机器学习之独热编码

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• 机器学习之独热编码

# -*- coding: utf-8 -*-
"""
Created on Sat Dec  8 15:12:29 2018

@author: muli
"""

from sklearn.preprocessing import OneHotEncoder

def test_OneHotEncoder():
    '''
    测试 OneHotEncoder 的用法

    :return: None
    '''
    X=[   [1,2,3,4,5],
          [5,4,3,2,1],
          [3,3,3,3,3,],
          [1,1,1,1,1] ]
    print("before transform:",X)
    encoder=OneHotEncoder(sparse=False)
    # 没有解释清楚
#    encoder=OneHotEncoder(sparse=True)
    encoder.fit(X)
    print("active_features_:",encoder.active_features_)
    print("feature_indices_:",encoder.feature_indices_)
    print("n_values_:",encoder.n_values_)
    print("-----------------------")
    print("after transform:",encoder.transform([[1,2,3,4,5]]))
    print("-----------------------")
#    print("after transform:",encoder.transform([[1,1,1,1,1]]))
    print("after transform2:",encoder.transform(X))
    print("***********************")
    # [[1,1,1,1,1]] 没有用处
    print("after transform3:",encoder.fit_transform(X,[[1,1,1,1,1]]))

    
if __name__=='__main__':
    test_OneHotEncoder() # 调用 test_OneHotEncoder