title: UserWarning: One or more of the test scores are non-finite
body: <p>I'm a relatively new user to python and have question about warning. I have dataframe that has shape of (96350, 156). With that I am building my decison tree model and using grid search cross validation. Why I am getting that output and how can I solve it?</p>
  <p>Input:</p>
  <pre><code>grid_param = {
      'criterion': ['squared_error', 'friedman_mse', 'absolute_error'],
      'splitter': ['best', 'random'],
      'min_samples_split': [2, 3],
      'max_features': ['auto', 'sqrt', 'log2']
  }
  
  gd_sr = GridSearchCV(estimator = DtReg,
                       param_grid = grid_param,
                       scoring = 'accuracy',
                       cv = 5,
                       n_jobs = -1)
  
  DtReg = gd_sr.fit(X_train, y_train)
  
  plt.figure(figsize = (20, 10))
  plot_tree(DtReg.best_estimator_, filled=True, rounded=True)
  </code></pre>
  <p>Output:</p>
  <pre><code>UserWarning: One or more of the test scores are non-finite: [nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan nan]
  </code></pre>