title: scikit-learn random state in splitting dataset
body: <p>Can anyone tell me why we set random state to zero in splitting train and test set.</p>
  <pre><code>X_train, X_test, y_train, y_test = \
      train_test_split(X, y, test_size=0.30, random_state=0)
  </code></pre>
  <p>I have seen situations like this where random state is set to 1!</p>
  <pre><code>X_train, X_test, y_train, y_test = \
      train_test_split(X, y, test_size=0.30, random_state=1)
  </code></pre>
  <p>What is the consequence of this random state in cross validation as well?</p>