test_range.py

# -*- coding: utf-8 -*-

from datetime import datetime
from itertools import combinations
import operator

from pandas.compat import range, u, PY3

import numpy as np

from pandas import (Series, Index, Float64Index, Int64Index, RangeIndex)
from pandas.util.testing import assertRaisesRegexp

import pandas.util.testing as tm

import pandas as pd

from .test_numeric import Numeric


class TestRangeIndex(Numeric, tm.TestCase):
    _holder = RangeIndex
    _compat_props = ['shape', 'ndim', 'size', 'itemsize']

    def setUp(self):
        self.indices = dict(index=RangeIndex(0, 20, 2, name='foo'))
        self.setup_indices()

    def create_index(self):
        return RangeIndex(5)

    def check_binop(self, ops, scalars, idxs):
        for op in ops:
            for a, b in combinations(idxs, 2):
                result = op(a, b)
                expected = op(Int64Index(a), Int64Index(b))
                tm.assert_index_equal(result, expected)
            for idx in idxs:
                for scalar in scalars:
                    result = op(idx, scalar)
                    expected = op(Int64Index(idx), scalar)
                    tm.assert_index_equal(result, expected)

    def test_binops(self):
        ops = [operator.add, operator.sub, operator.mul, operator.floordiv,
               operator.truediv]
        scalars = [-1, 1, 2]
        idxs = [RangeIndex(0, 10, 1), RangeIndex(0, 20, 2),
                RangeIndex(-10, 10, 2), RangeIndex(5, -5, -1)]
        self.check_binop(ops, scalars, idxs)

    def test_binops_pow(self):
        # later versions of numpy don't allow powers of negative integers
        # so test separately
        # https://github.com/numpy/numpy/pull/8127
        ops = [pow]
        scalars = [1, 2]
        idxs = [RangeIndex(0, 10, 1), RangeIndex(0, 20, 2)]
        self.check_binop(ops, scalars, idxs)

    def test_too_many_names(self):
        def testit():
            self.index.names = ["roger", "harold"]

        assertRaisesRegexp(ValueError, "^Length", testit)

    def test_constructor(self):
        index = RangeIndex(5)
        expected = np.arange(5, dtype=np.int64)
        self.assertIsInstance(index, RangeIndex)
        self.assertEqual(index._start, 0)
        self.assertEqual(index._stop, 5)
        self.assertEqual(index._step, 1)
        self.assertEqual(index.name, None)
        tm.assert_index_equal(Index(expected), index)

        index = RangeIndex(1, 5)
        expected = np.arange(1, 5, dtype=np.int64)
        self.assertIsInstance(index, RangeIndex)
        self.assertEqual(index._start, 1)
        tm.assert_index_equal(Index(expected), index)

        index = RangeIndex(1, 5, 2)
        expected = np.arange(1, 5, 2, dtype=np.int64)
        self.assertIsInstance(index, RangeIndex)
        self.assertEqual(index._step, 2)
        tm.assert_index_equal(Index(expected), index)

        msg = "RangeIndex\\(\\.\\.\\.\\) must be called with integers"
        with tm.assertRaisesRegexp(TypeError, msg):
            RangeIndex()

        for index in [RangeIndex(0), RangeIndex(start=0), RangeIndex(stop=0),
                      RangeIndex(0, 0)]:
            expected = np.empty(0, dtype=np.int64)
            self.assertIsInstance(index, RangeIndex)
            self.assertEqual(index._start, 0)
            self.assertEqual(index._stop, 0)
            self.assertEqual(index._step, 1)
            tm.assert_index_equal(Index(expected), index)

        with tm.assertRaisesRegexp(TypeError, msg):
            RangeIndex(name='Foo')

        for index in [RangeIndex(0, name='Foo'),
                      RangeIndex(start=0, name='Foo'),
                      RangeIndex(stop=0, name='Foo'),
                      RangeIndex(0, 0, name='Foo')]:
            self.assertIsInstance(index, RangeIndex)
            self.assertEqual(index.name, 'Foo')

        # we don't allow on a bare Index
        self.assertRaises(TypeError, lambda: Index(0, 1000))

        # invalid args
        for i in [Index(['a', 'b']), Series(['a', 'b']), np.array(['a', 'b']),
                  [], 'foo', datetime(2000, 1, 1, 0, 0), np.arange(0, 10),
                  np.array([1]), [1]]:
            self.assertRaises(TypeError, lambda: RangeIndex(i))

    def test_constructor_same(self):

        # pass thru w and w/o copy
        index = RangeIndex(1, 5, 2)
        result = RangeIndex(index, copy=False)
        self.assertTrue(result.identical(index))

        result = RangeIndex(index, copy=True)
        self.assert_index_equal(result, index, exact=True)

        result = RangeIndex(index)
        self.assert_index_equal(result, index, exact=True)

        self.assertRaises(TypeError,
                          lambda: RangeIndex(index, dtype='float64'))

    def test_constructor_range(self):

        self.assertRaises(TypeError, lambda: RangeIndex(range(1, 5, 2)))

        result = RangeIndex.from_range(range(1, 5, 2))
        expected = RangeIndex(1, 5, 2)
        self.assert_index_equal(result, expected, exact=True)

        result = RangeIndex.from_range(range(5, 6))
        expected = RangeIndex(5, 6, 1)
        self.assert_index_equal(result, expected, exact=True)

        # an invalid range
        result = RangeIndex.from_range(range(5, 1))
        expected = RangeIndex(0, 0, 1)
        self.assert_index_equal(result, expected, exact=True)

        result = RangeIndex.from_range(range(5))
        expected = RangeIndex(0, 5, 1)
        self.assert_index_equal(result, expected, exact=True)

        result = Index(range(1, 5, 2))
        expected = RangeIndex(1, 5, 2)
        self.assert_index_equal(result, expected, exact=True)

        self.assertRaises(TypeError,
                          lambda: Index(range(1, 5, 2), dtype='float64'))

    def test_constructor_name(self):
        # GH12288
        orig = RangeIndex(10)
        orig.name = 'original'

        copy = RangeIndex(orig)
        copy.name = 'copy'

        self.assertTrue(orig.name, 'original')
        self.assertTrue(copy.name, 'copy')

        new = Index(copy)
        self.assertTrue(new.name, 'copy')

        new.name = 'new'
        self.assertTrue(orig.name, 'original')
        self.assertTrue(new.name, 'copy')
        self.assertTrue(new.name, 'new')

    def test_numeric_compat2(self):
        # validate that we are handling the RangeIndex overrides to numeric ops
        # and returning RangeIndex where possible

        idx = RangeIndex(0, 10, 2)

        result = idx * 2
        expected = RangeIndex(0, 20, 4)
        self.assert_index_equal(result, expected, exact=True)

        result = idx + 2
        expected = RangeIndex(2, 12, 2)
        self.assert_index_equal(result, expected, exact=True)

        result = idx - 2
        expected = RangeIndex(-2, 8, 2)
        self.assert_index_equal(result, expected, exact=True)

        # truediv under PY3
        result = idx / 2

        if PY3:
            expected = RangeIndex(0, 5, 1).astype('float64')
        else:
            expected = RangeIndex(0, 5, 1)
        self.assert_index_equal(result, expected, exact=True)

        result = idx / 4
        expected = RangeIndex(0, 10, 2) / 4
        self.assert_index_equal(result, expected, exact=True)

        result = idx // 1
        expected = idx
        tm.assert_index_equal(result, expected, exact=True)

        # __mul__
        result = idx * idx
        expected = Index(idx.values * idx.values)
        tm.assert_index_equal(result, expected, exact=True)

        # __pow__
        idx = RangeIndex(0, 1000, 2)
        result = idx ** 2
        expected = idx._int64index ** 2
        tm.assert_index_equal(Index(result.values), expected, exact=True)

        # __floordiv__
        cases_exact = [(RangeIndex(0, 1000, 2), 2, RangeIndex(0, 500, 1)),
                       (RangeIndex(-99, -201, -3), -3, RangeIndex(33, 67, 1)),
                       (RangeIndex(0, 1000, 1), 2,
                        RangeIndex(0, 1000, 1)._int64index // 2),
                       (RangeIndex(0, 100, 1), 2.0,
                        RangeIndex(0, 100, 1)._int64index // 2.0),
                       (RangeIndex(0), 50, RangeIndex(0)),
                       (RangeIndex(2, 4, 2), 3, RangeIndex(0, 1, 1)),
                       (RangeIndex(-5, -10, -6), 4, RangeIndex(-2, -1, 1)),
                       (RangeIndex(-100, -200, 3), 2, RangeIndex(0))]
        for idx, div, expected in cases_exact:
            tm.assert_index_equal(idx // div, expected, exact=True)

    def test_constructor_corner(self):
        arr = np.array([1, 2, 3, 4], dtype=object)
        index = RangeIndex(1, 5)
        self.assertEqual(index.values.dtype, np.int64)
        self.assert_index_equal(index, Index(arr))

        # non-int raise Exception
        self.assertRaises(TypeError, RangeIndex, '1', '10', '1')
        self.assertRaises(TypeError, RangeIndex, 1.1, 10.2, 1.3)

        # invalid passed type
        self.assertRaises(TypeError, lambda: RangeIndex(1, 5, dtype='float64'))

    def test_copy(self):
        i = RangeIndex(5, name='Foo')
        i_copy = i.copy()
        self.assertTrue(i_copy is not i)
        self.assertTrue(i_copy.identical(i))
        self.assertEqual(i_copy._start, 0)
        self.assertEqual(i_copy._stop, 5)
        self.assertEqual(i_copy._step, 1)
        self.assertEqual(i_copy.name, 'Foo')

    def test_repr(self):
        i = RangeIndex(5, name='Foo')
        result = repr(i)
        if PY3:
            expected = "RangeIndex(start=0, stop=5, step=1, name='Foo')"
        else:
            expected = "RangeIndex(start=0, stop=5, step=1, name=u'Foo')"
        self.assertTrue(result, expected)

        result = eval(result)
        self.assert_index_equal(result, i, exact=True)

        i = RangeIndex(5, 0, -1)
        result = repr(i)
        expected = "RangeIndex(start=5, stop=0, step=-1)"
        self.assertEqual(result, expected)

        result = eval(result)
        self.assert_index_equal(result, i, exact=True)

    def test_insert(self):

        idx = RangeIndex(5, name='Foo')
        result = idx[1:4]

        # test 0th element
        self.assert_index_equal(idx[0:4], result.insert(0, idx[0]))

    def test_delete(self):

        idx = RangeIndex(5, name='Foo')
        expected = idx[1:].astype(int)
        result = idx.delete(0)
        self.assert_index_equal(result, expected)
        self.assertEqual(result.name, expected.name)

        expected = idx[:-1].astype(int)
        result = idx.delete(-1)
        self.assert_index_equal(result, expected)
        self.assertEqual(result.name, expected.name)

        with tm.assertRaises((IndexError, ValueError)):
            # either depending on numpy version
            result = idx.delete(len(idx))

    def test_view(self):
        super(TestRangeIndex, self).test_view()

        i = RangeIndex(0, name='Foo')
        i_view = i.view()
        self.assertEqual(i_view.name, 'Foo')

        i_view = i.view('i8')
        tm.assert_numpy_array_equal(i.values, i_view)

        i_view = i.view(RangeIndex)
        tm.assert_index_equal(i, i_view)

    def test_dtype(self):
        self.assertEqual(self.index.dtype, np.int64)

    def test_is_monotonic(self):
        self.assertTrue(self.index.is_monotonic)
        self.assertTrue(self.index.is_monotonic_increasing)
        self.assertFalse(self.index.is_monotonic_decreasing)

        index = RangeIndex(4, 0, -1)
        self.assertFalse(index.is_monotonic)
        self.assertTrue(index.is_monotonic_decreasing)

        index = RangeIndex(1, 2)
        self.assertTrue(index.is_monotonic)
        self.assertTrue(index.is_monotonic_increasing)
        self.assertTrue(index.is_monotonic_decreasing)

        index = RangeIndex(2, 1)
        self.assertTrue(index.is_monotonic)
        self.assertTrue(index.is_monotonic_increasing)
        self.assertTrue(index.is_monotonic_decreasing)

        index = RangeIndex(1, 1)
        self.assertTrue(index.is_monotonic)
        self.assertTrue(index.is_monotonic_increasing)
        self.assertTrue(index.is_monotonic_decreasing)

    def test_equals_range(self):
        equiv_pairs = [(RangeIndex(0, 9, 2), RangeIndex(0, 10, 2)),
                       (RangeIndex(0), RangeIndex(1, -1, 3)),
                       (RangeIndex(1, 2, 3), RangeIndex(1, 3, 4)),
                       (RangeIndex(0, -9, -2), RangeIndex(0, -10, -2))]
        for left, right in equiv_pairs:
            self.assertTrue(left.equals(right))
            self.assertTrue(right.equals(left))

    def test_logical_compat(self):
        idx = self.create_index()
        self.assertEqual(idx.all(), idx.values.all())
        self.assertEqual(idx.any(), idx.values.any())

    def test_identical(self):
        i = Index(self.index.copy())
        self.assertTrue(i.identical(self.index))

        # we don't allow object dtype for RangeIndex
        if isinstance(self.index, RangeIndex):
            return

        same_values_different_type = Index(i, dtype=object)
        self.assertFalse(i.identical(same_values_different_type))

        i = self.index.copy(dtype=object)
        i = i.rename('foo')
        same_values = Index(i, dtype=object)
        self.assertTrue(same_values.identical(self.index.copy(dtype=object)))

        self.assertFalse(i.identical(self.index))
        self.assertTrue(Index(same_values, name='foo', dtype=object).identical(
            i))

        self.assertFalse(self.index.copy(dtype=object)
                         .identical(self.index.copy(dtype='int64')))

    def test_get_indexer(self):
        target = RangeIndex(10)
        indexer = self.index.get_indexer(target)
        expected = np.array([0, -1, 1, -1, 2, -1, 3, -1, 4, -1], dtype=np.intp)
        self.assert_numpy_array_equal(indexer, expected)

    def test_get_indexer_pad(self):
        target = RangeIndex(10)
        indexer = self.index.get_indexer(target, method='pad')
        expected = np.array([0, 0, 1, 1, 2, 2, 3, 3, 4, 4], dtype=np.intp)
        self.assert_numpy_array_equal(indexer, expected)

    def test_get_indexer_backfill(self):
        target = RangeIndex(10)
        indexer = self.index.get_indexer(target, method='backfill')
        expected = np.array([0, 1, 1, 2, 2, 3, 3, 4, 4, 5], dtype=np.intp)
        self.assert_numpy_array_equal(indexer, expected)

    def test_join_outer(self):
        # join with Int64Index
        other = Int64Index(np.arange(25, 14, -1))

        res, lidx, ridx = self.index.join(other, how='outer',
                                          return_indexers=True)
        noidx_res = self.index.join(other, how='outer')
        self.assert_index_equal(res, noidx_res)

        eres = Int64Index([0, 2, 4, 6, 8, 10, 12, 14, 15, 16, 17, 18, 19, 20,
                           21, 22, 23, 24, 25])
        elidx = np.array([0, 1, 2, 3, 4, 5, 6, 7, -1, 8, -1, 9,
                          -1, -1, -1, -1, -1, -1, -1], dtype=np.intp)
        eridx = np.array([-1, -1, -1, -1, -1, -1, -1, -1, 10, 9, 8, 7, 6,
                          5, 4, 3, 2, 1, 0], dtype=np.intp)

        self.assertIsInstance(res, Int64Index)
        self.assertFalse(isinstance(res, RangeIndex))
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assert_numpy_array_equal(ridx, eridx)

        # join with RangeIndex
        other = RangeIndex(25, 14, -1)

        res, lidx, ridx = self.index.join(other, how='outer',
                                          return_indexers=True)
        noidx_res = self.index.join(other, how='outer')
        self.assert_index_equal(res, noidx_res)

        self.assertIsInstance(res, Int64Index)
        self.assertFalse(isinstance(res, RangeIndex))
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assert_numpy_array_equal(ridx, eridx)

    def test_join_inner(self):
        # Join with non-RangeIndex
        other = Int64Index(np.arange(25, 14, -1))

        res, lidx, ridx = self.index.join(other, how='inner',
                                          return_indexers=True)

        # no guarantee of sortedness, so sort for comparison purposes
        ind = res.argsort()
        res = res.take(ind)
        lidx = lidx.take(ind)
        ridx = ridx.take(ind)

        eres = Int64Index([16, 18])
        elidx = np.array([8, 9], dtype=np.intp)
        eridx = np.array([9, 7], dtype=np.intp)

        self.assertIsInstance(res, Int64Index)
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assert_numpy_array_equal(ridx, eridx)

        # Join two RangeIndex
        other = RangeIndex(25, 14, -1)

        res, lidx, ridx = self.index.join(other, how='inner',
                                          return_indexers=True)

        self.assertIsInstance(res, RangeIndex)
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assert_numpy_array_equal(ridx, eridx)

    def test_join_left(self):
        # Join with Int64Index
        other = Int64Index(np.arange(25, 14, -1))

        res, lidx, ridx = self.index.join(other, how='left',
                                          return_indexers=True)
        eres = self.index
        eridx = np.array([-1, -1, -1, -1, -1, -1, -1, -1, 9, 7], dtype=np.intp)

        self.assertIsInstance(res, RangeIndex)
        self.assert_index_equal(res, eres)
        self.assertIsNone(lidx)
        self.assert_numpy_array_equal(ridx, eridx)

        # Join withRangeIndex
        other = Int64Index(np.arange(25, 14, -1))

        res, lidx, ridx = self.index.join(other, how='left',
                                          return_indexers=True)

        self.assertIsInstance(res, RangeIndex)
        self.assert_index_equal(res, eres)
        self.assertIsNone(lidx)
        self.assert_numpy_array_equal(ridx, eridx)

    def test_join_right(self):
        # Join with Int64Index
        other = Int64Index(np.arange(25, 14, -1))

        res, lidx, ridx = self.index.join(other, how='right',
                                          return_indexers=True)
        eres = other
        elidx = np.array([-1, -1, -1, -1, -1, -1, -1, 9, -1, 8, -1],
                         dtype=np.intp)

        self.assertIsInstance(other, Int64Index)
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assertIsNone(ridx)

        # Join withRangeIndex
        other = RangeIndex(25, 14, -1)

        res, lidx, ridx = self.index.join(other, how='right',
                                          return_indexers=True)
        eres = other

        self.assertIsInstance(other, RangeIndex)
        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assertIsNone(ridx)

    def test_join_non_int_index(self):
        other = Index([3, 6, 7, 8, 10], dtype=object)

        outer = self.index.join(other, how='outer')
        outer2 = other.join(self.index, how='outer')
        expected = Index([0, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16, 18])
        self.assert_index_equal(outer, outer2)
        self.assert_index_equal(outer, expected)

        inner = self.index.join(other, how='inner')
        inner2 = other.join(self.index, how='inner')
        expected = Index([6, 8, 10])
        self.assert_index_equal(inner, inner2)
        self.assert_index_equal(inner, expected)

        left = self.index.join(other, how='left')
        self.assert_index_equal(left, self.index.astype(object))

        left2 = other.join(self.index, how='left')
        self.assert_index_equal(left2, other)

        right = self.index.join(other, how='right')
        self.assert_index_equal(right, other)

        right2 = other.join(self.index, how='right')
        self.assert_index_equal(right2, self.index.astype(object))

    def test_join_non_unique(self):
        other = Index([4, 4, 3, 3])

        res, lidx, ridx = self.index.join(other, return_indexers=True)

        eres = Int64Index([0, 2, 4, 4, 6, 8, 10, 12, 14, 16, 18])
        elidx = np.array([0, 1, 2, 2, 3, 4, 5, 6, 7, 8, 9], dtype=np.intp)
        eridx = np.array([-1, -1, 0, 1, -1, -1, -1, -1, -1, -1, -1],
                         dtype=np.intp)

        self.assert_index_equal(res, eres)
        self.assert_numpy_array_equal(lidx, elidx)
        self.assert_numpy_array_equal(ridx, eridx)

    def test_join_self(self):
        kinds = 'outer', 'inner', 'left', 'right'
        for kind in kinds:
            joined = self.index.join(self.index, how=kind)
            self.assertIs(self.index, joined)

    def test_intersection(self):
        # intersect with Int64Index
        other = Index(np.arange(1, 6))
        result = self.index.intersection(other)
        expected = Index(np.sort(np.intersect1d(self.index.values,
                                                other.values)))
        self.assert_index_equal(result, expected)

        result = other.intersection(self.index)
        expected = Index(np.sort(np.asarray(np.intersect1d(self.index.values,
                                                           other.values))))
        self.assert_index_equal(result, expected)

        # intersect with increasing RangeIndex
        other = RangeIndex(1, 6)
        result = self.index.intersection(other)
        expected = Index(np.sort(np.intersect1d(self.index.values,
                                                other.values)))
        self.assert_index_equal(result, expected)

        # intersect with decreasing RangeIndex
        other = RangeIndex(5, 0, -1)
        result = self.index.intersection(other)
        expected = Index(np.sort(np.intersect1d(self.index.values,
                                                other.values)))
        self.assert_index_equal(result, expected)

        index = RangeIndex(5)

        # intersect of non-overlapping indices
        other = RangeIndex(5, 10, 1)
        result = index.intersection(other)
        expected = RangeIndex(0, 0, 1)
        self.assert_index_equal(result, expected)

        other = RangeIndex(-1, -5, -1)
        result = index.intersection(other)
        expected = RangeIndex(0, 0, 1)
        self.assert_index_equal(result, expected)

        # intersection of empty indices
        other = RangeIndex(0, 0, 1)
        result = index.intersection(other)
        expected = RangeIndex(0, 0, 1)
        self.assert_index_equal(result, expected)

        result = other.intersection(index)
        self.assert_index_equal(result, expected)

        # intersection of non-overlapping values based on start value and gcd
        index = RangeIndex(1, 10, 2)
        other = RangeIndex(0, 10, 4)
        result = index.intersection(other)
        expected = RangeIndex(0, 0, 1)
        self.assert_index_equal(result, expected)

    def test_intersect_str_dates(self):
        dt_dates = [datetime(2012, 2, 9), datetime(2012, 2, 22)]

        i1 = Index(dt_dates, dtype=object)
        i2 = Index(['aa'], dtype=object)
        res = i2.intersection(i1)

        self.assertEqual(len(res), 0)

    def test_union_noncomparable(self):
        from datetime import datetime, timedelta
        # corner case, non-Int64Index
        now = datetime.now()
        other = Index([now + timedelta(i) for i in range(4)], dtype=object)
        result = self.index.union(other)
        expected = Index(np.concatenate((self.index, other)))
        self.assert_index_equal(result, expected)

        result = other.union(self.index)
        expected = Index(np.concatenate((other, self.index)))
        self.assert_index_equal(result, expected)

    def test_union(self):
        RI = RangeIndex
        I64 = Int64Index
        cases = [(RI(0, 10, 1), RI(0, 10, 1), RI(0, 10, 1)),
                 (RI(0, 10, 1), RI(5, 20, 1), RI(0, 20, 1)),
                 (RI(0, 10, 1), RI(10, 20, 1), RI(0, 20, 1)),
                 (RI(0, -10, -1), RI(0, -10, -1), RI(0, -10, -1)),
                 (RI(0, -10, -1), RI(-10, -20, -1), RI(-19, 1, 1)),
                 (RI(0, 10, 2), RI(1, 10, 2), RI(0, 10, 1)),
                 (RI(0, 11, 2), RI(1, 12, 2), RI(0, 12, 1)),
                 (RI(0, 21, 4), RI(-2, 24, 4), RI(-2, 24, 2)),
                 (RI(0, -20, -2), RI(-1, -21, -2), RI(-19, 1, 1)),
                 (RI(0, 100, 5), RI(0, 100, 20), RI(0, 100, 5)),
                 (RI(0, -100, -5), RI(5, -100, -20), RI(-95, 10, 5)),
                 (RI(0, -11, -1), RI(1, -12, -4), RI(-11, 2, 1)),
                 (RI(0), RI(0), RI(0)),
                 (RI(0, -10, -2), RI(0), RI(0, -10, -2)),
                 (RI(0, 100, 2), RI(100, 150, 200), RI(0, 102, 2)),
                 (RI(0, -100, -2), RI(-100, 50, 102), RI(-100, 4, 2)),
                 (RI(0, -100, -1), RI(0, -50, -3), RI(-99, 1, 1)),
                 (RI(0, 1, 1), RI(5, 6, 10), RI(0, 6, 5)),
                 (RI(0, 10, 5), RI(-5, -6, -20), RI(-5, 10, 5)),
                 (RI(0, 3, 1), RI(4, 5, 1), I64([0, 1, 2, 4])),
                 (RI(0, 10, 1), I64([]), RI(0, 10, 1)),
                 (RI(0), I64([1, 5, 6]), I64([1, 5, 6]))]
        for idx1, idx2, expected in cases:
            res1 = idx1.union(idx2)
            res2 = idx2.union(idx1)
            res3 = idx1._int64index.union(idx2)
            tm.assert_index_equal(res1, expected, exact=True)
            tm.assert_index_equal(res2, expected, exact=True)
            tm.assert_index_equal(res3, expected)

    def test_nbytes(self):

        # memory savings vs int index
        i = RangeIndex(0, 1000)
        self.assertTrue(i.nbytes < i.astype(int).nbytes / 10)

        # constant memory usage
        i2 = RangeIndex(0, 10)
        self.assertEqual(i.nbytes, i2.nbytes)

    def test_cant_or_shouldnt_cast(self):
        # can't
        self.assertRaises(TypeError, RangeIndex, 'foo', 'bar', 'baz')

        # shouldn't
        self.assertRaises(TypeError, RangeIndex, '0', '1', '2')

    def test_view_Index(self):
        self.index.view(Index)

    def test_prevent_casting(self):
        result = self.index.astype('O')
        self.assertEqual(result.dtype, np.object_)

    def test_take_preserve_name(self):
        index = RangeIndex(1, 5, name='foo')
        taken = index.take([3, 0, 1])
        self.assertEqual(index.name, taken.name)

    def test_take_fill_value(self):
        # GH 12631
        idx = pd.RangeIndex(1, 4, name='xxx')
        result = idx.take(np.array([1, 0, -1]))
        expected = pd.Int64Index([2, 1, 3], name='xxx')
        tm.assert_index_equal(result, expected)

        # fill_value
        msg = "Unable to fill values because RangeIndex cannot contain NA"
        with tm.assertRaisesRegexp(ValueError, msg):
            idx.take(np.array([1, 0, -1]), fill_value=True)

        # allow_fill=False
        result = idx.take(np.array([1, 0, -1]), allow_fill=False,
                          fill_value=True)
        expected = pd.Int64Index([2, 1, 3], name='xxx')
        tm.assert_index_equal(result, expected)

        msg = "Unable to fill values because RangeIndex cannot contain NA"
        with tm.assertRaisesRegexp(ValueError, msg):
            idx.take(np.array([1, 0, -2]), fill_value=True)
        with tm.assertRaisesRegexp(ValueError, msg):
            idx.take(np.array([1, 0, -5]), fill_value=True)

        with tm.assertRaises(IndexError):
            idx.take(np.array([1, -5]))

    def test_print_unicode_columns(self):
        df = pd.DataFrame({u("\u05d0"): [1, 2, 3],
                           "\u05d1": [4, 5, 6],
                           "c": [7, 8, 9]})
        repr(df.columns)  # should not raise UnicodeDecodeError

    def test_repr_roundtrip(self):
        tm.assert_index_equal(eval(repr(self.index)), self.index)

    def test_slice_keep_name(self):
        idx = RangeIndex(1, 2, name='asdf')
        self.assertEqual(idx.name, idx[1:].name)

    def test_explicit_conversions(self):

        # GH 8608
        # add/sub are overriden explicity for Float/Int Index
        idx = RangeIndex(5)

        # float conversions
        arr = np.arange(5, dtype='int64') * 3.2
        expected = Float64Index(arr)
        fidx = idx * 3.2
        tm.assert_index_equal(fidx, expected)
        fidx = 3.2 * idx
        tm.assert_index_equal(fidx, expected)

        # interops with numpy arrays
        expected = Float64Index(arr)
        a = np.zeros(5, dtype='float64')
        result = fidx - a
        tm.assert_index_equal(result, expected)

        expected = Float64Index(-arr)
        a = np.zeros(5, dtype='float64')
        result = a - fidx
        tm.assert_index_equal(result, expected)

    def test_duplicates(self):
        for ind in self.indices:
            if not len(ind):
                continue
            idx = self.indices[ind]
            self.assertTrue(idx.is_unique)
            self.assertFalse(idx.has_duplicates)

    def test_ufunc_compat(self):
        idx = RangeIndex(5)
        result = np.sin(idx)
        expected = Float64Index(np.sin(np.arange(5, dtype='int64')))
        tm.assert_index_equal(result, expected)

    def test_extended_gcd(self):
        result = self.index._extended_gcd(6, 10)
        self.assertEqual(result[0], result[1] * 6 + result[2] * 10)
        self.assertEqual(2, result[0])

        result = self.index._extended_gcd(10, 6)
        self.assertEqual(2, result[1] * 10 + result[2] * 6)
        self.assertEqual(2, result[0])

    def test_min_fitting_element(self):
        result = RangeIndex(0, 20, 2)._min_fitting_element(1)
        self.assertEqual(2, result)

        result = RangeIndex(1, 6)._min_fitting_element(1)
        self.assertEqual(1, result)

        result = RangeIndex(18, -2, -2)._min_fitting_element(1)
        self.assertEqual(2, result)

        result = RangeIndex(5, 0, -1)._min_fitting_element(1)
        self.assertEqual(1, result)

        big_num = 500000000000000000000000

        result = RangeIndex(5, big_num * 2, 1)._min_fitting_element(big_num)
        self.assertEqual(big_num, result)

    def test_max_fitting_element(self):
        result = RangeIndex(0, 20, 2)._max_fitting_element(17)
        self.assertEqual(16, result)

        result = RangeIndex(1, 6)._max_fitting_element(4)
        self.assertEqual(4, result)

        result = RangeIndex(18, -2, -2)._max_fitting_element(17)
        self.assertEqual(16, result)

        result = RangeIndex(5, 0, -1)._max_fitting_element(4)
        self.assertEqual(4, result)

        big_num = 500000000000000000000000

        result = RangeIndex(5, big_num * 2, 1)._max_fitting_element(big_num)
        self.assertEqual(big_num, result)

    def test_pickle_compat_construction(self):
        # RangeIndex() is a valid constructor
        pass

    def test_slice_specialised(self):

        # scalar indexing
        res = self.index[1]
        expected = 2
        self.assertEqual(res, expected)

        res = self.index[-1]
        expected = 18
        self.assertEqual(res, expected)

        # slicing
        # slice value completion
        index = self.index[:]
        expected = self.index
        self.assert_index_equal(index, expected)

        # positive slice values
        index = self.index[7:10:2]
        expected = Index(np.array([14, 18]), name='foo')
        self.assert_index_equal(index, expected)

        # negative slice values
        index = self.index[-1:-5:-2]
        expected = Index(np.array([18, 14]), name='foo')
        self.assert_index_equal(index, expected)

        # stop overshoot
        index = self.index[2:100:4]
        expected = Index(np.array([4, 12]), name='foo')
        self.assert_index_equal(index, expected)

        # reverse
        index = self.index[::-1]
        expected = Index(self.index.values[::-1], name='foo')
        self.assert_index_equal(index, expected)

        index = self.index[-8::-1]
        expected = Index(np.array([4, 2, 0]), name='foo')
        self.assert_index_equal(index, expected)

        index = self.index[-40::-1]
        expected = Index(np.array([], dtype=np.int64), name='foo')
        self.assert_index_equal(index, expected)

        index = self.index[40::-1]
        expected = Index(self.index.values[40::-1], name='foo')
        self.assert_index_equal(index, expected)

        index = self.index[10::-1]
        expected = Index(self.index.values[::-1], name='foo')
        self.assert_index_equal(index, expected)

    def test_len_specialised(self):

        # make sure that our len is the same as
        # np.arange calc

        for step in np.arange(1, 6, 1):

            arr = np.arange(0, 5, step)
            i = RangeIndex(0, 5, step)
            self.assertEqual(len(i), len(arr))

            i = RangeIndex(5, 0, step)
            self.assertEqual(len(i), 0)

        for step in np.arange(-6, -1, 1):

            arr = np.arange(5, 0, step)
            i = RangeIndex(5, 0, step)
            self.assertEqual(len(i), len(arr))

            i = RangeIndex(0, 5, step)
            self.assertEqual(len(i), 0)