title: How to use multiple themes for multiple matplotlib imports
body: <p>I am importing multiple matplotlib as names within my python program and would like to use different styles for different plots.
  However when i change the style for one plot (say : dark_background) it changes the style for all other plots as well.</p>
  
  <p>suggestions shall be appreciated</p>
  
  <p>Current import is something like this : </p>
  
  <pre><code>import matplotlib.pyplot as plt_surfacegt 
  import matplotlib.pyplot as plt_mascon 
  import matplotlib.pyplot as plt_gravmod 
  import matplotlib.pyplot as plt_realtime 
  plt_realtime.style.use('dark_background')
  </code></pre>
  
  <p>it should only change the theme for  plt_realtime to dark however all others are changed to dark as well.! </p>