title: How to set the alpha value for matplotlib plots globally
body: <p>Using Jupyther Notebooks i often find myself repeadily writing the following to change the alpha value of the plots:</p>
  
  <pre><code>plot(x,y1, alpha=.6)
  plot(x,y2, alpha=.6)
  ...
  </code></pre>
  
  <p>I was hoping to find a matching value in the rcParameters to change to option globally like:</p>
  
  <pre><code>plt.rcParams['lines.alpha'] = 0.6 #not working
  </code></pre>
  
  <p>What is a possible workaround to change the alpha value for all plots?</p>