title: Matplotlib Deprecation Warning when setting a value in plt.show(). What are the keywords?
body: <p>Going through "Data Science from Scratch" by Joel Grus and trying to code the examples as I go along. Trying to get more than one figure out at a time, I'm pasting what I coded (based on Example 4 in chapter 3). </p>
  
  <p>In order to get the second figure I found I need to set plt.show(0). However when I put in the '0' or 'False' in the bracket I get a warning:</p>
  
  <p>MatplotlibDeprecationWarning: Passing the block parameter of show() positionally is deprecated since Matplotlib 3.1; the parameter will become keyword-only in 3.3.</p>
  
  <pre><code>from matplotlib import pyplot as  plt
  
  mentions = [500, 505]
  years = [2013, 2014]
  
  plt.figure(1)
  plt.bar(years, mentions, 0.8)
  plt.xticks(years)
  plt.ylabel("# of times I heard someone say 'data science'")
  
  # if you don't do this, matplotlib will label the x-axis 0, 1
  # and then add a +2.013e3 off in the corner (bad matplotlib!)
  plt.ticklabel_format(useOffset=False)
  
  # misleading y-axis only shows the part above 500
  
  plt.axis([2012,2015,499,506])
  plt.title("Look at the 'Huge' Increase!")
  plt.show(0)
  
  
  plt.figure(2)
  plt.bar(years, mentions, 0.8)
  plt.xticks(years)
  plt.ylabel("# of times I heard someone say 'data science'")
  
  # if you don't do this, matplotlib will label the x-axis 0, 1
  # and then add a +2.013e3 off in the corner (bad matplotlib!)
  plt.ticklabel_format(useOffset=False)
  plt.axis([2012,2015,0,550])
  plt.title("Not So Huge Anymore")
  plt.show()
  </code></pre>