Intercept column does not work properly with truncated indexes

[janmotl]

Intercept column sometimes contains nan:

    def test_truncated_index(self):
        data = pd.DataFrame(data={'x': ['A', 'B', 'C', 'A', 'B'], 'y': [1, 0, 1, 0, 1]})
        data = data.iloc[2:5]
        data2 = pd.DataFrame(data={'x': ['C', 'A', 'B'], 'y': [1, 0, 1]})
        for encoder_name in encoders.__all__:
            with self.subTest(encoder_name=encoder_name):
                enc = getattr(encoders, encoder_name)()
                result = enc.fit_transform(data.x, data.y)
                enc2 = getattr(encoders, encoder_name)()
                result2 = enc2.fit_transform(data2.x, data2.y)
                self.assertTrue((result.values == result2.values).all())

[janmotl]

Solved by @JohnnyC08 . Added test into test_encoders.