1>>> from sklearn.feature_selection import SelectKBest, chi2
2>>> from sklearn.datasets import load_wine
3>>> X,y = load_wine(return_X_y=True,as_frame=True)
4>>> print(X.shape)
5(178, 13)
6
7>>> print(X.columns)
8['alcohol', 'malic_acid', 'ash', 'alcalinity_of_ash', 'magnesium',
9↪ 'total_phenols', 'flavanoids', 'nonflavanoid_phenols',
10↪ 'proanthocyanins', 'color_intensity', 'hue',
11↪ 'od280/od315_of_diluted_wines', 'proline']
12
13>>> skb = SelectKBest(chi2, k=3)
14>>> X_selected = skb.fit_transform(X, y)
15
16>>> print(skb.scores_)
17[5.44, 28.06, 0.74, 29.38, 45.02, 15.62, 63.33, 1.81, 9.36, 109.01, 5.18,
18↪ 23.38, 16540.06]
19
20>>> print(skb.pvalues_)
21[6.56e-02, 8.03e-07, 0.68, 4.16e-07, 1.66e-10, 4.05e-04, 1.76e-14, 0.40,
22↪ 9.24e-03, 2.12e-24, 0.074, 8.33e-06, 0]
23
24>>> print(skb.pvalues_.argsort())
25[12, 9, 6, 4, 3, 1, 11, 5, 8, 0, 10, 7, 2]