import numpy as np from sklearn import datasets from sklearn.model_selection import train_test_split from sklearn.preprocessing import StandardScaler iris = datasets.load_iris() X = iris.data y = iris.target X_train,X_test,y_train,y_test = train_test_split(X,y,test_size= 0.2,random_state=666) standardScaler = StandardScaler() standardScaler.fit(X_train) standardScaler.mean_ #mean standardScaler.scale_ #variance X_train = standardScaler.transform(X_train) #normalization X_test_standerd = standardScaler.transform(X_test) #test dataset normalization from sklearn.neighbors import KNeighborsClassifier KNN_classifier = KNeighborsClassifier(n_neighbors=3) KNN_classifier.fit(X_train,y_train) KNN_classifier.score(X_test_standerd,y_test)