test_constructors.py

# coding=utf-8
# pylint: disable-msg=E1101,W0612

from datetime import datetime, timedelta

from numpy import nan
import numpy as np
import numpy.ma as ma
import pandas as pd

from pandas.types.common import is_categorical_dtype, is_datetime64tz_dtype
from pandas import Index, Series, isnull, date_range, period_range
from pandas.core.index import MultiIndex
from pandas.tseries.index import Timestamp, DatetimeIndex

import pandas.lib as lib

from pandas.compat import lrange, range, zip, OrderedDict, long
from pandas import compat
from pandas.util.testing import assert_series_equal
import pandas.util.testing as tm

from .common import TestData


class TestSeriesConstructors(TestData, tm.TestCase):

    _multiprocess_can_split_ = True

    def test_scalar_conversion(self):

        # Pass in scalar is disabled
        scalar = Series(0.5)
        self.assertNotIsInstance(scalar, float)

        # coercion
        self.assertEqual(float(Series([1.])), 1.0)
        self.assertEqual(int(Series([1.])), 1)
        self.assertEqual(long(Series([1.])), 1)

    def test_TimeSeries_deprecation(self):

        # deprecation TimeSeries, #10890
        with tm.assert_produces_warning(FutureWarning):
            pd.TimeSeries(1, index=date_range('20130101', periods=3))

    def test_constructor(self):
        # Recognize TimeSeries
        with tm.assert_produces_warning(FutureWarning):
            self.assertTrue(self.ts.is_time_series)
        self.assertTrue(self.ts.index.is_all_dates)

        # Pass in Series
        derived = Series(self.ts)
        with tm.assert_produces_warning(FutureWarning):
            self.assertTrue(derived.is_time_series)
        self.assertTrue(derived.index.is_all_dates)

        self.assertTrue(tm.equalContents(derived.index, self.ts.index))
        # Ensure new index is not created
        self.assertEqual(id(self.ts.index), id(derived.index))

        # Mixed type Series
        mixed = Series(['hello', np.NaN], index=[0, 1])
        self.assertEqual(mixed.dtype, np.object_)
        self.assertIs(mixed[1], np.NaN)

        with tm.assert_produces_warning(FutureWarning):
            self.assertFalse(self.empty.is_time_series)
        self.assertFalse(self.empty.index.is_all_dates)
        with tm.assert_produces_warning(FutureWarning):
            self.assertFalse(Series({}).is_time_series)
        self.assertFalse(Series({}).index.is_all_dates)
        self.assertRaises(Exception, Series, np.random.randn(3, 3),
                          index=np.arange(3))

        mixed.name = 'Series'
        rs = Series(mixed).name
        xp = 'Series'
        self.assertEqual(rs, xp)

        # raise on MultiIndex GH4187
        m = MultiIndex.from_arrays([[1, 2], [3, 4]])
        self.assertRaises(NotImplementedError, Series, m)

    def test_constructor_empty(self):
        empty = Series()
        empty2 = Series([])

        # the are Index() and RangeIndex() which don't compare type equal
        # but are just .equals
        assert_series_equal(empty, empty2, check_index_type=False)

        empty = Series(index=lrange(10))
        empty2 = Series(np.nan, index=lrange(10))
        assert_series_equal(empty, empty2)

    def test_constructor_series(self):
        index1 = ['d', 'b', 'a', 'c']
        index2 = sorted(index1)
        s1 = Series([4, 7, -5, 3], index=index1)
        s2 = Series(s1, index=index2)

        assert_series_equal(s2, s1.sort_index())

    def test_constructor_iterator(self):

        expected = Series(list(range(10)), dtype='int64')
        result = Series(range(10), dtype='int64')
        assert_series_equal(result, expected)

    def test_constructor_list_like(self):

        # make sure that we are coercing different
        # list-likes to standard dtypes and not
        # platform specific
        expected = Series([1, 2, 3], dtype='int64')
        for obj in [[1, 2, 3], (1, 2, 3),
                    np.array([1, 2, 3], dtype='int64')]:
            result = Series(obj, index=[0, 1, 2])
            assert_series_equal(result, expected)

    def test_constructor_generator(self):
        gen = (i for i in range(10))

        result = Series(gen)
        exp = Series(lrange(10))
        assert_series_equal(result, exp)

        gen = (i for i in range(10))
        result = Series(gen, index=lrange(10, 20))
        exp.index = lrange(10, 20)
        assert_series_equal(result, exp)

    def test_constructor_map(self):
        # GH8909
        m = map(lambda x: x, range(10))

        result = Series(m)
        exp = Series(lrange(10))
        assert_series_equal(result, exp)

        m = map(lambda x: x, range(10))
        result = Series(m, index=lrange(10, 20))
        exp.index = lrange(10, 20)
        assert_series_equal(result, exp)

    def test_constructor_categorical(self):
        cat = pd.Categorical([0, 1, 2, 0, 1, 2], ['a', 'b', 'c'],
                             fastpath=True)
        res = Series(cat)
        tm.assert_categorical_equal(res.values, cat)

        # GH12574
        self.assertRaises(
            ValueError, lambda: Series(pd.Categorical([1, 2, 3]),
                                       dtype='int64'))
        cat = Series(pd.Categorical([1, 2, 3]), dtype='category')
        self.assertTrue(is_categorical_dtype(cat))
        self.assertTrue(is_categorical_dtype(cat.dtype))
        s = Series([1, 2, 3], dtype='category')
        self.assertTrue(is_categorical_dtype(s))
        self.assertTrue(is_categorical_dtype(s.dtype))

    def test_constructor_maskedarray(self):
        data = ma.masked_all((3, ), dtype=float)
        result = Series(data)
        expected = Series([nan, nan, nan])
        assert_series_equal(result, expected)

        data[0] = 0.0
        data[2] = 2.0
        index = ['a', 'b', 'c']
        result = Series(data, index=index)
        expected = Series([0.0, nan, 2.0], index=index)
        assert_series_equal(result, expected)

        data[1] = 1.0
        result = Series(data, index=index)
        expected = Series([0.0, 1.0, 2.0], index=index)
        assert_series_equal(result, expected)

        data = ma.masked_all((3, ), dtype=int)
        result = Series(data)
        expected = Series([nan, nan, nan], dtype=float)
        assert_series_equal(result, expected)

        data[0] = 0
        data[2] = 2
        index = ['a', 'b', 'c']
        result = Series(data, index=index)
        expected = Series([0, nan, 2], index=index, dtype=float)
        assert_series_equal(result, expected)

        data[1] = 1
        result = Series(data, index=index)
        expected = Series([0, 1, 2], index=index, dtype=int)
        assert_series_equal(result, expected)

        data = ma.masked_all((3, ), dtype=bool)
        result = Series(data)
        expected = Series([nan, nan, nan], dtype=object)
        assert_series_equal(result, expected)

        data[0] = True
        data[2] = False
        index = ['a', 'b', 'c']
        result = Series(data, index=index)
        expected = Series([True, nan, False], index=index, dtype=object)
        assert_series_equal(result, expected)

        data[1] = True
        result = Series(data, index=index)
        expected = Series([True, True, False], index=index, dtype=bool)
        assert_series_equal(result, expected)

        from pandas import tslib
        data = ma.masked_all((3, ), dtype='M8[ns]')
        result = Series(data)
        expected = Series([tslib.iNaT, tslib.iNaT, tslib.iNaT], dtype='M8[ns]')
        assert_series_equal(result, expected)

        data[0] = datetime(2001, 1, 1)
        data[2] = datetime(2001, 1, 3)
        index = ['a', 'b', 'c']
        result = Series(data, index=index)
        expected = Series([datetime(2001, 1, 1), tslib.iNaT,
                           datetime(2001, 1, 3)], index=index, dtype='M8[ns]')
        assert_series_equal(result, expected)

        data[1] = datetime(2001, 1, 2)
        result = Series(data, index=index)
        expected = Series([datetime(2001, 1, 1), datetime(2001, 1, 2),
                           datetime(2001, 1, 3)], index=index, dtype='M8[ns]')
        assert_series_equal(result, expected)

    def test_constructor_default_index(self):
        s = Series([0, 1, 2])
        tm.assert_index_equal(s.index, pd.Index(np.arange(3)))

    def test_constructor_corner(self):
        df = tm.makeTimeDataFrame()
        objs = [df, df]
        s = Series(objs, index=[0, 1])
        tm.assertIsInstance(s, Series)

    def test_constructor_sanitize(self):
        s = Series(np.array([1., 1., 8.]), dtype='i8')
        self.assertEqual(s.dtype, np.dtype('i8'))

        s = Series(np.array([1., 1., np.nan]), copy=True, dtype='i8')
        self.assertEqual(s.dtype, np.dtype('f8'))

    def test_constructor_pass_none(self):
        s = Series(None, index=lrange(5))
        self.assertEqual(s.dtype, np.float64)

        s = Series(None, index=lrange(5), dtype=object)
        self.assertEqual(s.dtype, np.object_)

        # GH 7431
        # inference on the index
        s = Series(index=np.array([None]))
        expected = Series(index=Index([None]))
        assert_series_equal(s, expected)

    def test_constructor_pass_nan_nat(self):
        # GH 13467
        exp = Series([np.nan, np.nan], dtype=np.float64)
        self.assertEqual(exp.dtype, np.float64)
        tm.assert_series_equal(Series([np.nan, np.nan]), exp)
        tm.assert_series_equal(Series(np.array([np.nan, np.nan])), exp)

        exp = Series([pd.NaT, pd.NaT])
        self.assertEqual(exp.dtype, 'datetime64[ns]')
        tm.assert_series_equal(Series([pd.NaT, pd.NaT]), exp)
        tm.assert_series_equal(Series(np.array([pd.NaT, pd.NaT])), exp)

        tm.assert_series_equal(Series([pd.NaT, np.nan]), exp)
        tm.assert_series_equal(Series(np.array([pd.NaT, np.nan])), exp)

        tm.assert_series_equal(Series([np.nan, pd.NaT]), exp)
        tm.assert_series_equal(Series(np.array([np.nan, pd.NaT])), exp)

    def test_constructor_cast(self):
        self.assertRaises(ValueError, Series, ['a', 'b', 'c'], dtype=float)

    def test_constructor_dtype_nocast(self):
        # 1572
        s = Series([1, 2, 3])

        s2 = Series(s, dtype=np.int64)

        s2[1] = 5
        self.assertEqual(s[1], 5)

    def test_constructor_datelike_coercion(self):

        # GH 9477
        # incorrectly infering on dateimelike looking when object dtype is
        # specified
        s = Series([Timestamp('20130101'), 'NOV'], dtype=object)
        self.assertEqual(s.iloc[0], Timestamp('20130101'))
        self.assertEqual(s.iloc[1], 'NOV')
        self.assertTrue(s.dtype == object)

        # the dtype was being reset on the slicing and re-inferred to datetime
        # even thought the blocks are mixed
        belly = '216 3T19'.split()
        wing1 = '2T15 4H19'.split()
        wing2 = '416 4T20'.split()
        mat = pd.to_datetime('2016-01-22 2019-09-07'.split())
        df = pd.DataFrame(
            {'wing1': wing1,
             'wing2': wing2,
             'mat': mat}, index=belly)

        result = df.loc['3T19']
        self.assertTrue(result.dtype == object)
        result = df.loc['216']
        self.assertTrue(result.dtype == object)

    def test_constructor_dtype_datetime64(self):
        import pandas.tslib as tslib

        s = Series(tslib.iNaT, dtype='M8[ns]', index=lrange(5))
        self.assertTrue(isnull(s).all())

        # in theory this should be all nulls, but since
        # we are not specifying a dtype is ambiguous
        s = Series(tslib.iNaT, index=lrange(5))
        self.assertFalse(isnull(s).all())

        s = Series(nan, dtype='M8[ns]', index=lrange(5))
        self.assertTrue(isnull(s).all())

        s = Series([datetime(2001, 1, 2, 0, 0), tslib.iNaT], dtype='M8[ns]')
        self.assertTrue(isnull(s[1]))
        self.assertEqual(s.dtype, 'M8[ns]')

        s = Series([datetime(2001, 1, 2, 0, 0), nan], dtype='M8[ns]')
        self.assertTrue(isnull(s[1]))
        self.assertEqual(s.dtype, 'M8[ns]')

        # GH3416
        dates = [
            np.datetime64(datetime(2013, 1, 1)),
            np.datetime64(datetime(2013, 1, 2)),
            np.datetime64(datetime(2013, 1, 3)),
        ]

        s = Series(dates)
        self.assertEqual(s.dtype, 'M8[ns]')

        s.ix[0] = np.nan
        self.assertEqual(s.dtype, 'M8[ns]')

        # invalid astypes
        for t in ['s', 'D', 'us', 'ms']:
            self.assertRaises(TypeError, s.astype, 'M8[%s]' % t)

        # GH3414 related
        self.assertRaises(TypeError, lambda x: Series(
            Series(dates).astype('int') / 1000000, dtype='M8[ms]'))
        self.assertRaises(TypeError,
                          lambda x: Series(dates, dtype='datetime64'))

        # invalid dates can be help as object
        result = Series([datetime(2, 1, 1)])
        self.assertEqual(result[0], datetime(2, 1, 1, 0, 0))

        result = Series([datetime(3000, 1, 1)])
        self.assertEqual(result[0], datetime(3000, 1, 1, 0, 0))

        # don't mix types
        result = Series([Timestamp('20130101'), 1], index=['a', 'b'])
        self.assertEqual(result['a'], Timestamp('20130101'))
        self.assertEqual(result['b'], 1)

        # GH6529
        # coerce datetime64 non-ns properly
        dates = date_range('01-Jan-2015', '01-Dec-2015', freq='M')
        values2 = dates.view(np.ndarray).astype('datetime64[ns]')
        expected = Series(values2, dates)

        for dtype in ['s', 'D', 'ms', 'us', 'ns']:
            values1 = dates.view(np.ndarray).astype('M8[{0}]'.format(dtype))
            result = Series(values1, dates)
            assert_series_equal(result, expected)

        # leave datetime.date alone
        dates2 = np.array([d.date() for d in dates.to_pydatetime()],
                          dtype=object)
        series1 = Series(dates2, dates)
        self.assert_numpy_array_equal(series1.values, dates2)
        self.assertEqual(series1.dtype, object)

        # these will correctly infer a datetime
        s = Series([None, pd.NaT, '2013-08-05 15:30:00.000001'])
        self.assertEqual(s.dtype, 'datetime64[ns]')
        s = Series([np.nan, pd.NaT, '2013-08-05 15:30:00.000001'])
        self.assertEqual(s.dtype, 'datetime64[ns]')
        s = Series([pd.NaT, None, '2013-08-05 15:30:00.000001'])
        self.assertEqual(s.dtype, 'datetime64[ns]')
        s = Series([pd.NaT, np.nan, '2013-08-05 15:30:00.000001'])
        self.assertEqual(s.dtype, 'datetime64[ns]')

        # tz-aware (UTC and other tz's)
        # GH 8411
        dr = date_range('20130101', periods=3)
        self.assertTrue(Series(dr).iloc[0].tz is None)
        dr = date_range('20130101', periods=3, tz='UTC')
        self.assertTrue(str(Series(dr).iloc[0].tz) == 'UTC')
        dr = date_range('20130101', periods=3, tz='US/Eastern')
        self.assertTrue(str(Series(dr).iloc[0].tz) == 'US/Eastern')

        # non-convertible
        s = Series([1479596223000, -1479590, pd.NaT])
        self.assertTrue(s.dtype == 'object')
        self.assertTrue(s[2] is pd.NaT)
        self.assertTrue('NaT' in str(s))

        # if we passed a NaT it remains
        s = Series([datetime(2010, 1, 1), datetime(2, 1, 1), pd.NaT])
        self.assertTrue(s.dtype == 'object')
        self.assertTrue(s[2] is pd.NaT)
        self.assertTrue('NaT' in str(s))

        # if we passed a nan it remains
        s = Series([datetime(2010, 1, 1), datetime(2, 1, 1), np.nan])
        self.assertTrue(s.dtype == 'object')
        self.assertTrue(s[2] is np.nan)
        self.assertTrue('NaN' in str(s))

    def test_constructor_with_datetime_tz(self):

        # 8260
        # support datetime64 with tz

        dr = date_range('20130101', periods=3, tz='US/Eastern')
        s = Series(dr)
        self.assertTrue(s.dtype.name == 'datetime64[ns, US/Eastern]')
        self.assertTrue(s.dtype == 'datetime64[ns, US/Eastern]')
        self.assertTrue(is_datetime64tz_dtype(s.dtype))
        self.assertTrue('datetime64[ns, US/Eastern]' in str(s))

        # export
        result = s.values
        self.assertIsInstance(result, np.ndarray)
        self.assertTrue(result.dtype == 'datetime64[ns]')

        exp = pd.DatetimeIndex(result)
        exp = exp.tz_localize('UTC').tz_convert(tz=s.dt.tz)
        self.assert_index_equal(dr, exp)

        # indexing
        result = s.iloc[0]
        self.assertEqual(result, Timestamp('2013-01-01 00:00:00-0500',
                                           tz='US/Eastern', freq='D'))
        result = s[0]
        self.assertEqual(result, Timestamp('2013-01-01 00:00:00-0500',
                                           tz='US/Eastern', freq='D'))

        result = s[Series([True, True, False], index=s.index)]
        assert_series_equal(result, s[0:2])

        result = s.iloc[0:1]
        assert_series_equal(result, Series(dr[0:1]))

        # concat
        result = pd.concat([s.iloc[0:1], s.iloc[1:]])
        assert_series_equal(result, s)

        # astype
        result = s.astype(object)
        expected = Series(DatetimeIndex(s._values).asobject)
        assert_series_equal(result, expected)

        result = Series(s.values).dt.tz_localize('UTC').dt.tz_convert(s.dt.tz)
        assert_series_equal(result, s)

        # astype - datetime64[ns, tz]
        result = Series(s.values).astype('datetime64[ns, US/Eastern]')
        assert_series_equal(result, s)

        result = Series(s.values).astype(s.dtype)
        assert_series_equal(result, s)

        result = s.astype('datetime64[ns, CET]')
        expected = Series(date_range('20130101 06:00:00', periods=3, tz='CET'))
        assert_series_equal(result, expected)

        # short str
        self.assertTrue('datetime64[ns, US/Eastern]' in str(s))

        # formatting with NaT
        result = s.shift()
        self.assertTrue('datetime64[ns, US/Eastern]' in str(result))
        self.assertTrue('NaT' in str(result))

        # long str
        t = Series(date_range('20130101', periods=1000, tz='US/Eastern'))
        self.assertTrue('datetime64[ns, US/Eastern]' in str(t))

        result = pd.DatetimeIndex(s, freq='infer')
        tm.assert_index_equal(result, dr)

        # inference
        s = Series([pd.Timestamp('2013-01-01 13:00:00-0800', tz='US/Pacific'),
                    pd.Timestamp('2013-01-02 14:00:00-0800', tz='US/Pacific')])
        self.assertTrue(s.dtype == 'datetime64[ns, US/Pacific]')
        self.assertTrue(lib.infer_dtype(s) == 'datetime64')

        s = Series([pd.Timestamp('2013-01-01 13:00:00-0800', tz='US/Pacific'),
                    pd.Timestamp('2013-01-02 14:00:00-0800', tz='US/Eastern')])
        self.assertTrue(s.dtype == 'object')
        self.assertTrue(lib.infer_dtype(s) == 'datetime')

        # with all NaT
        s = Series(pd.NaT, index=[0, 1], dtype='datetime64[ns, US/Eastern]')
        expected = Series(pd.DatetimeIndex(['NaT', 'NaT'], tz='US/Eastern'))
        assert_series_equal(s, expected)

    def test_constructor_periodindex(self):
        # GH7932
        # converting a PeriodIndex when put in a Series

        pi = period_range('20130101', periods=5, freq='D')
        s = Series(pi)
        expected = Series(pi.asobject)
        assert_series_equal(s, expected)

        self.assertEqual(s.dtype, 'object')

    def test_constructor_dict(self):
        d = {'a': 0., 'b': 1., 'c': 2.}
        result = Series(d, index=['b', 'c', 'd', 'a'])
        expected = Series([1, 2, nan, 0], index=['b', 'c', 'd', 'a'])
        assert_series_equal(result, expected)

        pidx = tm.makePeriodIndex(100)
        d = {pidx[0]: 0, pidx[1]: 1}
        result = Series(d, index=pidx)
        expected = Series(np.nan, pidx)
        expected.ix[0] = 0
        expected.ix[1] = 1
        assert_series_equal(result, expected)

    def test_constructor_dict_multiindex(self):
        check = lambda result, expected: tm.assert_series_equal(
            result, expected, check_dtype=True, check_series_type=True)
        d = {('a', 'a'): 0., ('b', 'a'): 1., ('b', 'c'): 2.}
        _d = sorted(d.items())
        ser = Series(d)
        expected = Series([x[1] for x in _d],
                          index=MultiIndex.from_tuples([x[0] for x in _d]))
        check(ser, expected)

        d['z'] = 111.
        _d.insert(0, ('z', d['z']))
        ser = Series(d)
        expected = Series([x[1] for x in _d], index=Index(
            [x[0] for x in _d], tupleize_cols=False))
        ser = ser.reindex(index=expected.index)
        check(ser, expected)

    def test_constructor_dict_timedelta_index(self):
        # GH #12169 : Resample category data with timedelta index
        # construct Series from dict as data and TimedeltaIndex as index
        # will result NaN in result Series data
        expected = Series(
            data=['A', 'B', 'C'],
            index=pd.to_timedelta([0, 10, 20], unit='s')
        )

        result = Series(
            data={pd.to_timedelta(0, unit='s'): 'A',
                  pd.to_timedelta(10, unit='s'): 'B',
                  pd.to_timedelta(20, unit='s'): 'C'},
            index=pd.to_timedelta([0, 10, 20], unit='s')
        )
        # this should work
        assert_series_equal(result, expected)

    def test_constructor_subclass_dict(self):
        data = tm.TestSubDict((x, 10.0 * x) for x in range(10))
        series = Series(data)
        refseries = Series(dict(compat.iteritems(data)))
        assert_series_equal(refseries, series)

    def test_constructor_dict_datetime64_index(self):
        # GH 9456

        dates_as_str = ['1984-02-19', '1988-11-06', '1989-12-03', '1990-03-15']
        values = [42544017.198965244, 1234565, 40512335.181958228, -1]

        def create_data(constructor):
            return dict(zip((constructor(x) for x in dates_as_str), values))

        data_datetime64 = create_data(np.datetime64)
        data_datetime = create_data(lambda x: datetime.strptime(x, '%Y-%m-%d'))
        data_Timestamp = create_data(Timestamp)

        expected = Series(values, (Timestamp(x) for x in dates_as_str))

        result_datetime64 = Series(data_datetime64)
        result_datetime = Series(data_datetime)
        result_Timestamp = Series(data_Timestamp)

        assert_series_equal(result_datetime64, expected)
        assert_series_equal(result_datetime, expected)
        assert_series_equal(result_Timestamp, expected)

    def test_orderedDict_ctor(self):
        # GH3283
        import pandas
        import random
        data = OrderedDict([('col%s' % i, random.random()) for i in range(12)])
        s = pandas.Series(data)
        self.assertTrue(all(s.values == list(data.values())))

    def test_orderedDict_subclass_ctor(self):
        # GH3283
        import pandas
        import random

        class A(OrderedDict):
            pass

        data = A([('col%s' % i, random.random()) for i in range(12)])
        s = pandas.Series(data)
        self.assertTrue(all(s.values == list(data.values())))

    def test_constructor_list_of_tuples(self):
        data = [(1, 1), (2, 2), (2, 3)]
        s = Series(data)
        self.assertEqual(list(s), data)

    def test_constructor_tuple_of_tuples(self):
        data = ((1, 1), (2, 2), (2, 3))
        s = Series(data)
        self.assertEqual(tuple(s), data)

    def test_constructor_set(self):
        values = set([1, 2, 3, 4, 5])
        self.assertRaises(TypeError, Series, values)
        values = frozenset(values)
        self.assertRaises(TypeError, Series, values)

    def test_fromDict(self):
        data = {'a': 0, 'b': 1, 'c': 2, 'd': 3}

        series = Series(data)
        self.assertTrue(tm.is_sorted(series.index))

        data = {'a': 0, 'b': '1', 'c': '2', 'd': datetime.now()}
        series = Series(data)
        self.assertEqual(series.dtype, np.object_)

        data = {'a': 0, 'b': '1', 'c': '2', 'd': '3'}
        series = Series(data)
        self.assertEqual(series.dtype, np.object_)

        data = {'a': '0', 'b': '1'}
        series = Series(data, dtype=float)
        self.assertEqual(series.dtype, np.float64)

    def test_fromValue(self):

        nans = Series(np.NaN, index=self.ts.index)
        self.assertEqual(nans.dtype, np.float_)
        self.assertEqual(len(nans), len(self.ts))

        strings = Series('foo', index=self.ts.index)
        self.assertEqual(strings.dtype, np.object_)
        self.assertEqual(len(strings), len(self.ts))

        d = datetime.now()
        dates = Series(d, index=self.ts.index)
        self.assertEqual(dates.dtype, 'M8[ns]')
        self.assertEqual(len(dates), len(self.ts))

        # GH12336
        # Test construction of categorical series from value
        categorical = Series(0, index=self.ts.index, dtype="category")
        expected = Series(0, index=self.ts.index).astype("category")
        self.assertEqual(categorical.dtype, 'category')
        self.assertEqual(len(categorical), len(self.ts))
        tm.assert_series_equal(categorical, expected)

    def test_constructor_dtype_timedelta64(self):

        # basic
        td = Series([timedelta(days=i) for i in range(3)])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([timedelta(days=1)])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([timedelta(days=1), timedelta(days=2), np.timedelta64(
            1, 's')])

        self.assertEqual(td.dtype, 'timedelta64[ns]')

        # mixed with NaT
        from pandas import tslib
        td = Series([timedelta(days=1), tslib.NaT], dtype='m8[ns]')
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([timedelta(days=1), np.nan], dtype='m8[ns]')
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([np.timedelta64(300000000), pd.NaT], dtype='m8[ns]')
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        # improved inference
        # GH5689
        td = Series([np.timedelta64(300000000), pd.NaT])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        # because iNaT is int, not coerced to timedelta
        td = Series([np.timedelta64(300000000), tslib.iNaT])
        self.assertEqual(td.dtype, 'object')

        td = Series([np.timedelta64(300000000), np.nan])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([pd.NaT, np.timedelta64(300000000)])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        td = Series([np.timedelta64(1, 's')])
        self.assertEqual(td.dtype, 'timedelta64[ns]')

        # these are frequency conversion astypes
        # for t in ['s', 'D', 'us', 'ms']:
        #    self.assertRaises(TypeError, td.astype, 'm8[%s]' % t)

        # valid astype
        td.astype('int64')

        # invalid casting
        self.assertRaises(TypeError, td.astype, 'int32')

        # this is an invalid casting
        def f():
            Series([timedelta(days=1), 'foo'], dtype='m8[ns]')

        self.assertRaises(Exception, f)

        # leave as object here
        td = Series([timedelta(days=i) for i in range(3)] + ['foo'])
        self.assertEqual(td.dtype, 'object')

        # these will correctly infer a timedelta
        s = Series([None, pd.NaT, '1 Day'])
        self.assertEqual(s.dtype, 'timedelta64[ns]')
        s = Series([np.nan, pd.NaT, '1 Day'])
        self.assertEqual(s.dtype, 'timedelta64[ns]')
        s = Series([pd.NaT, None, '1 Day'])
        self.assertEqual(s.dtype, 'timedelta64[ns]')
        s = Series([pd.NaT, np.nan, '1 Day'])
        self.assertEqual(s.dtype, 'timedelta64[ns]')

    def test_constructor_name_hashable(self):
        for n in [777, 777., 'name', datetime(2001, 11, 11), (1, ), u"\u05D0"]:
            for data in [[1, 2, 3], np.ones(3), {'a': 0, 'b': 1}]:
                s = Series(data, name=n)
                self.assertEqual(s.name, n)

    def test_constructor_name_unhashable(self):
        for n in [['name_list'], np.ones(2), {1: 2}]:
            for data in [['name_list'], np.ones(2), {1: 2}]:
                self.assertRaises(TypeError, Series, data, name=n)