from sklearn.cross_validation import KFold
n_samples = 200
cv = KFold(n=n_samples, n_folds=5)

%matplotlib inline
import numpy as np
import matplotlib.pyplot as plt

for training_set, test_set in cv:
    plt.figure(figsize=(20,1))
    plt.plot(training_set, np.ones(len(training_set)), "o", color='blue', label="training set")
    plt.plot(test_set, np.ones(len(test_set)), "o", color='red', label="test set")
    plt.legend(loc="best")
    plt.axis("off")

from sklearn.cross_validation import cross_val_score, train_test_split

from sklearn.datasets import load_digits

digits = load_digits()

X_train, X_test, y_train, y_test = train_test_split(digits.data, digits.target)

from sklearn.svm import SVC

cross_val_score(SVC(C=1), X_train, y_train, cv=3)

cross_val_score(SVC(C=10), X_train, y_train, cv=3, scoring="f1")

cross_val_score(SVC(C=10), X_train, y_train % 2, cv=3)

cross_val_score(SVC(C=10), X_train, y_train % 2, cv=3, scoring="average_precision")

cross_val_score(SVC(C=10), X_train, y_train % 2, cv=3, scoring="roc_auc")

from sklearn.cross_validation import ShuffleSplit
cross_val_score(SVC(C=10), X_train, y_train, cv=ShuffleSplit(len(X_train), 10, test_size=.4))