test_alter_axes.py

from datetime import datetime

import numpy as np
import pytest

from pandas import DataFrame, Index, MultiIndex, RangeIndex, Series
import pandas.util.testing as tm


class TestSeriesAlterAxes:
    def test_setindex(self, string_series):
        # wrong type
        msg = (
            r"Index\(\.\.\.\) must be called with a collection of some"
            r" kind, None was passed"
        )
        with pytest.raises(TypeError, match=msg):
            string_series.index = None

        # wrong length
        msg = (
            "Length mismatch: Expected axis has 30 elements, new"
            " values have 29 elements"
        )
        with pytest.raises(ValueError, match=msg):
            string_series.index = np.arange(len(string_series) - 1)

        # works
        string_series.index = np.arange(len(string_series))
        assert isinstance(string_series.index, Index)

    # Renaming

    def test_rename(self, datetime_series):
        ts = datetime_series
        renamer = lambda x: x.strftime("%Y%m%d")
        renamed = ts.rename(renamer)
        assert renamed.index[0] == renamer(ts.index[0])

        # dict
        rename_dict = dict(zip(ts.index, renamed.index))
        renamed2 = ts.rename(rename_dict)
        tm.assert_series_equal(renamed, renamed2)

        # partial dict
        s = Series(np.arange(4), index=["a", "b", "c", "d"], dtype="int64")
        renamed = s.rename({"b": "foo", "d": "bar"})
        tm.assert_index_equal(renamed.index, Index(["a", "foo", "c", "bar"]))

        # index with name
        renamer = Series(
            np.arange(4), index=Index(["a", "b", "c", "d"], name="name"), dtype="int64"
        )
        renamed = renamer.rename({})
        assert renamed.index.name == renamer.index.name

    def test_rename_by_series(self):
        s = Series(range(5), name="foo")
        renamer = Series({1: 10, 2: 20})
        result = s.rename(renamer)
        expected = Series(range(5), index=[0, 10, 20, 3, 4], name="foo")
        tm.assert_series_equal(result, expected)

    def test_rename_set_name(self):
        s = Series(range(4), index=list("abcd"))
        for name in ["foo", 123, 123.0, datetime(2001, 11, 11), ("foo",)]:
            result = s.rename(name)
            assert result.name == name
            tm.assert_numpy_array_equal(result.index.values, s.index.values)
            assert s.name is None

    def test_rename_set_name_inplace(self):
        s = Series(range(3), index=list("abc"))
        for name in ["foo", 123, 123.0, datetime(2001, 11, 11), ("foo",)]:
            s.rename(name, inplace=True)
            assert s.name == name

            exp = np.array(["a", "b", "c"], dtype=np.object_)
            tm.assert_numpy_array_equal(s.index.values, exp)

    def test_rename_axis_supported(self):
        # Supporting axis for compatibility, detailed in GH-18589
        s = Series(range(5))
        s.rename({}, axis=0)
        s.rename({}, axis="index")
        with pytest.raises(ValueError, match="No axis named 5"):
            s.rename({}, axis=5)

    def test_set_name_attribute(self):
        s = Series([1, 2, 3])
        s2 = Series([1, 2, 3], name="bar")
        for name in [7, 7.0, "name", datetime(2001, 1, 1), (1,), "\u05D0"]:
            s.name = name
            assert s.name == name
            s2.name = name
            assert s2.name == name

    def test_set_name(self):
        s = Series([1, 2, 3])
        s2 = s._set_name("foo")
        assert s2.name == "foo"
        assert s.name is None
        assert s is not s2

    def test_rename_inplace(self, datetime_series):
        renamer = lambda x: x.strftime("%Y%m%d")
        expected = renamer(datetime_series.index[0])

        datetime_series.rename(renamer, inplace=True)
        assert datetime_series.index[0] == expected

    def test_set_index_makes_timeseries(self):
        idx = tm.makeDateIndex(10)

        s = Series(range(10))
        s.index = idx
        assert s.index.is_all_dates

    def test_reset_index(self):
        df = tm.makeDataFrame()[:5]
        ser = df.stack()
        ser.index.names = ["hash", "category"]

        ser.name = "value"
        df = ser.reset_index()
        assert "value" in df

        df = ser.reset_index(name="value2")
        assert "value2" in df

        # check inplace
        s = ser.reset_index(drop=True)
        s2 = ser
        s2.reset_index(drop=True, inplace=True)
        tm.assert_series_equal(s, s2)

        # level
        index = MultiIndex(
            levels=[["bar"], ["one", "two", "three"], [0, 1]],
            codes=[[0, 0, 0, 0, 0, 0], [0, 1, 2, 0, 1, 2], [0, 1, 0, 1, 0, 1]],
        )
        s = Series(np.random.randn(6), index=index)
        rs = s.reset_index(level=1)
        assert len(rs.columns) == 2

        rs = s.reset_index(level=[0, 2], drop=True)
        tm.assert_index_equal(rs.index, Index(index.get_level_values(1)))
        assert isinstance(rs, Series)

    def test_reset_index_name(self):
        s = Series([1, 2, 3], index=Index(range(3), name="x"))
        assert s.reset_index().index.name is None
        assert s.reset_index(drop=True).index.name is None

    def test_reset_index_level(self):
        df = DataFrame([[1, 2, 3], [4, 5, 6]], columns=["A", "B", "C"])

        for levels in ["A", "B"], [0, 1]:
            # With MultiIndex
            s = df.set_index(["A", "B"])["C"]

            result = s.reset_index(level=levels[0])
            tm.assert_frame_equal(result, df.set_index("B"))

            result = s.reset_index(level=levels[:1])
            tm.assert_frame_equal(result, df.set_index("B"))

            result = s.reset_index(level=levels)
            tm.assert_frame_equal(result, df)

            result = df.set_index(["A", "B"]).reset_index(level=levels, drop=True)
            tm.assert_frame_equal(result, df[["C"]])

            with pytest.raises(KeyError, match="Level E "):
                s.reset_index(level=["A", "E"])

            # With single-level Index
            s = df.set_index("A")["B"]

            result = s.reset_index(level=levels[0])
            tm.assert_frame_equal(result, df[["A", "B"]])

            result = s.reset_index(level=levels[:1])
            tm.assert_frame_equal(result, df[["A", "B"]])

            result = s.reset_index(level=levels[0], drop=True)
            tm.assert_series_equal(result, df["B"])

            with pytest.raises(IndexError, match="Too many levels"):
                s.reset_index(level=[0, 1, 2])

        # Check that .reset_index([],drop=True) doesn't fail
        result = Series(range(4)).reset_index([], drop=True)
        expected = Series(range(4))
        tm.assert_series_equal(result, expected)

    def test_reset_index_range(self):
        # GH 12071
        s = Series(range(2), name="A", dtype="int64")
        series_result = s.reset_index()
        assert isinstance(series_result.index, RangeIndex)
        series_expected = DataFrame(
            [[0, 0], [1, 1]], columns=["index", "A"], index=RangeIndex(stop=2)
        )
        tm.assert_frame_equal(series_result, series_expected)

    def test_reorder_levels(self):
        index = MultiIndex(
            levels=[["bar"], ["one", "two", "three"], [0, 1]],
            codes=[[0, 0, 0, 0, 0, 0], [0, 1, 2, 0, 1, 2], [0, 1, 0, 1, 0, 1]],
            names=["L0", "L1", "L2"],
        )
        s = Series(np.arange(6), index=index)

        # no change, position
        result = s.reorder_levels([0, 1, 2])
        tm.assert_series_equal(s, result)

        # no change, labels
        result = s.reorder_levels(["L0", "L1", "L2"])
        tm.assert_series_equal(s, result)

        # rotate, position
        result = s.reorder_levels([1, 2, 0])
        e_idx = MultiIndex(
            levels=[["one", "two", "three"], [0, 1], ["bar"]],
            codes=[[0, 1, 2, 0, 1, 2], [0, 1, 0, 1, 0, 1], [0, 0, 0, 0, 0, 0]],
            names=["L1", "L2", "L0"],
        )
        expected = Series(np.arange(6), index=e_idx)
        tm.assert_series_equal(result, expected)

    def test_rename_axis_mapper(self):
        # GH 19978
        mi = MultiIndex.from_product([["a", "b", "c"], [1, 2]], names=["ll", "nn"])
        s = Series([i for i in range(len(mi))], index=mi)

        result = s.rename_axis(index={"ll": "foo"})
        assert result.index.names == ["foo", "nn"]

        result = s.rename_axis(index=str.upper, axis=0)
        assert result.index.names == ["LL", "NN"]

        result = s.rename_axis(index=["foo", "goo"])
        assert result.index.names == ["foo", "goo"]

        with pytest.raises(TypeError, match="unexpected"):
            s.rename_axis(columns="wrong")

    def test_rename_axis_inplace(self, datetime_series):
        # GH 15704
        expected = datetime_series.rename_axis("foo")
        result = datetime_series
        no_return = result.rename_axis("foo", inplace=True)

        assert no_return is None
        tm.assert_series_equal(result, expected)

    @pytest.mark.parametrize("kwargs", [{"mapper": None}, {"index": None}, {}])
    def test_rename_axis_none(self, kwargs):
        # GH 25034
        index = Index(list("abc"), name="foo")
        df = Series([1, 2, 3], index=index)

        result = df.rename_axis(**kwargs)
        expected_index = index.rename(None) if kwargs else index
        expected = Series([1, 2, 3], index=expected_index)
        tm.assert_series_equal(result, expected)

    def test_set_axis_inplace_axes(self, axis_series):
        # GH14636
        ser = Series(np.arange(4), index=[1, 3, 5, 7], dtype="int64")

        expected = ser.copy()
        expected.index = list("abcd")

        # inplace=True
        # The FutureWarning comes from the fact that we would like to have
        # inplace default to False some day
        result = ser.copy()
        result.set_axis(list("abcd"), axis=axis_series, inplace=True)
        tm.assert_series_equal(result, expected)

    def test_set_axis_inplace(self):
        # GH14636

        s = Series(np.arange(4), index=[1, 3, 5, 7], dtype="int64")

        expected = s.copy()
        expected.index = list("abcd")

        # inplace=False
        result = s.set_axis(list("abcd"), axis=0, inplace=False)
        tm.assert_series_equal(expected, result)

        # omitting the "axis" parameter
        with tm.assert_produces_warning(None):
            result = s.set_axis(list("abcd"), inplace=False)
        tm.assert_series_equal(result, expected)

        # wrong values for the "axis" parameter
        for axis in [2, "foo"]:
            with pytest.raises(ValueError, match="No axis named"):
                s.set_axis(list("abcd"), axis=axis, inplace=False)

    def test_set_axis_prior_to_deprecation_signature(self):
        s = Series(np.arange(4), index=[1, 3, 5, 7], dtype="int64")

        expected = s.copy()
        expected.index = list("abcd")

        for axis in [0, "index"]:
            with tm.assert_produces_warning(FutureWarning):
                result = s.set_axis(0, list("abcd"), inplace=False)
            tm.assert_series_equal(result, expected)

    def test_reset_index_drop_errors(self):
        #  GH 20925

        # KeyError raised for series index when passed level name is missing
        s = Series(range(4))
        with pytest.raises(KeyError, match="must be same as name"):
            s.reset_index("wrong", drop=True)
        with pytest.raises(KeyError, match="must be same as name"):
            s.reset_index("wrong")

        # KeyError raised for series when level to be dropped is missing
        s = Series(range(4), index=MultiIndex.from_product([[1, 2]] * 2))
        with pytest.raises(KeyError, match="not found"):
            s.reset_index("wrong", drop=True)

    def test_droplevel(self):
        # GH20342
        ser = Series([1, 2, 3, 4])
        ser.index = MultiIndex.from_arrays(
            [(1, 2, 3, 4), (5, 6, 7, 8)], names=["a", "b"]
        )
        expected = ser.reset_index("b", drop=True)
        result = ser.droplevel("b", axis="index")
        tm.assert_series_equal(result, expected)
        # test that droplevel raises ValueError on axis != 0
        with pytest.raises(ValueError):
            ser.droplevel(1, axis="columns")