test_categorical.py 文件源码

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)