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scikit-learncategoriesencoderordinal

AttributeError: 'OrdinalEncoder' object has no attribute 'category_mapping'

When I use the following function, I get the AttributeError.

from category_encoders import OrdinalEncoder

def label_encode(input_data, col):
    name = col +'_encoded'
    encoder = OrdinalEncoder(return_df=True, handle_unknown='ignore')
    input_data[name] = encoder.fit_transform(input_data[col].values).values - 1
    encoder = dict(encoder.category_mapping[0]['mapping'])
    return input_data, encoder, name
Solution

  • Could you check if category_mapping shows up when you run dir(encoder) if it does not appears in the list you might be using the sklearn version of the encoder instead of the scikit-learn-contrib OrdinalEncoder.

    When I run the dir(encoder) command the category_mapping attribute appears:

    [ ...
 'category_mapping',
 'cols',
 'drop_cols',
 'drop_invariant',
 'feature_names',
 'fit',
 'fit_transform',
 'get_feature_names',
 'get_params',
 'handle_missing',
 'handle_unknown',
 'inverse_transform',
 'mapping',
 'ordinal_encoding',
 'return_df',
 'set_params',
 'transform',
 'verbose']

    If you run this snippet it should display the mapping:

    from category_encoders import *
import pandas as pd
from sklearn.datasets import load_boston
bunch = load_boston()
y = bunch.target
X = pd.DataFrame(bunch.data, columns=bunch.feature_names)
enc = OrdinalEncoder(cols=['CHAS', 'RAD']).fit(X, y)
numeric_dataset = enc.transform(X)
enc.category_mapping[0]['mapping']

    0.0    1
1.0    2
NaN   -2
dtype: int64