module 'sklearn' has no attribute 'cross_validation'
sklearn does not automatically import its subpackages. If you only imported via: import sklearn, then it won't work. Import with import sklearn.cross_validation instead.
Further, sklearn.cross_validation will be deprecated in version 0.20. Use sklearn.model_selection.train_test_split instead.
Try this:
from sklearn.model_selection import train_test_splitX_train, X_test, Y_train, Y_test = train_test_split(X, Y, test_size=0.33, random_state=101)
The equivalent to cross_validation in sklearn is:
sklearn.model_selection