title: How to set X and Y axis Title in matplotlib.pyplot
body: <p>I have imported:</p>
  
  <p><code>%matplotlib inline
  %config InlineBackend.fugure_format = 'retina'
  import matplotlib.pyplot as plt</code></p>
  
  <p>to show:</p>
  
  <p><code>plt.plot(train_losses, label='Training loss')
  plt.plot(test_losses, label='Test/Validation loss')
  plt.legend(frameon=False)</code></p>
  
  <p><img src="https://i.gyazo.com/59ee1f1bc7f0fca331304086a6d15d35.png" alt="graph"></p>
  
  <p>I have tried <code>plt.xlabel('X axis title')</code> and <code>plt.ylabel('Y axis title</code>) and several other codes but none are working.</p>
  
  <p>I'm just trying to label the x, y axis.</p>