test_categorical.py 文件源码

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)