title: how to give the test size in stratified kfold sampling in python?
body: <p>Using sklearn , I want to have 3 splits (i.e. n_splits = 3)in the sample dataset and have a Train/Test ratio as 70:30. I'm able split the set into 3 folds but not able to define the test size (similar to train_test_split method).Is there a way to do define test sample size in StratifiedKFold ?</p>
  
  <pre><code>from sklearn.model_selection import StratifiedKFold as SKF
  skf = SKF(n_splits=3)
  skf.get_n_splits(X, y)
  for train_index, test_index in skf.split(X, y):
  # Loops over 3 iterations to have Train test stratified split
       X_train, X_test = X[train_index], X[test_index]
       y_train, y_test = y[train_index], y[test_index]
  </code></pre>