title: I keep on getting the error name 'y_test' is not defined
body: <p>I really need your help! I've written this code:</p>
  <pre><code>from sklearn.model_selection import train_test_split
  from sklearn import metrics
  from sklearn.metrics import accuracy_score
  
  def train_test_rmse(x,y):
      X = df_new[feature_cols]
      y = df_new['TOTAL CONSTRUCTION COST - EXCLUDING TAX']
      X_train, X_test, y_train, y_test = train_test_split(x, y, test_size = 0.2,random_state=123)
      linreg = LinearRegression()
      linreg.fit(X_train, y_train)
      y_test = train_test_split(x, y, test_size = 0.2,random_state=123)
      y_pred = linreg.predict(X_test)
      print(accuracy_score(y_test, y_pred))  
      return np.sqrt(metrics.mean_squared_error(y_test, y_pred)) 
  </code></pre>
  <p>^ The code above runs correctly. But when I try to plot a scatter plot in the cell beneath:</p>
  <pre><code>import matplotlib.pyplot as plt
  plt.scatter(y_test, y_pred)
  plt.xlabel('Actual Y')
  plt.ylabel('Predicted Y')
  plt.show()
  </code></pre>
  <p>I get the error &quot;name 'y_test' is not defined&quot;. Please let me  know how to fix it. Thanks.</p>