title: how can I overcome on this problem X_train, X_test, Y_train, Y_test = train_test_split(X, Y, test_size=0.25, stratify=Y, random_state=2)
body: <pre><code>X_train, X_test, Y_train, Y_test = train_test_split(X, Y, test_size=0.25, stratify=Y, random_state=2)
  
  ValueError: The least populated class in y has only 1 member, which is too few. 
  The minimum number of groups for any class cannot be less than 2.
  </code></pre>