title: Remove (sub)plot, but keep axis label in matplotlib
body: <p>I want to create a subplot plot in matplotlib with, say, 2 rows and 2 columns, but I only have 3 things to plot and want to keep the <strong>lower left</strong> subplot empty. However, I still want there to be a y-axis label at that position, which is supposed to refer to the whole second row.</p>
  
  <p>This is my code so far: </p>
  
  <pre><code>import matplotlib.pyplot as plt
  
  x = [0, 1]
  y = [2, 3]
  
  ax = plt.subplot2grid((2, 2), (0, 0))
  ax.plot(x, y)
  ax.set_ylabel('first row')
  
  ax = plt.subplot2grid((2, 2), (0, 1))
  ax.plot(x, y)
  
  ax = plt.subplot2grid((2, 2), (1, 0))
  ax.set_ylabel('second row')
  # ax.axis('off')     &lt;---- This would remove the label, too
  
  ax = plt.subplot2grid((2, 2), (1, 1))
  ax.plot(x, y)
  
  plt.show()
  </code></pre>
  
  <p>I have tried using <code>axis('off')</code>, but that removes the label, too. (Same, if I move it one line up, i.e. above <code>ax.set_ylabel('second row')</code>.</p>
  
  <p>So the result so far looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/t3crk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/t3crk.png" alt="lower left plot y u no go away"></a></p>
  
  <p>I want the empty white box (not just its black bounding box or ticks and tick labels) to disappear. Is this possible and if yes, how can I achieve it?</p>