title: Matplotlib subplots not happy unpacking
body: <p>I'm using a Jupyter notebook and I'd like a grid of subplots that is 6 plots high by 4 plots deep.</p>
  
  <p>Before adding any data or manipulating the plots at all I've tried to run just the following line in isolation:</p>
  
  <pre><code>f, (ax1, ax2) = plt.subplots(6, 4, sharex=True, figsize=(13, 7))
  </code></pre>
  
  <p>It gives this exception:</p>
  
  <pre><code>--------------------------------------------------------------------------- ValueError                                Traceback (most recent call last) &lt;ipython-input-66-4b47dbb065be&gt; in &lt;module&gt;()
       12 # fig, ax = plt.subplots(1, 1, figsize=(13, 7))
       13 
  ---&gt; 14 f, (ax1, ax2) = plt.subplots(6, 4, sharex=True, figsize=(13, 7))
       15 # ax1.plot(x, y)
       16 # ax1.set_title('Sharing Y axis')
  
  ValueError: too many values to unpack
  </code></pre>