code: def test_pandas_index(self):
      # see https://github.com/scikit-learn-contrib/categorical-encoding/pull/224
      df = pd.DataFrame(
          {"hello": ["a", "b", "c"], "world": [0, 1, 0]},
          columns=pd.Index(["hello", "world"]),
      )
      cols = df.select_dtypes(include="object").columns
  
      for encoder_name in set(encoders.__all__) - {"HashingEncoder"}:
          with self.subTest(encoder_name=encoder_name):
              enc = getattr(encoders, encoder_name)(cols=cols)
              enc.fit_transform(df, df["world"])
  
imports: import warnings
  from datetime import timedelta
  import numpy
  from numpy.testing import assert_array_equal
  import pandas
  import sklearn
  import tests.helpers
  from sklearn.utils.estimator_checks import check_transformer_general, check_transformers_unfitted, check_n_features_in
  from sklearn.compose import ColumnTransformer
  from unittest import TestCase
  from copy import deepcopy
  import category_encoders
label_desc: Use image node_id 40 for calling the TestEncoders obj's underlying member method code with example usage: obj.test_pandas_index() without return types