s.sort_index())

        cat = pd.Categorical([1, 2, 3, 10], categories=[1, 2, 3, 4, 10])
        df = pd.DataFrame(pd.Series(cat))

    def test_describe(self):

        # Categoricals should not show up together with numerical columns
        result = self.cat.describe()
        self.assertEqual(len(result.columns), 1)

        # In a frame, describe() for the cat should be the same as for string
        # arrays (count, unique, top, freq)

        cat = Categorical(["a", "b", "b", "b"], categories=['a', 'b', 'c'],
                          ordered=True)
        s = Series(cat)
        result = s.describe()
        expected = Series([4, 2, "b", 3],
                          index=['count', 'unique', 'top', 'freq'])
        tm.assert_series_equal(result, expected)

        cat = pd.Series(pd.Categorical(["a", "b", "c", "c"]))
        df3 = pd.DataFrame({"cat": cat, "s": ["a", "b", "c", "c"]})
        res = df3.describe()
        self.assert_numpy_array_equal(res["cat"].values, res["s"].values)

    def test_repr(self):
        a = pd.Series(pd.Categorical([1, 2, 3, 4]))
        exp = u("0    1\n1    2\n2    3\n3    4\n" +
                "dtype: category\nCategories (4, int64): [1, 2, 3, 4]")

        self.assertEqual(exp, a.__unicode__())

        a = pd.Series(pd.Categorical(["a", "b"] * 25))
        exp = u("0     a\n1     b\n" + "     ..\n" + "48    a\n49    b\n" +
                "dtype: category\nCategories (2, object): [a, b]")
        with option_context("display.max_rows", 5):
            self.assertEqual(exp, repr(a))

        levs = list("abcdefghijklmnopqrstuvwxyz")
        a = pd.Series(pd.Categorical(
            ["a", "b"], categories=levs, ordered=True))
        exp = u("0    a\n1    b\n" + "dtype: category\n"
                "Categories (26, object): [a < b < c < d ... w < x < y < z]")
        self.assertEqual(exp, a.__unicode__())

    def test_categorical_repr(self):
        c = pd.Categorical([1, 2, 3])
        exp = """[1, 2, 3]
Categories (3, int64): [1, 2, 3]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical([1, 2, 3, 1, 2, 3], categories=[1, 2, 3])
        exp = """[1, 2, 3, 1, 2, 3]
Categories (3, int64): [1, 2, 3]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical([1, 2, 3, 4, 5] * 10)
        exp = """[1, 2, 3, 4, 5, ..., 1, 2, 3, 4, 5]
Length: 50
Categories (5, int64): [1, 2, 3, 4, 5]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(np.arange(20))
        exp = """[0, 1, 2, 3, 4, ..., 15, 16, 17, 18, 19]
Length: 20
Categories (20, int64): [0, 1, 2, 3, ..., 16, 17, 18, 19]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_ordered(self):
        c = pd.Categorical([1, 2, 3], ordered=True)
        exp = """[1, 2, 3]
Categories (3, int64): [1 < 2 < 3]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical([1, 2, 3, 1, 2, 3], categories=[1, 2, 3],
                           ordered=True)
        exp = """[1, 2, 3, 1, 2, 3]
Categories (3, int64): [1 < 2 < 3]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical([1, 2, 3, 4, 5] * 10, ordered=True)
        exp = """[1, 2, 3, 4, 5, ..., 1, 2, 3, 4, 5]
Length: 50
Categories (5, int64): [1 < 2 < 3 < 4 < 5]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(np.arange(20), ordered=True)
        exp = """[0, 1, 2, 3, 4, ..., 15, 16, 17, 18, 19]
Length: 20
Categories (20, int64): [0 < 1 < 2 < 3 ... 16 < 17 < 18 < 19]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_datetime(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        c = pd.Categorical(idx)

        # TODO(wesm): exceeding 80 characters in the console is not good
        # behavior
        exp = (
            "[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, "
            "2011-01-01 12:00:00, 2011-01-01 13:00:00]\n"
            "Categories (5, datetime64[ns]): [2011-01-01 09:00:00, "
            "2011-01-01 10:00:00, 2011-01-01 11:00:00,\n"
            "                                 2011-01-01 12:00:00, "
            "2011-01-01 13:00:00]""")
        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = (
            "[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, "
            "2011-01-01 12:00:00, 2011-01-01 13:00:00, 2011-01-01 09:00:00, "
            "2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, "
            "2011-01-01 13:00:00]\n"
            "Categories (5, datetime64[ns]): [2011-01-01 09:00:00, "
            "2011-01-01 10:00:00, 2011-01-01 11:00:00,\n"
            "                                 2011-01-01 12:00:00, "
            "2011-01-01 13:00:00]")

        self.assertEqual(repr(c), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        c = pd.Categorical(idx)
        exp = (
            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, "
            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, "
            "2011-01-01 13:00:00-05:00]\n"
            "Categories (5, datetime64[ns, US/Eastern]): "
            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00,\n"
            "                                             "
            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00,\n"
            "                                             "
            "2011-01-01 13:00:00-05:00]")

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = (
            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, "
            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, "
            "2011-01-01 13:00:00-05:00, 2011-01-01 09:00:00-05:00, "
            "2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, "
            "2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]\n"
            "Categories (5, datetime64[ns, US/Eastern]): "
            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00,\n"
            "                                             "
            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00,\n"
            "                                             "
            "2011-01-01 13:00:00-05:00]")

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_datetime_ordered(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        c = pd.Categorical(idx, ordered=True)
        exp = """[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00]
Categories (5, datetime64[ns]): [2011-01-01 09:00:00 < 2011-01-01 10:00:00 < 2011-01-01 11:00:00 <
                                 2011-01-01 12:00:00 < 2011-01-01 13:00:00]"""  # noqa

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00, 2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00]
Categories (5, datetime64[ns]): [2011-01-01 09:00:00 < 2011-01-01 10:00:00 < 2011-01-01 11:00:00 <
                                 2011-01-01 12:00:00 < 2011-01-01 13:00:00]"""  # noqa

        self.assertEqual(repr(c), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        c = pd.Categorical(idx, ordered=True)
        exp = """[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]
Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00 < 2011-01-01 10:00:00-05:00 <
                                             2011-01-01 11:00:00-05:00 < 2011-01-01 12:00:00-05:00 <
                                             2011-01-01 13:00:00-05:00]"""  # noqa

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00, 2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]
Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00 < 2011-01-01 10:00:00-05:00 <
                                             2011-01-01 11:00:00-05:00 < 2011-01-01 12:00:00-05:00 <
                                             2011-01-01 13:00:00-05:00]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_period(self):
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        c = pd.Categorical(idx)
        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
Categories (5, period): [2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00,
                         2011-01-01 13:00]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00, 2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
Categories (5, period): [2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00,
                         2011-01-01 13:00]"""

        self.assertEqual(repr(c), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        c = pd.Categorical(idx)
        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
Categories (5, period): [2011-01, 2011-02, 2011-03, 2011-04, 2011-05]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05, 2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
Categories (5, period): [2011-01, 2011-02, 2011-03, 2011-04, 2011-05]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_period_ordered(self):
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        c = pd.Categorical(idx, ordered=True)
        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
Categories (5, period): [2011-01-01 09:00 < 2011-01-01 10:00 < 2011-01-01 11:00 < 2011-01-01 12:00 <
                         2011-01-01 13:00]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00, 2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
Categories (5, period): [2011-01-01 09:00 < 2011-01-01 10:00 < 2011-01-01 11:00 < 2011-01-01 12:00 <
                         2011-01-01 13:00]"""

        self.assertEqual(repr(c), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        c = pd.Categorical(idx, ordered=True)
        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
Categories (5, period): [2011-01 < 2011-02 < 2011-03 < 2011-04 < 2011-05]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05, 2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
Categories (5, period): [2011-01 < 2011-02 < 2011-03 < 2011-04 < 2011-05]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_timedelta(self):
        idx = pd.timedelta_range('1 days', periods=5)
        c = pd.Categorical(idx)
        exp = """[1 days, 2 days, 3 days, 4 days, 5 days]
Categories (5, timedelta64[ns]): [1 days, 2 days, 3 days, 4 days, 5 days]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = """[1 days, 2 days, 3 days, 4 days, 5 days, 1 days, 2 days, 3 days, 4 days, 5 days]
Categories (5, timedelta64[ns]): [1 days, 2 days, 3 days, 4 days, 5 days]"""

        self.assertEqual(repr(c), exp)

        idx = pd.timedelta_range('1 hours', periods=20)
        c = pd.Categorical(idx)
        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
Length: 20
Categories (20, timedelta64[ns]): [0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00,
                                   3 days 01:00:00, ..., 16 days 01:00:00, 17 days 01:00:00,
                                   18 days 01:00:00, 19 days 01:00:00]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx)
        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
Length: 40
Categories (20, timedelta64[ns]): [0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00,
                                   3 days 01:00:00, ..., 16 days 01:00:00, 17 days 01:00:00,
                                   18 days 01:00:00, 19 days 01:00:00]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_repr_timedelta_ordered(self):
        idx = pd.timedelta_range('1 days', periods=5)
        c = pd.Categorical(idx, ordered=True)
        exp = """[1 days, 2 days, 3 days, 4 days, 5 days]
Categories (5, timedelta64[ns]): [1 days < 2 days < 3 days < 4 days < 5 days]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[1 days, 2 days, 3 days, 4 days, 5 days, 1 days, 2 days, 3 days, 4 days, 5 days]
Categories (5, timedelta64[ns]): [1 days < 2 days < 3 days < 4 days < 5 days]"""

        self.assertEqual(repr(c), exp)

        idx = pd.timedelta_range('1 hours', periods=20)
        c = pd.Categorical(idx, ordered=True)
        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
Length: 20
Categories (20, timedelta64[ns]): [0 days 01:00:00 < 1 days 01:00:00 < 2 days 01:00:00 <
                                   3 days 01:00:00 ... 16 days 01:00:00 < 17 days 01:00:00 <
                                   18 days 01:00:00 < 19 days 01:00:00]"""

        self.assertEqual(repr(c), exp)

        c = pd.Categorical(idx.append(idx), categories=idx, ordered=True)
        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
Length: 40
Categories (20, timedelta64[ns]): [0 days 01:00:00 < 1 days 01:00:00 < 2 days 01:00:00 <
                                   3 days 01:00:00 ... 16 days 01:00:00 < 17 days 01:00:00 <
                                   18 days 01:00:00 < 19 days 01:00:00]"""

        self.assertEqual(repr(c), exp)

    def test_categorical_series_repr(self):
        s = pd.Series(pd.Categorical([1, 2, 3]))
        exp = """0    1
1    2
2    3
dtype: category
Categories (3, int64): [1, 2, 3]"""

        self.assertEqual(repr(s), exp)

        s = pd.Series(pd.Categorical(np.arange(10)))
        exp = """0    0
1    1
2    2
3    3
4    4
5    5
6    6
7    7
8    8
9    9
dtype: category
Categories (10, int64): [0, 1, 2, 3, ..., 6, 7, 8, 9]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_ordered(self):
        s = pd.Series(pd.Categorical([1, 2, 3], ordered=True))
        exp = """0    1
1    2
2    3
dtype: category
Categories (3, int64): [1 < 2 < 3]"""

        self.assertEqual(repr(s), exp)

        s = pd.Series(pd.Categorical(np.arange(10), ordered=True))
        exp = """0    0
1    1
2    2
3    3
4    4
5    5
6    6
7    7
8    8
9    9
dtype: category
Categories (10, int64): [0 < 1 < 2 < 3 ... 6 < 7 < 8 < 9]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_datetime(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        s = pd.Series(pd.Categorical(idx))
        exp = """0   2011-01-01 09:00:00
1   2011-01-01 10:00:00
2   2011-01-01 11:00:00
3   2011-01-01 12:00:00
4   2011-01-01 13:00:00
dtype: category
Categories (5, datetime64[ns]): [2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00,
                                 2011-01-01 12:00:00, 2011-01-01 13:00:00]"""

        self.assertEqual(repr(s), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        s = pd.Series(pd.Categorical(idx))
        exp = """0   2011-01-01 09:00:00-05:00
1   2011-01-01 10:00:00-05:00
2   2011-01-01 11:00:00-05:00
3   2011-01-01 12:00:00-05:00
4   2011-01-01 13:00:00-05:00
dtype: category
Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00,
                                             2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00,
                                             2011-01-01 13:00:00-05:00]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_datetime_ordered(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   2011-01-01 09:00:00
1   2011-01-01 10:00:00
2   2011-01-01 11:00:00
3   2011-01-01 12:00:00
4   2011-01-01 13:00:00
dtype: category
Categories (5, datetime64[ns]): [2011-01-01 09:00:00 < 2011-01-01 10:00:00 < 2011-01-01 11:00:00 <
                                 2011-01-01 12:00:00 < 2011-01-01 13:00:00]"""

        self.assertEqual(repr(s), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   2011-01-01 09:00:00-05:00
1   2011-01-01 10:00:00-05:00
2   2011-01-01 11:00:00-05:00
3   2011-01-01 12:00:00-05:00
4   2011-01-01 13:00:00-05:00
dtype: category
Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00 < 2011-01-01 10:00:00-05:00 <
                                             2011-01-01 11:00:00-05:00 < 2011-01-01 12:00:00-05:00 <
                                             2011-01-01 13:00:00-05:00]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_period(self):
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        s = pd.Series(pd.Categorical(idx))
        exp = """0   2011-01-01 09:00
1   2011-01-01 10:00
2   2011-01-01 11:00
3   2011-01-01 12:00
4   2011-01-01 13:00
dtype: category
Categories (5, period): [2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00,
                         2011-01-01 13:00]"""

        self.assertEqual(repr(s), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        s = pd.Series(pd.Categorical(idx))
        exp = """0   2011-01
1   2011-02
2   2011-03
3   2011-04
4   2011-05
dtype: category
Categories (5, period): [2011-01, 2011-02, 2011-03, 2011-04, 2011-05]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_period_ordered(self):
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   2011-01-01 09:00
1   2011-01-01 10:00
2   2011-01-01 11:00
3   2011-01-01 12:00
4   2011-01-01 13:00
dtype: category
Categories (5, period): [2011-01-01 09:00 < 2011-01-01 10:00 < 2011-01-01 11:00 < 2011-01-01 12:00 <
                         2011-01-01 13:00]"""

        self.assertEqual(repr(s), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   2011-01
1   2011-02
2   2011-03
3   2011-04
4   2011-05
dtype: category
Categories (5, period): [2011-01 < 2011-02 < 2011-03 < 2011-04 < 2011-05]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_timedelta(self):
        idx = pd.timedelta_range('1 days', periods=5)
        s = pd.Series(pd.Categorical(idx))
        exp = """0   1 days
1   2 days
2   3 days
3   4 days
4   5 days
dtype: category
Categories (5, timedelta64[ns]): [1 days, 2 days, 3 days, 4 days, 5 days]"""

        self.assertEqual(repr(s), exp)

        idx = pd.timedelta_range('1 hours', periods=10)
        s = pd.Series(pd.Categorical(idx))
        exp = """0   0 days 01:00:00
1   1 days 01:00:00
2   2 days 01:00:00
3   3 days 01:00:00
4   4 days 01:00:00
5   5 days 01:00:00
6   6 days 01:00:00
7   7 days 01:00:00
8   8 days 01:00:00
9   9 days 01:00:00
dtype: category
Categories (10, timedelta64[ns]): [0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00,
                                   3 days 01:00:00, ..., 6 days 01:00:00, 7 days 01:00:00,
                                   8 days 01:00:00, 9 days 01:00:00]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_series_repr_timedelta_ordered(self):
        idx = pd.timedelta_range('1 days', periods=5)
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   1 days
1   2 days
2   3 days
3   4 days
4   5 days
dtype: category
Categories (5, timedelta64[ns]): [1 days < 2 days < 3 days < 4 days < 5 days]"""

        self.assertEqual(repr(s), exp)

        idx = pd.timedelta_range('1 hours', periods=10)
        s = pd.Series(pd.Categorical(idx, ordered=True))
        exp = """0   0 days 01:00:00
1   1 days 01:00:00
2   2 days 01:00:00
3   3 days 01:00:00
4   4 days 01:00:00
5   5 days 01:00:00
6   6 days 01:00:00
7   7 days 01:00:00
8   8 days 01:00:00
9   9 days 01:00:00
dtype: category
Categories (10, timedelta64[ns]): [0 days 01:00:00 < 1 days 01:00:00 < 2 days 01:00:00 <
                                   3 days 01:00:00 ... 6 days 01:00:00 < 7 days 01:00:00 <
                                   8 days 01:00:00 < 9 days 01:00:00]"""

        self.assertEqual(repr(s), exp)

    def test_categorical_index_repr(self):
        idx = pd.CategoricalIndex(pd.Categorical([1, 2, 3]))
        exp = """CategoricalIndex([1, 2, 3], categories=[1, 2, 3], ordered=False, dtype='category')"""
        self.assertEqual(repr(idx), exp)

        i = pd.CategoricalIndex(pd.Categorical(np.arange(10)))
        exp = """CategoricalIndex([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], categories=[0, 1, 2, 3, 4, 5, 6, 7, ...], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_ordered(self):
        i = pd.CategoricalIndex(pd.Categorical([1, 2, 3], ordered=True))
        exp = """CategoricalIndex([1, 2, 3], categories=[1, 2, 3], ordered=True, dtype='category')"""
        self.assertEqual(repr(i), exp)

        i = pd.CategoricalIndex(pd.Categorical(np.arange(10), ordered=True))
        exp = """CategoricalIndex([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], categories=[0, 1, 2, 3, 4, 5, 6, 7, ...], ordered=True, dtype='category')"""
        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_datetime(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00:00', '2011-01-01 10:00:00',
                  '2011-01-01 11:00:00', '2011-01-01 12:00:00',
                  '2011-01-01 13:00:00'],
                 categories=[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00], ordered=False, dtype='category')"""

        self.assertEqual(repr(i), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
                  '2011-01-01 13:00:00-05:00'],
                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=False, dtype='category')"""

        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_datetime_ordered(self):
        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['2011-01-01 09:00:00', '2011-01-01 10:00:00',
                  '2011-01-01 11:00:00', '2011-01-01 12:00:00',
                  '2011-01-01 13:00:00'],
                 categories=[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00], ordered=True, dtype='category')"""

        self.assertEqual(repr(i), exp)

        idx = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                            tz='US/Eastern')
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
                  '2011-01-01 13:00:00-05:00'],
                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=True, dtype='category')"""

        self.assertEqual(repr(i), exp)

        i = pd.CategoricalIndex(pd.Categorical(idx.append(idx), ordered=True))
        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
                  '2011-01-01 13:00:00-05:00', '2011-01-01 09:00:00-05:00',
                  '2011-01-01 10:00:00-05:00', '2011-01-01 11:00:00-05:00',
                  '2011-01-01 12:00:00-05:00', '2011-01-01 13:00:00-05:00'],
                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=True, dtype='category')"""

        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_period(self):
        # test all length
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=1)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00'], categories=[2011-01-01 09:00], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=2)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00'], categories=[2011-01-01 09:00, 2011-01-01 10:00], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=3)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00'], categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
                  '2011-01-01 12:00', '2011-01-01 13:00'],
                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=False, dtype='category')"""

        self.assertEqual(repr(i), exp)

        i = pd.CategoricalIndex(pd.Categorical(idx.append(idx)))
        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
                  '2011-01-01 12:00', '2011-01-01 13:00', '2011-01-01 09:00',
                  '2011-01-01 10:00', '2011-01-01 11:00', '2011-01-01 12:00',
                  '2011-01-01 13:00'],
                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=False, dtype='category')"""

        self.assertEqual(repr(i), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['2011-01', '2011-02', '2011-03', '2011-04', '2011-05'], categories=[2011-01, 2011-02, 2011-03, 2011-04, 2011-05], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_period_ordered(self):
        idx = pd.period_range('2011-01-01 09:00', freq='H', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
                  '2011-01-01 12:00', '2011-01-01 13:00'],
                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=True, dtype='category')"""

        self.assertEqual(repr(i), exp)

        idx = pd.period_range('2011-01', freq='M', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['2011-01', '2011-02', '2011-03', '2011-04', '2011-05'], categories=[2011-01, 2011-02, 2011-03, 2011-04, 2011-05], ordered=True, dtype='category')"""
        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_timedelta(self):
        idx = pd.timedelta_range('1 days', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['1 days', '2 days', '3 days', '4 days', '5 days'], categories=[1 days 00:00:00, 2 days 00:00:00, 3 days 00:00:00, 4 days 00:00:00, 5 days 00:00:00], ordered=False, dtype='category')"""
        self.assertEqual(repr(i), exp)

        idx = pd.timedelta_range('1 hours', periods=10)
        i = pd.CategoricalIndex(pd.Categorical(idx))
        exp = """CategoricalIndex(['0 days 01:00:00', '1 days 01:00:00', '2 days 01:00:00',
                  '3 days 01:00:00', '4 days 01:00:00', '5 days 01:00:00',
                  '6 days 01:00:00', '7 days 01:00:00', '8 days 01:00:00',
                  '9 days 01:00:00'],
                 categories=[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, 5 days 01:00:00, 6 days 01:00:00, 7 days 01:00:00, ...], ordered=False, dtype='category')"""

        self.assertEqual(repr(i), exp)

    def test_categorical_index_repr_timedelta_ordered(self):
        idx = pd.timedelta_range('1 days', periods=5)
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['1 days', '2 days', '3 days', '4 days', '5 days'], categories=[1 days 00:00:00, 2 days 00:00:00, 3 days 00:00:00, 4 days 00:00:00, 5 days 00:00:00], ordered=True, dtype='category')"""
        self.assertEqual(repr(i), exp)

        idx = pd.timedelta_range('1 hours', periods=10)
        i = pd.CategoricalIndex(pd.Categorical(idx, ordered=True))
        exp = """CategoricalIndex(['0 days 01:00:00', '1 days 01:00:00', '2 days 01:00:00',
                  '3 days 01:00:00', '4 days 01:00:00', '5 days 01:00:00',
                  '6 days 01:00:00', '7 days 01:00:00', '8 days 01:00:00',
                  '9 days 01:00:00'],
                 categories=[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, 5 days 01:00:00, 6 days 01:00:00, 7 days 01:00:00, ...], ordered=True, dtype='category')"""

        self.assertEqual(repr(i), exp)

    def test_categorical_frame(self):
        # normal DataFrame
        dt = pd.date_range('2011-01-01 09:00', freq='H', periods=5,
                           tz='US/Eastern')
        p = pd.period_range('2011-01', freq='M', periods=5)
        df = pd.DataFrame({'dt': dt, 'p': p})
        exp = """                         dt       p
0 2011-01-01 09:00:00-05:00 2011-01
1 2011-01-01 10:00:00-05:00 2011-02
2 2011-01-01 11:00:00-05:00 2011-03
3 2011-01-01 12:00:00-05:00 2011-04
4 2011-01-01 13:00:00-05:00 2011-05"""

        df = pd.DataFrame({'dt': pd.Categorical(dt), 'p': pd.Categorical(p)})
        self.assertEqual(repr(df), exp)

    def test_info(self):

        # make sure it works
        n = 2500
        df = DataFrame({'int64': np.random.randint(100, size=n)})
        df['category'] = Series(np.array(list('abcdefghij')).take(
            np.random.randint(0, 10, size=n))).astype('category')
        df.isnull()
        df.info()

        df2 = df[df['category'] == 'd']
        df2.info()

    def test_groupby_sort(self):

        # http://stackoverflow.com/questions/23814368/sorting-pandas-categorical-labels-after-groupby
        # This should result in a properly sorted Series so that the plot
        # has a sorted x axis
        # self.cat.groupby(['value_group'])['value_group'].count().plot(kind='bar')

        res = self.cat.groupby(['value_group'])['value_group'].count()
        exp = res[sorted(res.index, key=lambda x: float(x.split()[0]))]
        exp.index = pd.CategoricalIndex(exp.index, name=exp.index.name)
        tm.assert_series_equal(res, exp)

    def test_min_max(self):
        # unordered cats have no min/max
        cat = Series(Categorical(["a", "b", "c", "d"], ordered=False))
        self.assertRaises(TypeError, lambda: cat.min())
        self.assertRaises(TypeError, lambda: cat.max())

        cat = Series(Categorical(["a", "b", "c", "d"], ordered=True))
        _min = cat.min()
        _max = cat.max()
        self.assertEqual(_min, "a")
        self.assertEqual(_max, "d")

        cat = Series(Categorical(["a", "b", "c", "d"], categories=[
                     'd', 'c', 'b', 'a'], ordered=True))
        _min = cat.min()
        _max = cat.max()
        self.assertEqual(_min, "d")
        self.assertEqual(_max, "a")

        cat = Series(Categorical(
            [np.nan, "b", "c", np.nan], categories=['d', 'c', 'b', 'a'
                                                    ], ordered=True))
        _min = cat.min()
        _max = cat.max()
        self.assertTrue(np.isnan(_min))
        self.assertEqual(_max, "b")

        cat = Series(Categorical(
            [np.nan, 1, 2, np.nan], categories=[5, 4, 3, 2, 1], ordered=True))
        _min = cat.min()
        _max = cat.max()
        self.assertTrue(np.isnan(_min))
        self.assertEqual(_max, 1)

    def test_mode(self):
        s = Series(Categorical([1, 1, 2, 4, 5, 5, 5],
                               categories=[5, 4, 3, 2, 1], ordered=True))
        res = s.mode()
        exp = Series(Categorical([5], categories=[
                     5, 4, 3, 2, 1], ordered=True))
        tm.assert_series_equal(res, exp)
        s = Series(Categorical([1, 1, 1, 4, 5, 5, 5],
                               categories=[5, 4, 3, 2, 1], ordered=True))
        res = s.mode()
        exp = Series(Categorical([5, 1], categories=[
                     5, 4, 3, 2, 1], ordered=True))
        tm.assert_series_equal(res, exp)
        s = Series(Categorical([1, 2, 3, 4, 5], categories=[5, 4, 3, 2, 1],
                               ordered=True))
        res = s.mode()
        exp = Series(Categorical([], categories=[5, 4, 3, 2, 1], ordered=True))
        tm.assert_series_equal(res, exp)

    def test_value_counts(self):
        # GH 12835
        cats = pd.Categorical(["a", "b", "c", "c", "c", "b"],
                              categories=["c", "a", "b", "d"])
        s = pd.Series(cats, name='xxx')
        res = s.value_counts(sort=False)

        exp_index = pd.CategoricalIndex(["c", "a", "b", "d"],
                                        categories=cats.categories)
        exp = Series([3, 1, 2, 0], name='xxx', index=exp_index)
        tm.assert_series_equal(res, exp)

        res = s.value_counts(sort=True)

        exp_index = pd.CategoricalIndex(["c", "b", "a", "d"],
                                        categories=cats.categories)
        exp = Series([3, 2, 1, 0], name='xxx', index=exp_index)
        tm.assert_series_equal(res, exp)

        # check object dtype handles the Series.name as the same
        # (tested in test_base.py)
        s = pd.Series(["a", "b", "c", "c", "c", "b"], name='xxx')
        res = s.value_counts()
        exp = Series([3, 2, 1], name='xxx', index=["c", "b", "a"])
        tm.assert_series_equal(res, exp)

    def test_value_counts_with_nan(self):
        # https://github.com/pydata/pandas/issues/9443

        s = pd.Series(["a", "b", "a"], dtype="category")
        tm.assert_series_equal(
            s.value_counts(dropna=True),
            pd.Series([2, 1], index=pd.CategoricalIndex(["a", "b"])))
        tm.assert_series_equal(
            s.value_counts(dropna=False),
            pd.Series([2, 1], index=pd.CategoricalIndex(["a", "b"])))

        s = pd.Series(["a", "b", None, "a", None, None], dtype="category")
        tm.assert_series_equal(
            s.value_counts(dropna=True),
            pd.Series([2, 1], index=pd.CategoricalIndex(["a", "b"])))
        tm.assert_series_equal(
            s.value_counts(dropna=False),
            pd.Series([3, 2, 1], index=pd.CategoricalIndex([np.nan, "a", "b"])))
        # When we aren't sorting by counts, and np.nan isn't a
        # category, it should be last.
        tm.assert_series_equal(
            s.value_counts(dropna=False, sort=False),
            pd.Series([2, 1, 3],
                      index=pd.CategoricalIndex(["a", "b", np.nan])))

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            s = pd.Series(pd.Categorical(["a", "b", "a"],
                                         categories=["a", "b", np.nan]))

        # internal categories are different because of NaN
        exp = pd.Series([2, 1], index=pd.CategoricalIndex(["a", "b"]))
        tm.assert_series_equal(s.value_counts(dropna=True), exp,
                               check_categorical=False)
        exp = pd.Series([2, 1, 0],
                        index=pd.CategoricalIndex(["a", "b", np.nan]))
        tm.assert_series_equal(s.value_counts(dropna=False), exp,
                               check_categorical=False)

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            s = pd.Series(pd.Categorical(["a", "b", None, "a", None, None],
                                         categories=["a", "b", np.nan]))

        exp = pd.Series([2, 1], index=pd.CategoricalIndex(["a", "b"]))
        tm.assert_series_equal(s.value_counts(dropna=True), exp,
                               check_categorical=False)
        exp = pd.Series([3, 2, 1],
                        index=pd.CategoricalIndex([np.nan, "a", "b"]))
        tm.assert_series_equal(s.value_counts(dropna=False), exp,
                               check_categorical=False)

    def test_groupby(self):

        cats = Categorical(["a", "a", "a", "b", "b", "b", "c", "c", "c"],
                           categories=["a", "b", "c", "d"], ordered=True)
        data = DataFrame({"a": [1, 1, 1, 2, 2, 2, 3, 4, 5], "b": cats})

        exp_index = pd.CategoricalIndex(['a', 'b', 'c', 'd'], name='b',
                                        ordered=True)
        expected = DataFrame({'a': [1, 2, 4, np.nan]}, index=exp_index)
        result = data.groupby("b").mean()
        tm.assert_frame_equal(result, expected)

        raw_cat1 = Categorical(["a", "a", "b", "b"],
                               categories=["a", "b", "z"], ordered=True)
        raw_cat2 = Categorical(["c", "d", "c", "d"],
                               categories=["c", "d", "y"], ordered=True)
        df = DataFrame({"A": raw_cat1, "B": raw_cat2, "values": [1, 2, 3, 4]})

        # single grouper
        gb = df.groupby("A")
        exp_idx = pd.CategoricalIndex(['a', 'b', 'z'], name='A', ordered=True)
        expected = DataFrame({'values': Series([3, 7, np.nan], index=exp_idx)})
        result = gb.sum()
        tm.assert_frame_equal(result, expected)

        # multiple groupers
        gb = df.groupby(['A', 'B'])
        exp_index = pd.MultiIndex.from_product([['a', 'b', 'z'],
                                                ['c', 'd', 'y']],
                                               names=['A', 'B'])
        expected = DataFrame({'values': [1, 2, np.nan, 3, 4, np.nan,
                                         np.nan, np.nan, np.nan]},
                             index=exp_index)
        result = gb.sum()
        tm.assert_frame_equal(result, expected)

        # multiple groupers with a non-cat
        df = df.copy()
        df['C'] = ['foo', 'bar'] * 2
        gb = df.groupby(['A', 'B', 'C'])
        expected = DataFrame({'values': Series(
            np.nan, index=pd.MultiIndex.from_product(
                [['a', 'b', 'z'], ['c', 'd', 'y'], ['foo', 'bar']
                 ], names=['A', 'B', 'C']))}).sortlevel()
        expected.iloc[[1, 2, 7, 8], 0] = [1, 2, 3, 4]
        result = gb.sum()
        tm.assert_frame_equal(result, expected)

        # GH 8623
        x = pd.DataFrame([[1, 'John P. Doe'], [2, 'Jane Dove'],
                          [1, 'John P. Doe']],
                         columns=['person_id', 'person_name'])
        x['person_name'] = pd.Categorical(x.person_name)

        g = x.groupby(['person_id'])
        result = g.transform(lambda x: x)
        tm.assert_frame_equal(result, x[['person_name']])

        result = x.drop_duplicates('person_name')
        expected = x.iloc[[0, 1]]
        tm.assert_frame_equal(result, expected)

        def f(x):
            return x.drop_duplicates('person_name').iloc[0]

        result = g.apply(f)
        expected = x.iloc[[0, 1]].copy()
        expected.index = Index([1, 2], name='person_id')
        expected['person_name'] = expected['person_name'].astype('object')
        tm.assert_frame_equal(result, expected)

        # GH 9921
        # Monotonic
        df = DataFrame({"a": [5, 15, 25]})
        c = pd.cut(df.a, bins=[0, 10, 20, 30, 40])

        result = df.a.groupby(c).transform(sum)
        tm.assert_series_equal(result, df['a'])

        tm.assert_series_equal(
            df.a.groupby(c).transform(lambda xs: np.sum(xs)), df['a'])
        tm.assert_frame_equal(df.groupby(c).transform(sum), df[['a']])
        tm.assert_frame_equal(
            df.groupby(c).transform(lambda xs: np.max(xs)), df[['a']])

        # Filter
        tm.assert_series_equal(df.a.groupby(c).filter(np.all), df['a'])
        tm.assert_frame_equal(df.groupby(c).filter(np.all), df)

        # Non-monotonic
        df = DataFrame({"a": [5, 15, 25, -5]})
        c = pd.cut(df.a, bins=[-10, 0, 10, 20, 30, 40])

        result = df.a.groupby(c).transform(sum)
        tm.assert_series_equal(result, df['a'])

        tm.assert_series_equal(
            df.a.groupby(c).transform(lambda xs: np.sum(xs)), df['a'])
        tm.assert_frame_equal(df.groupby(c).transform(sum), df[['a']])
        tm.assert_frame_equal(
            df.groupby(c).transform(lambda xs: np.sum(xs)), df[['a']])

        # GH 9603
        df = pd.DataFrame({'a': [1, 0, 0, 0]})
        c = pd.cut(df.a, [0, 1, 2, 3, 4])
        result = df.groupby(c).apply(len)

        exp_index = pd.CategoricalIndex(c.values.categories,
                                        ordered=c.values.ordered)
        expected = pd.Series([1, 0, 0, 0], index=exp_index)
        expected.index.name = 'a'
        tm.assert_series_equal(result, expected)

    def test_pivot_table(self):

        raw_cat1 = Categorical(["a", "a", "b", "b"],
                               categories=["a", "b", "z"], ordered=True)
        raw_cat2 = Categorical(["c", "d", "c", "d"],
                               categories=["c", "d", "y"], ordered=True)
        df = DataFrame({"A": raw_cat1, "B": raw_cat2, "values": [1, 2, 3, 4]})
        result = pd.pivot_table(df, values='values', index=['A', 'B'])

        expected = Series([1, 2, np.nan, 3, 4, np.nan, np.nan, np.nan, np.nan],
                          index=pd.MultiIndex.from_product(
                              [['a', 'b', 'z'], ['c', 'd', 'y']],
                              names=['A', 'B']),
                          name='values')
        tm.assert_series_equal(result, expected)

    def test_count(self):

        s = Series(Categorical([np.nan, 1, 2, np.nan],
                               categories=[5, 4, 3, 2, 1], ordered=True))
        result = s.count()
        self.assertEqual(result, 2)

    def test_sort_values(self):

        c = Categorical(["a", "b", "b", "a"], ordered=False)
        cat = Series(c.copy())

        # 'order' was deprecated in gh-10726
        # 'sort' was deprecated in gh-12882
        for func in ('order', 'sort'):
            with tm.assert_produces_warning(FutureWarning):
                getattr(c, func)()

        # sort in the categories order
        expected = Series(
            Categorical(["a", "a", "b", "b"],
                        ordered=False), index=[0, 3, 1, 2])
        result = cat.sort_values()
        tm.assert_series_equal(result, expected)

        cat = Series(Categorical(["a", "c", "b", "d"], ordered=True))
        res = cat.sort_values()
        exp = np.array(["a", "b", "c", "d"], dtype=np.object_)
        self.assert_numpy_array_equal(res.__array__(), exp)

        cat = Series(Categorical(["a", "c", "b", "d"], categories=[
                     "a", "b", "c", "d"], ordered=True))
        res = cat.sort_values()
        exp = np.array(["a", "b", "c", "d"], dtype=np.object_)
        self.assert_numpy_array_equal(res.__array__(), exp)

        res = cat.sort_values(ascending=False)
        exp = np.array(["d", "c", "b", "a"], dtype=np.object_)
        self.assert_numpy_array_equal(res.__array__(), exp)

        raw_cat1 = Categorical(["a", "b", "c", "d"],
                               categories=["a", "b", "c", "d"], ordered=False)
        raw_cat2 = Categorical(["a", "b", "c", "d"],
                               categories=["d", "c", "b", "a"], ordered=True)
        s = ["a", "b", "c", "d"]
        df = DataFrame({"unsort": raw_cat1,
                        "sort": raw_cat2,
                        "string": s,
                        "values": [1, 2, 3, 4]})

        # Cats must be sorted in a dataframe
        res = df.sort_values(by=["string"], ascending=False)
        exp = np.array(["d", "c", "b", "a"], dtype=np.object_)
        self.assert_numpy_array_equal(res["sort"].values.__array__(), exp)
        self.assertEqual(res["sort"].dtype, "category")

        res = df.sort_values(by=["sort"], ascending=False)
        exp = df.sort_values(by=["string"], ascending=True)
        self.assert_series_equal(res["values"], exp["values"])
        self.assertEqual(res["sort"].dtype, "category")
        self.assertEqual(res["unsort"].dtype, "category")

        # unordered cat, but we allow this
        df.sort_values(by=["unsort"], ascending=False)

        # multi-columns sort
        # GH 7848
        df = DataFrame({"id": [6, 5, 4, 3, 2, 1],
                        "raw_grade": ['a', 'b', 'b', 'a', 'a', 'e']})
        df["grade"] = pd.Categorical(df["raw_grade"], ordered=True)
        df['grade'] = df['grade'].cat.set_categories(['b', 'e', 'a'])

        # sorts 'grade' according to the order of the categories
        result = df.sort_values(by=['grade'])
        expected = df.iloc[[1, 2, 5, 0, 3, 4]]
        tm.assert_frame_equal(result, expected)

        # multi
        result = df.sort_values(by=['grade', 'id'])
        expected = df.iloc[[2, 1, 5, 4, 3, 0]]
        tm.assert_frame_equal(result, expected)

    def test_slicing(self):
        cat = Series(Categorical([1, 2, 3, 4]))
        reversed = cat[::-1]
        exp = np.array([4, 3, 2, 1], dtype=np.int64)
        self.assert_numpy_array_equal(reversed.__array__(), exp)

        df = DataFrame({'value': (np.arange(100) + 1).astype('int64')})
        df['D'] = pd.cut(df.value, bins=[0, 25, 50, 75, 100])

        expected = Series([11, '(0, 25]'], index=['value', 'D'], name=10)
        result = df.iloc[10]
        tm.assert_series_equal(result, expected)

        expected = DataFrame({'value': np.arange(11, 21).astype('int64')},
                             index=np.arange(10, 20).astype('int64'))
        expected['D'] = pd.cut(expected.value, bins=[0, 25, 50, 75, 100])
        result = df.iloc[10:20]
        tm.assert_frame_equal(result, expected)

        expected = Series([9, '(0, 25]'], index=['value', 'D'], name=8)
        result = df.loc[8]
        tm.assert_series_equal(result, expected)

    def test_slicing_and_getting_ops(self):

        # systematically test the slicing operations:
        #  for all slicing ops:
        #   - returning a dataframe
        #   - returning a column
        #   - returning a row
        #   - returning a single value

        cats = pd.Categorical(
            ["a", "c", "b", "c", "c", "c", "c"], categories=["a", "b", "c"])
        idx = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values = [1, 2, 3, 4, 5, 6, 7]
        df = pd.DataFrame({"cats": cats, "values": values}, index=idx)

        # the expected values
        cats2 = pd.Categorical(["b", "c"], categories=["a", "b", "c"])
        idx2 = pd.Index(["j", "k"])
        values2 = [3, 4]

        # 2:4,: | "j":"k",:
        exp_df = pd.DataFrame({"cats": cats2, "values": values2}, index=idx2)

        # :,"cats" | :,0
        exp_col = pd.Series(cats, index=idx, name='cats')

        # "j",: | 2,:
        exp_row = pd.Series(["b", 3], index=["cats", "values"], dtype="object",
                            name="j")

        # "j","cats | 2,0
        exp_val = "b"

        # iloc
        # frame
        res_df = df.iloc[2:4, :]
        tm.assert_frame_equal(res_df, exp_df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        # row
        res_row = df.iloc[2, :]
        tm.assert_series_equal(res_row, exp_row)
        tm.assertIsInstance(res_row["cats"], compat.string_types)

        # col
        res_col = df.iloc[:, 0]
        tm.assert_series_equal(res_col, exp_col)
        self.assertTrue(is_categorical_dtype(res_col))

        # single value
        res_val = df.iloc[2, 0]
        self.assertEqual(res_val, exp_val)

        # loc
        # frame
        res_df = df.loc["j":"k", :]
        tm.assert_frame_equal(res_df, exp_df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        # row
        res_row = df.loc["j", :]
        tm.assert_series_equal(res_row, exp_row)
        tm.assertIsInstance(res_row["cats"], compat.string_types)

        # col
        res_col = df.loc[:, "cats"]
        tm.assert_series_equal(res_col, exp_col)
        self.assertTrue(is_categorical_dtype(res_col))

        # single value
        res_val = df.loc["j", "cats"]
        self.assertEqual(res_val, exp_val)

        # ix
        # frame
        # res_df = df.ix["j":"k",[0,1]] # doesn't work?
        res_df = df.ix["j":"k", :]
        tm.assert_frame_equal(res_df, exp_df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        # row
        res_row = df.ix["j", :]
        tm.assert_series_equal(res_row, exp_row)
        tm.assertIsInstance(res_row["cats"], compat.string_types)

        # col
        res_col = df.ix[:, "cats"]
        tm.assert_series_equal(res_col, exp_col)
        self.assertTrue(is_categorical_dtype(res_col))

        # single value
        res_val = df.ix["j", 0]
        self.assertEqual(res_val, exp_val)

        # iat
        res_val = df.iat[2, 0]
        self.assertEqual(res_val, exp_val)

        # at
        res_val = df.at["j", "cats"]
        self.assertEqual(res_val, exp_val)

        # fancy indexing
        exp_fancy = df.iloc[[2]]

        res_fancy = df[df["cats"] == "b"]
        tm.assert_frame_equal(res_fancy, exp_fancy)
        res_fancy = df[df["values"] == 3]
        tm.assert_frame_equal(res_fancy, exp_fancy)

        # get_value
        res_val = df.get_value("j", "cats")
        self.assertEqual(res_val, exp_val)

        # i : int, slice, or sequence of integers
        res_row = df.iloc[2]
        tm.assert_series_equal(res_row, exp_row)
        tm.assertIsInstance(res_row["cats"], compat.string_types)

        res_df = df.iloc[slice(2, 4)]
        tm.assert_frame_equal(res_df, exp_df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        res_df = df.iloc[[2, 3]]
        tm.assert_frame_equal(res_df, exp_df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        res_col = df.iloc[:, 0]
        tm.assert_series_equal(res_col, exp_col)
        self.assertTrue(is_categorical_dtype(res_col))

        res_df = df.iloc[:, slice(0, 2)]
        tm.assert_frame_equal(res_df, df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

        res_df = df.iloc[:, [0, 1]]
        tm.assert_frame_equal(res_df, df)
        self.assertTrue(is_categorical_dtype(res_df["cats"]))

    def test_slicing_doc_examples(self):

        # GH 7918
        cats = Categorical(
            ["a", "b", "b", "b", "c", "c", "c"], categories=["a", "b", "c"])
        idx = Index(["h", "i", "j", "k", "l", "m", "n", ])
        values = [1, 2, 2, 2, 3, 4, 5]
        df = DataFrame({"cats": cats, "values": values}, index=idx)

        result = df.iloc[2:4, :]
        expected = DataFrame(
            {"cats": Categorical(
                ['b', 'b'], categories=['a', 'b', 'c']),
             "values": [2, 2]}, index=['j', 'k'])
        tm.assert_frame_equal(result, expected)

        result = df.iloc[2:4, :].dtypes
        expected = Series(['category', 'int64'], ['cats', 'values'])
        tm.assert_series_equal(result, expected)

        result = df.loc["h":"j", "cats"]
        expected = Series(Categorical(['a', 'b', 'b'],
                                      categories=['a', 'b', 'c']),
                          index=['h', 'i', 'j'], name='cats')
        tm.assert_series_equal(result, expected)

        result = df.ix["h":"j", 0:1]
        expected = DataFrame({'cats': Series(
            Categorical(
                ['a', 'b', 'b'], categories=['a', 'b', 'c']), index=['h', 'i',
                                                                     'j'])})
        tm.assert_frame_equal(result, expected)

    def test_assigning_ops(self):
        # systematically test the assigning operations:
        # for all slicing ops:
        #  for value in categories and value not in categories:

        #   - assign a single value -> exp_single_cats_value

        #   - assign a complete row (mixed values) -> exp_single_row

        # assign multiple rows (mixed values) (-> array) -> exp_multi_row

        # assign a part of a column with dtype == categorical ->
        # exp_parts_cats_col

        # assign a part of a column with dtype != categorical ->
        # exp_parts_cats_col

        cats = pd.Categorical(["a", "a", "a", "a", "a", "a", "a"],
                              categories=["a", "b"])
        idx = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values = [1, 1, 1, 1, 1, 1, 1]
        orig = pd.DataFrame({"cats": cats, "values": values}, index=idx)

        # the expected values
        # changed single row
        cats1 = pd.Categorical(["a", "a", "b", "a", "a", "a", "a"],
                               categories=["a", "b"])
        idx1 = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values1 = [1, 1, 2, 1, 1, 1, 1]
        exp_single_row = pd.DataFrame({"cats": cats1,
                                       "values": values1}, index=idx1)

        # changed multiple rows
        cats2 = pd.Categorical(["a", "a", "b", "b", "a", "a", "a"],
                               categories=["a", "b"])
        idx2 = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values2 = [1, 1, 2, 2, 1, 1, 1]
        exp_multi_row = pd.DataFrame({"cats": cats2,
                                      "values": values2}, index=idx2)

        # changed part of the cats column
        cats3 = pd.Categorical(
            ["a", "a", "b", "b", "a", "a", "a"], categories=["a", "b"])
        idx3 = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values3 = [1, 1, 1, 1, 1, 1, 1]
        exp_parts_cats_col = pd.DataFrame(
            {"cats": cats3,
             "values": values3}, index=idx3)

        # changed single value in cats col
        cats4 = pd.Categorical(
            ["a", "a", "b", "a", "a", "a", "a"], categories=["a", "b"])
        idx4 = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        values4 = [1, 1, 1, 1, 1, 1, 1]
        exp_single_cats_value = pd.DataFrame(
            {"cats": cats4,
             "values": values4}, index=idx4)

        #  iloc
        # ###############
        #   - assign a single value -> exp_single_cats_value
        df = orig.copy()
        df.iloc[2, 0] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        df = orig.copy()
        df.iloc[df.index == "j", 0] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        #   - assign a single value not in the current categories set
        def f():
            df = orig.copy()
            df.iloc[2, 0] = "c"

        self.assertRaises(ValueError, f)

        #   - assign a complete row (mixed values) -> exp_single_row
        df = orig.copy()
        df.iloc[2, :] = ["b", 2]
        tm.assert_frame_equal(df, exp_single_row)

        #   - assign a complete row (mixed values) not in categories set
        def f():
            df = orig.copy()
            df.iloc[2, :] = ["c", 2]

        self.assertRaises(ValueError, f)

        #   - assign multiple rows (mixed values) -> exp_multi_row
        df = orig.copy()
        df.iloc[2:4, :] = [["b", 2], ["b", 2]]
        tm.assert_frame_equal(df, exp_multi_row)

        def f():
            df = orig.copy()
            df.iloc[2:4, :] = [["c", 2], ["c", 2]]

        self.assertRaises(ValueError, f)

        # assign a part of a column with dtype == categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.iloc[2:4, 0] = pd.Categorical(["b", "b"], categories=["a", "b"])
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            # different categories -> not sure if this should fail or pass
            df = orig.copy()
            df.iloc[2:4, 0] = pd.Categorical(
                ["b", "b"], categories=["a", "b", "c"])

        with tm.assertRaises(ValueError):
            # different values
            df = orig.copy()
            df.iloc[2:4, 0] = pd.Categorical(
                ["c", "c"], categories=["a", "b", "c"])

        # assign a part of a column with dtype != categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.iloc[2:4, 0] = ["b", "b"]
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            df.iloc[2:4, 0] = ["c", "c"]

        #  loc
        # ##############
        #   - assign a single value -> exp_single_cats_value
        df = orig.copy()
        df.loc["j", "cats"] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        df = orig.copy()
        df.loc[df.index == "j", "cats"] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        #   - assign a single value not in the current categories set
        def f():
            df = orig.copy()
            df.loc["j", "cats"] = "c"

        self.assertRaises(ValueError, f)

        #   - assign a complete row (mixed values) -> exp_single_row
        df = orig.copy()
        df.loc["j", :] = ["b", 2]
        tm.assert_frame_equal(df, exp_single_row)

        #   - assign a complete row (mixed values) not in categories set
        def f():
            df = orig.copy()
            df.loc["j", :] = ["c", 2]

        self.assertRaises(ValueError, f)

        #   - assign multiple rows (mixed values) -> exp_multi_row
        df = orig.copy()
        df.loc["j":"k", :] = [["b", 2], ["b", 2]]
        tm.assert_frame_equal(df, exp_multi_row)

        def f():
            df = orig.copy()
            df.loc["j":"k", :] = [["c", 2], ["c", 2]]

        self.assertRaises(ValueError, f)

        # assign a part of a column with dtype == categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.loc["j":"k", "cats"] = pd.Categorical(
            ["b", "b"], categories=["a", "b"])
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            # different categories -> not sure if this should fail or pass
            df = orig.copy()
            df.loc["j":"k", "cats"] = pd.Categorical(
                ["b", "b"], categories=["a", "b", "c"])

        with tm.assertRaises(ValueError):
            # different values
            df = orig.copy()
            df.loc["j":"k", "cats"] = pd.Categorical(
                ["c", "c"], categories=["a", "b", "c"])

        # assign a part of a column with dtype != categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.loc["j":"k", "cats"] = ["b", "b"]
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            df.loc["j":"k", "cats"] = ["c", "c"]

        #  ix
        # ##############
        #   - assign a single value -> exp_single_cats_value
        df = orig.copy()
        df.ix["j", 0] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        df = orig.copy()
        df.ix[df.index == "j", 0] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        #   - assign a single value not in the current categories set
        def f():
            df = orig.copy()
            df.ix["j", 0] = "c"

        self.assertRaises(ValueError, f)

        #   - assign a complete row (mixed values) -> exp_single_row
        df = orig.copy()
        df.ix["j", :] = ["b", 2]
        tm.assert_frame_equal(df, exp_single_row)

        #   - assign a complete row (mixed values) not in categories set
        def f():
            df = orig.copy()
            df.ix["j", :] = ["c", 2]

        self.assertRaises(ValueError, f)

        #   - assign multiple rows (mixed values) -> exp_multi_row
        df = orig.copy()
        df.ix["j":"k", :] = [["b", 2], ["b", 2]]
        tm.assert_frame_equal(df, exp_multi_row)

        def f():
            df = orig.copy()
            df.ix["j":"k", :] = [["c", 2], ["c", 2]]

        self.assertRaises(ValueError, f)

        # assign a part of a column with dtype == categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.ix["j":"k", 0] = pd.Categorical(["b", "b"], categories=["a", "b"])
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            # different categories -> not sure if this should fail or pass
            df = orig.copy()
            df.ix["j":"k", 0] = pd.Categorical(
                ["b", "b"], categories=["a", "b", "c"])

        with tm.assertRaises(ValueError):
            # different values
            df = orig.copy()
            df.ix["j":"k", 0] = pd.Categorical(
                ["c", "c"], categories=["a", "b", "c"])

        # assign a part of a column with dtype != categorical ->
        # exp_parts_cats_col
        df = orig.copy()
        df.ix["j":"k", 0] = ["b", "b"]
        tm.assert_frame_equal(df, exp_parts_cats_col)

        with tm.assertRaises(ValueError):
            df.ix["j":"k", 0] = ["c", "c"]

        # iat
        df = orig.copy()
        df.iat[2, 0] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        #   - assign a single value not in the current categories set
        def f():
            df = orig.copy()
            df.iat[2, 0] = "c"

        self.assertRaises(ValueError, f)

        # at
        #   - assign a single value -> exp_single_cats_value
        df = orig.copy()
        df.at["j", "cats"] = "b"
        tm.assert_frame_equal(df, exp_single_cats_value)

        #   - assign a single value not in the current categories set
        def f():
            df = orig.copy()
            df.at["j", "cats"] = "c"

        self.assertRaises(ValueError, f)

        # fancy indexing
        catsf = pd.Categorical(
            ["a", "a", "c", "c", "a", "a", "a"], categories=["a", "b", "c"])
        idxf = pd.Index(["h", "i", "j", "k", "l", "m", "n"])
        valuesf = [1, 1, 3, 3, 1, 1, 1]
        df = pd.DataFrame({"cats": catsf, "values": valuesf}, index=idxf)

        exp_fancy = exp_multi_row.copy()
        exp_fancy["cats"].cat.set_categories(["a", "b", "c"], inplace=True)

        df[df["cats"] == "c"] = ["b", 2]
        # category c is kept in .categories
        tm.assert_frame_equal(df, exp_fancy)

        # set_value
        df = orig.copy()
        df.set_value("j", "cats", "b")
        tm.assert_frame_equal(df, exp_single_cats_value)

        def f():
            df = orig.copy()
            df.set_value("j", "cats", "c")

        self.assertRaises(ValueError, f)

        # Assigning a Category to parts of a int/... column uses the values of
        # the Catgorical
        df = pd.DataFrame({"a": [1, 1, 1, 1, 1],
                           "b": ["a", "a", "a", "a", "a"]})
        exp = pd.DataFrame({"a": [1, "b", "b", 1, 1],
                            "b": ["a", "a", "b", "b", "a"]})
        df.loc[1:2, "a"] = pd.Categorical(["b", "b"], categories=["a", "b"])
        df.loc[2:3, "b"] = pd.Categorical(["b", "b"], categories=["a", "b"])
        tm.assert_frame_equal(df, exp)

        # Series
        orig = Series(pd.Categorical(["b", "b"], categories=["a", "b"]))
        s = orig.copy()
        s[:] = "a"
        exp = Series(pd.Categorical(["a", "a"], categories=["a", "b"]))
        tm.assert_series_equal(s, exp)

        s = orig.copy()
        s[1] = "a"
        exp = Series(pd.Categorical(["b", "a"], categories=["a", "b"]))
        tm.assert_series_equal(s, exp)

        s = orig.copy()
        s[s.index > 0] = "a"
        exp = Series(pd.Categorical(["b", "a"], categories=["a", "b"]))
        tm.assert_series_equal(s, exp)

        s = orig.copy()
        s[[False, True]] = "a"
        exp = Series(pd.Categorical(["b", "a"], categories=["a", "b"]))
        tm.assert_series_equal(s, exp)

        s = orig.copy()
        s.index = ["x", "y"]
        s["y"] = "a"
        exp = Series(
            pd.Categorical(["b", "a"],
                           categories=["a", "b"]), index=["x", "y"])
        tm.assert_series_equal(s, exp)

        # ensure that one can set something to np.nan
        s = Series(Categorical([1, 2, 3]))
        exp = Series(Categorical([1, np.nan, 3], categories=[1, 2, 3]))
        s[1] = np.nan
        tm.assert_series_equal(s, exp)

    def test_comparisons(self):
        tests_data = [(list("abc"), list("cba"), list("bbb")),
                      ([1, 2, 3], [3, 2, 1], [2, 2, 2])]
        for data, reverse, base in tests_data:
            cat_rev = pd.Series(pd.Categorical(data, categories=reverse,
                                               ordered=True))
            cat_rev_base = pd.Series(pd.Categorical(base, categories=reverse,
                                                    ordered=True))
            cat = pd.Series(pd.Categorical(data, ordered=True))
            cat_base = pd.Series(pd.Categorical(
                base, categories=cat.cat.categories, ordered=True))
            s = Series(base)
            a = np.array(base)

            # comparisons need to take categories ordering into account
            res_rev = cat_rev > cat_rev_base
            exp_rev = Series([True, False, False])
            tm.assert_series_equal(res_rev, exp_rev)

            res_rev = cat_rev < cat_rev_base
            exp_rev = Series([False, False, True])
            tm.assert_series_equal(res_rev, exp_rev)

            res = cat > cat_base
            exp = Series([False, False, True])
            tm.assert_series_equal(res, exp)

            scalar = base[1]
            res = cat > scalar
            exp = Series([False, False, True])
            exp2 = cat.values > scalar
            tm.assert_series_equal(res, exp)
            tm.assert_numpy_array_equal(res.values, exp2)
            res_rev = cat_rev > scalar
            exp_rev = Series([True, False, False])
            exp_rev2 = cat_rev.values > scalar
            tm.assert_series_equal(res_rev, exp_rev)
            tm.assert_numpy_array_equal(res_rev.values, exp_rev2)

            # Only categories with same categories can be compared
            def f():
                cat > cat_rev

            self.assertRaises(TypeError, f)

            # categorical cannot be compared to Series or numpy array, and also
            # not the other way around
            self.assertRaises(TypeError, lambda: cat > s)
            self.assertRaises(TypeError, lambda: cat_rev > s)
            self.assertRaises(TypeError, lambda: cat > a)
            self.assertRaises(TypeError, lambda: cat_rev > a)

            self.assertRaises(TypeError, lambda: s < cat)
            self.assertRaises(TypeError, lambda: s < cat_rev)

            self.assertRaises(TypeError, lambda: a < cat)
            self.assertRaises(TypeError, lambda: a < cat_rev)

        # unequal comparison should raise for unordered cats
        cat = Series(Categorical(list("abc")))

        def f():
            cat > "b"

        self.assertRaises(TypeError, f)
        cat = Series(Categorical(list("abc"), ordered=False))

        def f():
            cat > "b"

        self.assertRaises(TypeError, f)

        # https://github.com/pydata/pandas/issues/9836#issuecomment-92123057
        # and following comparisons with scalars not in categories should raise
        # for unequal comps, but not for equal/not equal
        cat = Series(Categorical(list("abc"), ordered=True))

        self.assertRaises(TypeError, lambda: cat < "d")
        self.assertRaises(TypeError, lambda: cat > "d")
        self.assertRaises(TypeError, lambda: "d" < cat)
        self.assertRaises(TypeError, lambda: "d" > cat)

        self.assert_series_equal(cat == "d", Series([False, False, False]))
        self.assert_series_equal(cat != "d", Series([True, True, True]))

        # And test NaN handling...
        cat = Series(Categorical(["a", "b", "c", np.nan]))
        exp = Series([True, True, True, False])
        res = (cat == cat)
        tm.assert_series_equal(res, exp)

    def test_cat_equality(self):

        # GH 8938
        # allow equality comparisons
        a = Series(list('abc'), dtype="category")
        b = Series(list('abc'), dtype="object")
        c = Series(['a', 'b', 'cc'], dtype="object")
        d = Series(list('acb'), dtype="object")
        e = Categorical(list('abc'))
        f = Categorical(list('acb'))

        # vs scalar
        self.assertFalse((a == 'a').all())
        self.assertTrue(((a != 'a') == ~(a == 'a')).all())

        self.assertFalse(('a' == a).all())
        self.assertTrue((a == 'a')[0])
        self.assertTrue(('a' == a)[0])
        self.assertFalse(('a' != a)[0])

        # vs list-like
        self.assertTrue((a == a).all())
        self.assertFalse((a != a).all())

        self.assertTrue((a == list(a)).all())
        self.assertTrue((a == b).all())
        self.assertTrue((b == a).all())
        self.assertTrue(((~(a == b)) == (a != b)).all())
        self.assertTrue(((~(b == a)) == (b != a)).all())

        self.assertFalse((a == c).all())
        self.assertFalse((c == a).all())
        self.assertFalse((a == d).all())
        self.assertFalse((d == a).all())

        # vs a cat-like
        self.assertTrue((a == e).all())
        self.assertTrue((e == a).all())
        self.assertFalse((a == f).all())
        self.assertFalse((f == a).all())

        self.assertTrue(((~(a == e) == (a != e)).all()))
        self.assertTrue(((~(e == a) == (e != a)).all()))
        self.assertTrue(((~(a == f) == (a != f)).all()))
        self.assertTrue(((~(f == a) == (f != a)).all()))

        # non-equality is not comparable
        self.assertRaises(TypeError, lambda: a < b)
        self.assertRaises(TypeError, lambda: b < a)
        self.assertRaises(TypeError, lambda: a > b)
        self.assertRaises(TypeError, lambda: b > a)

    def test_concat(self):
        cat = pd.Categorical(["a", "b"], categories=["a", "b"])
        vals = [1, 2]
        df = pd.DataFrame({"cats": cat, "vals": vals})
        cat2 = pd.Categorical(["a", "b", "a", "b"], categories=["a", "b"])
        vals2 = [1, 2, 1, 2]
        exp = pd.DataFrame({"cats": cat2,
                            "vals": vals2}, index=pd.Index([0, 1, 0, 1]))

        res = pd.concat([df, df])
        tm.assert_frame_equal(exp, res)

        # Concat should raise if the two categoricals do not have the same
        # categories
        cat3 = pd.Categorical(["a", "b"], categories=["a", "b", "c"])
        vals3 = [1, 2]
        df_wrong_categories = pd.DataFrame({"cats": cat3, "vals": vals3})

        def f():
            pd.concat([df, df_wrong_categories])

        self.assertRaises(ValueError, f)

        # GH 7864
        # make sure ordering is preserverd
        df = pd.DataFrame({"id": [1, 2, 3, 4, 5, 6],
                           "raw_grade": ['a', 'b', 'b', 'a', 'a', 'e']})
        df["grade"] = pd.Categorical(df["raw_grade"])
        df['grade'].cat.set_categories(['e', 'a', 'b'])

        df1 = df[0:3]
        df2 = df[3:]

        self.assert_index_equal(df['grade'].cat.categories,
                                df1['grade'].cat.categories)
        self.assert_index_equal(df['grade'].cat.categories,
                                df2['grade'].cat.categories)

        dfx = pd.concat([df1, df2])
        dfx['grade'].cat.categories
        self.assert_index_equal(df['grade'].cat.categories,
                                dfx['grade'].cat.categories)

    def test_concat_preserve(self):

        # GH 8641
        # series concat not preserving category dtype
        s = Series(list('abc'), dtype='category')
        s2 = Series(list('abd'), dtype='category')

        def f():
            pd.concat([s, s2])

        self.assertRaises(ValueError, f)

        result = pd.concat([s, s], ignore_index=True)
        expected = Series(list('abcabc')).astype('category')
        tm.assert_series_equal(result, expected)

        result = pd.concat([s, s])
        expected = Series(
            list('abcabc'), index=[0, 1, 2, 0, 1, 2]).astype('category')
        tm.assert_series_equal(result, expected)

        a = Series(np.arange(6, dtype='int64'))
        b = Series(list('aabbca'))

        df2 = DataFrame({'A': a,
                         'B': b.astype('category', categories=list('cab'))})
        result = pd.concat([df2, df2])
        expected = DataFrame({'A': pd.concat([a, a]),
                              'B': pd.concat([b, b]).astype(
                                  'category', categories=list('cab'))})
        tm.assert_frame_equal(result, expected)

    def test_categorical_index_preserver(self):

        a = Series(np.arange(6, dtype='int64'))
        b = Series(list('aabbca'))

        df2 = DataFrame({'A': a,
                         'B': b.astype('category', categories=list(
                             'cab'))}).set_index('B')
        result = pd.concat([df2, df2])
        expected = DataFrame({'A': pd.concat([a, a]),
                              'B': pd.concat([b, b]).astype(
                                  'category', categories=list(
                                      'cab'))}).set_index('B')
        tm.assert_frame_equal(result, expected)

        # wrong catgories
        df3 = DataFrame({'A': a,
                         'B': b.astype('category', categories=list(
                             'abc'))}).set_index('B')
        self.assertRaises(TypeError, lambda: pd.concat([df2, df3]))

    def test_append(self):
        cat = pd.Categorical(["a", "b"], categories=["a", "b"])
        vals = [1, 2]
        df = pd.DataFrame({"cats": cat, "vals": vals})
        cat2 = pd.Categorical(["a", "b", "a", "b"], categories=["a", "b"])
        vals2 = [1, 2, 1, 2]
        exp = pd.DataFrame({"cats": cat2,
                            "vals": vals2}, index=pd.Index([0, 1, 0, 1]))

        res = df.append(df)
        tm.assert_frame_equal(exp, res)

        # Concat should raise if the two categoricals do not have the same
        # categories
        cat3 = pd.Categorical(["a", "b"], categories=["a", "b", "c"])
        vals3 = [1, 2]
        df_wrong_categories = pd.DataFrame({"cats": cat3, "vals": vals3})

        def f():
            df.append(df_wrong_categories)

        self.assertRaises(ValueError, f)

    def test_merge(self):
        # GH 9426

        right = DataFrame({'c': {0: 'a',
                                 1: 'b',
                                 2: 'c',
                                 3: 'd',
                                 4: 'e'},
                           'd': {0: 'null',
                                 1: 'null',
                                 2: 'null',
                                 3: 'null',
                                 4: 'null'}})
        left = DataFrame({'a': {0: 'f',
                                1: 'f',
                                2: 'f',
                                3: 'f',
                                4: 'f'},
                          'b': {0: 'g',
                                1: 'g',
                                2: 'g',
                                3: 'g',
                                4: 'g'}})
        df = pd.merge(left, right, how='left', left_on='b', right_on='c')

        # object-object
        expected = df.copy()

        # object-cat
        cright = right.copy()
        cright['d'] = cright['d'].astype('category')
        result = pd.merge(left, cright, how='left', left_on='b', right_on='c')
        tm.assert_frame_equal(result, expected)

        # cat-object
        cleft = left.copy()
        cleft['b'] = cleft['b'].astype('category')
        result = pd.merge(cleft, cright, how='left', left_on='b', right_on='c')
        tm.assert_frame_equal(result, expected)

        # cat-cat
        cright = right.copy()
        cright['d'] = cright['d'].astype('category')
        cleft = left.copy()
        cleft['b'] = cleft['b'].astype('category')
        result = pd.merge(cleft, cright, how='left', left_on='b', right_on='c')
        tm.assert_frame_equal(result, expected)

    def test_repeat(self):
        # GH10183
        cat = pd.Categorical(["a", "b"], categories=["a", "b"])
        exp = pd.Categorical(["a", "a", "b", "b"], categories=["a", "b"])
        res = cat.repeat(2)
        self.assert_categorical_equal(res, exp)

    def test_numpy_repeat(self):
        cat = pd.Categorical(["a", "b"], categories=["a", "b"])
        exp = pd.Categorical(["a", "a", "b", "b"], categories=["a", "b"])
        self.assert_categorical_equal(np.repeat(cat, 2), exp)

        msg = "the 'axis' parameter is not supported"
        tm.assertRaisesRegexp(ValueError, msg, np.repeat, cat, 2, axis=1)

    def test_reshape(self):
        cat = pd.Categorical([], categories=["a", "b"])
        tm.assert_produces_warning(FutureWarning, cat.reshape, 0)

        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical([], categories=["a", "b"])
            self.assert_categorical_equal(cat.reshape(0), cat)

        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical([], categories=["a", "b"])
            self.assert_categorical_equal(cat.reshape((5, -1)), cat)

        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical(["a", "b"], categories=["a", "b"])
            self.assert_categorical_equal(cat.reshape(cat.shape), cat)

        with tm.assert_produces_warning(FutureWarning):
            cat = pd.Categorical(["a", "b"], categories=["a", "b"])
            self.assert_categorical_equal(cat.reshape(cat.size), cat)

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            msg = "can only specify one unknown dimension"
            cat = pd.Categorical(["a", "b"], categories=["a", "b"])
            tm.assertRaisesRegexp(ValueError, msg, cat.reshape, (-2, -1))

    def test_numpy_reshape(self):
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            cat = pd.Categorical(["a", "b"], categories=["a", "b"])
            self.assert_categorical_equal(np.reshape(cat, cat.shape), cat)

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            msg = "the 'order' parameter is not supported"
            tm.assertRaisesRegexp(ValueError, msg, np.reshape,
                                  cat, cat.shape, order='F')

    def test_na_actions(self):

        cat = pd.Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        vals = ["a", "b", np.nan, "d"]
        df = pd.DataFrame({"cats": cat, "vals": vals})
        cat2 = pd.Categorical([1, 2, 3, 3], categories=[1, 2, 3])
        vals2 = ["a", "b", "b", "d"]
        df_exp_fill = pd.DataFrame({"cats": cat2, "vals": vals2})
        cat3 = pd.Categorical([1, 2, 3], categories=[1, 2, 3])
        vals3 = ["a", "b", np.nan]
        df_exp_drop_cats = pd.DataFrame({"cats": cat3, "vals": vals3})
        cat4 = pd.Categorical([1, 2], categories=[1, 2, 3])
        vals4 = ["a", "b"]
        df_exp_drop_all = pd.DataFrame({"cats": cat4, "vals": vals4})

        # fillna
        res = df.fillna(value={"cats": 3, "vals": "b"})
        tm.assert_frame_equal(res, df_exp_fill)

        def f():
            df.fillna(value={"cats": 4, "vals": "c"})

        self.assertRaises(ValueError, f)

        res = df.fillna(method='pad')
        tm.assert_frame_equal(res, df_exp_fill)

        res = df.dropna(subset=["cats"])
        tm.assert_frame_equal(res, df_exp_drop_cats)

        res = df.dropna()
        tm.assert_frame_equal(res, df_exp_drop_all)

        # make sure that fillna takes both missing values and NA categories
        # into account
        c = Categorical(["a", "b", np.nan])
        with tm.assert_produces_warning(FutureWarning):
            c.set_categories(["a", "b", np.nan], rename=True, inplace=True)

        c[0] = np.nan
        df = pd.DataFrame({"cats": c, "vals": [1, 2, 3]})

        cat_exp = Categorical(["a", "b", "a"], categories=["a", "b", np.nan])
        df_exp = pd.DataFrame({"cats": cat_exp, "vals": [1, 2, 3]})

        res = df.fillna("a")
        tm.assert_frame_equal(res, df_exp)

    def test_astype_to_other(self):

        s = self.cat['value_group']
        expected = s
        tm.assert_series_equal(s.astype('category'), expected)
        tm.assert_series_equal(s.astype(CategoricalDtype()), expected)
        self.assertRaises(ValueError, lambda: s.astype('float64'))

        cat = Series(Categorical(['a', 'b', 'b', 'a', 'a', 'c', 'c', 'c']))
        exp = Series(['a', 'b', 'b', 'a', 'a', 'c', 'c', 'c'])
        tm.assert_series_equal(cat.astype('str'), exp)
        s2 = Series(Categorical.from_array(['1', '2', '3', '4']))
        exp2 = Series([1, 2, 3, 4]).astype(int)
        tm.assert_series_equal(s2.astype('int'), exp2)

        # object don't sort correctly, so just compare that we have the same
        # values
        def cmp(a, b):
            tm.assert_almost_equal(
                np.sort(np.unique(a)), np.sort(np.unique(b)))

        expected = Series(np.array(s.values), name='value_group')
        cmp(s.astype('object'), expected)
        cmp(s.astype(np.object_), expected)

        # array conversion
        tm.assert_almost_equal(np.array(s), np.array(s.values))

        # valid conversion
        for valid in [lambda x: x.astype('category'),
                      lambda x: x.astype(CategoricalDtype()),
                      lambda x: x.astype('object').astype('category'),
                      lambda x: x.astype('object').astype(
                          CategoricalDtype())
                      ]:

            result = valid(s)
            # compare series values
            # internal .categories can't be compared because it is sorted
            tm.assert_series_equal(result, s, check_categorical=False)

        # invalid conversion (these are NOT a dtype)
        for invalid in [lambda x: x.astype(pd.Categorical),
                        lambda x: x.astype('object').astype(pd.Categorical)]:
            self.assertRaises(TypeError, lambda: invalid(s))

    def test_astype_categorical(self):

        cat = Categorical(['a', 'b', 'b', 'a', 'a', 'c', 'c', 'c'])
        tm.assert_categorical_equal(cat, cat.astype('category'))
        tm.assert_almost_equal(np.array(cat), cat.astype('object'))

        self.assertRaises(ValueError, lambda: cat.astype(float))

    def test_to_records(self):

        # GH8626

        # dict creation
        df = DataFrame({'A': list('abc')}, dtype='category')
        expected = Series(list('abc'), dtype='category', name='A')
        tm.assert_series_equal(df['A'], expected)

        # list-like creation
        df = DataFrame(list('abc'), dtype='category')
        expected = Series(list('abc'), dtype='category', name=0)
        tm.assert_series_equal(df[0], expected)

        # to record array
        # this coerces
        result = df.to_records()
        expected = np.rec.array([(0, 'a'), (1, 'b'), (2, 'c')],
                                dtype=[('index', '=i8'), ('0', 'O')])
        tm.assert_almost_equal(result, expected)

    def test_numeric_like_ops(self):

        # numeric ops should not succeed
        for op in ['__add__', '__sub__', '__mul__', '__truediv__']:
            self.assertRaises(TypeError,
                              lambda: getattr(self.cat, op)(self.cat))

        # reduction ops should not succeed (unless specifically defined, e.g.
        # min/max)
        s = self.cat['value_group']
        for op in ['kurt', 'skew', 'var', 'std', 'mean', 'sum', 'median']:
            self.assertRaises(TypeError,
                              lambda: getattr(s, op)(numeric_only=False))

        # mad technically works because it takes always the numeric data

        # numpy ops
        s = pd.Series(pd.Categorical([1, 2, 3, 4]))
        self.assertRaises(TypeError, lambda: np.sum(s))

        # numeric ops on a Series
        for op in ['__add__', '__sub__', '__mul__', '__truediv__']:
            self.assertRaises(TypeError, lambda: getattr(s, op)(2))

        # invalid ufunc
        self.assertRaises(TypeError, lambda: np.log(s))

    def test_cat_tab_completition(self):
        # test the tab completion display
        ok_for_cat = ['categories', 'codes', 'ordered', 'set_categories',
                      'add_categories', 'remove_categories',
                      'rename_categories', 'reorder_categories',
                      'remove_unused_categories', 'as_ordered', 'as_unordered']

        def get_dir(s):
            results = [r for r in s.cat.__dir__() if not r.startswith('_')]
            return list(sorted(set(results)))

        s = Series(list('aabbcde')).astype('category')
        results = get_dir(s)
        tm.assert_almost_equal(results, list(sorted(set(ok_for_cat))))

    def test_cat_accessor_api(self):
        # GH 9322
        from pandas.core.categorical import CategoricalAccessor
        self.assertIs(Series.cat, CategoricalAccessor)
        s = Series(list('aabbcde')).astype('category')
        self.assertIsInstance(s.cat, CategoricalAccessor)

        invalid = Series([1])
        with tm.assertRaisesRegexp(AttributeError, "only use .cat accessor"):
            invalid.cat
        self.assertFalse(hasattr(invalid, 'cat'))

    def test_cat_accessor_no_new_attributes(self):
        # https://github.com/pydata/pandas/issues/10673
        c = Series(list('aabbcde')).astype('category')
        with tm.assertRaisesRegexp(AttributeError,
                                   "You cannot add any new attribute"):
            c.cat.xlabel = "a"

    def test_str_accessor_api_for_categorical(self):
        # https://github.com/pydata/pandas/issues/10661
        from pandas.core.strings import StringMethods
        s = Series(list('aabb'))
        s = s + " " + s
        c = s.astype('category')
        self.assertIsInstance(c.str, StringMethods)

        # str functions, which need special arguments
        special_func_defs = [
            ('cat', (list("zyxw"),), {"sep": ","}),
            ('center', (10,), {}),
            ('contains', ("a",), {}),
            ('count', ("a",), {}),
            ('decode', ("UTF-8",), {}),
            ('encode', ("UTF-8",), {}),
            ('endswith', ("a",), {}),
            ('extract', ("([a-z]*) ",), {"expand":False}),
            ('extract', ("([a-z]*) ",), {"expand":True}),
            ('extractall', ("([a-z]*) ",), {}),
            ('find', ("a",), {}),
            ('findall', ("a",), {}),
            ('index', (" ",), {}),
            ('ljust', (10,), {}),
            ('match', ("a"), {}),  # deprecated...
            ('normalize', ("NFC",), {}),
            ('pad', (10,), {}),
            ('partition', (" ",), {"expand": False}),  # not default
            ('partition', (" ",), {"expand": True}),  # default
            ('repeat', (3,), {}),
            ('replace', ("a", "z"), {}),
            ('rfind', ("a",), {}),
            ('rindex', (" ",), {}),
            ('rjust', (10,), {}),
            ('rpartition', (" ",), {"expand": False}),  # not default
            ('rpartition', (" ",), {"expand": True}),  # default
            ('slice', (0, 1), {}),
            ('slice_replace', (0, 1, "z"), {}),
            ('split', (" ",), {"expand": False}),  # default
            ('split', (" ",), {"expand": True}),  # not default
            ('startswith', ("a",), {}),
            ('wrap', (2,), {}),
            ('zfill', (10,), {})
        ]
        _special_func_names = [f[0] for f in special_func_defs]

        # * get, join: they need a individual elements of type lists, but
        #   we can't make a categorical with lists as individual categories.
        #   -> `s.str.split(" ").astype("category")` will error!
        # * `translate` has different interfaces for py2 vs. py3
        _ignore_names = ["get", "join", "translate"]

        str_func_names = [f
                          for f in dir(s.str)
                          if not (f.startswith("_") or f in _special_func_names
                                  or f in _ignore_names)]

        func_defs = [(f, (), {}) for f in str_func_names]
        func_defs.extend(special_func_defs)

        for func, args, kwargs in func_defs:
            res = getattr(c.str, func)(*args, **kwargs)
            exp = getattr(s.str, func)(*args, **kwargs)

            if isinstance(res, pd.DataFrame):
                tm.assert_frame_equal(res, exp)
            else:
                tm.assert_series_equal(res, exp)

        invalid = Series([1, 2, 3]).astype('category')
        with tm.assertRaisesRegexp(AttributeError,
                                   "Can only use .str accessor with string"):
            invalid.str
        self.assertFalse(hasattr(invalid, 'str'))

    def test_dt_accessor_api_for_categorical(self):
        # https://github.com/pydata/pandas/issues/10661
        from pandas.tseries.common import Properties
        from pandas.tseries.index import date_range, DatetimeIndex
        from pandas.tseries.period import period_range, PeriodIndex
        from pandas.tseries.tdi import timedelta_range, TimedeltaIndex

        s_dr = Series(date_range('1/1/2015', periods=5, tz="MET"))
        c_dr = s_dr.astype("category")

        s_pr = Series(period_range('1/1/2015', freq='D', periods=5))
        c_pr = s_pr.astype("category")

        s_tdr = Series(timedelta_range('1 days', '10 days'))
        c_tdr = s_tdr.astype("category")

        test_data = [
            ("Datetime", DatetimeIndex._datetimelike_ops, s_dr, c_dr),
            ("Period", PeriodIndex._datetimelike_ops, s_pr, c_pr),
            ("Timedelta", TimedeltaIndex._datetimelike_ops, s_tdr, c_tdr)]

        self.assertIsInstance(c_dr.dt, Properties)

        special_func_defs = [
            ('strftime', ("%Y-%m-%d",), {}),
            ('tz_convert', ("EST",), {}),
            ('round', ("D",), {}),
            ('floor', ("D",), {}),
            ('ceil', ("D",), {}),
            # ('tz_localize', ("UTC",), {}),
        ]
        _special_func_names = [f[0] for f in special_func_defs]

        # the series is already localized
        _ignore_names = ['tz_localize']

        for name, attr_names, s, c in test_data:
            func_names = [f
                          for f in dir(s.dt)
                          if not (f.startswith("_") or f in attr_names or f in
                                  _special_func_names or f in _ignore_names)]

            func_defs = [(f, (), {}) for f in func_names]
            for f_def in special_func_defs:
                if f_def[0] in dir(s.dt):
                    func_defs.append(f_def)

            for func, args, kwargs in func_defs:
                res = getattr(c.dt, func)(*args, **kwargs)
                exp = getattr(s.dt, func)(*args, **kwargs)

                if isinstance(res, pd.DataFrame):
                    tm.assert_frame_equal(res, exp)
                elif isinstance(res, pd.Series):
                    tm.assert_series_equal(res, exp)
                else:
                    tm.assert_numpy_array_equal(res, exp)

            for attr in attr_names:
                try:
                    res = getattr(c.dt, attr)
                    exp = getattr(s.dt, attr)
                except Exception as e:
                    print(name, attr)
                    raise e

            if isinstance(res, pd.DataFrame):
                tm.assert_frame_equal(res, exp)
            elif isinstance(res, pd.Series):
                tm.assert_series_equal(res, exp)
            else:
                tm.assert_numpy_array_equal(res, exp)

        invalid = Series([1, 2, 3]).astype('category')
        with tm.assertRaisesRegexp(
                AttributeError, "Can only use .dt accessor with datetimelike"):
            invalid.dt
        self.assertFalse(hasattr(invalid, 'str'))

    def test_concat_categorical(self):
        # See GH 10177
        df1 = pd.DataFrame(
            np.arange(18, dtype='int64').reshape(6,
                                                 3), columns=["a", "b", "c"])

        df2 = pd.DataFrame(
            np.arange(14, dtype='int64').reshape(7, 2), columns=["a", "c"])
        df2['h'] = pd.Series(pd.Categorical(["one", "one", "two", "one", "two",
                                             "two", "one"]))

        df_concat = pd.concat((df1, df2), axis=0).reset_index(drop=True)

        df_expected = pd.DataFrame(
            {'a': [0, 3, 6, 9, 12, 15, 0, 2, 4, 6, 8, 10, 12],
             'b': [1, 4, 7, 10, 13, 16, np.nan, np.nan, np.nan, np.nan, np.nan,
                   np.nan, np.nan],
             'c': [2, 5, 8, 11, 14, 17, 1, 3, 5, 7, 9, 11, 13]})
        df_expected['h'] = pd.Series(pd.Categorical(
            [None, None, None, None, None, None, "one", "one", "two", "one",
             "two", "two", "one"]))

        tm.assert_frame_equal(df_expected, df_concat)


if __name__ == '__main__':
    import nose
    nose.runmodule(argv=[__file__, '-vvs', '-x', '--pdb', '--pdb-failure'],
                   # '--with-coverage', '--cover-package=pandas.core']
                   exit=False)