title: Formatting y-axis matplotlib with thousands separator and font size
body: <p>The code below works.</p>
  
  <p>names = years 1960 - 2016</p>
  
  <p>values = GDP of the US for each year</p>
  
  <p>The code produces two charts, but the y-axis label runs from 5000 to 175000.  I want to 
  1) format the label with a "," for a thousands separator, so as an example, 5,000 or 17,500, and,</p>
  
  <p>2) I want to increase the font size of the labels - so increase the font of, for example, 5000.</p>
  
  <p>Not finding a workable/understandable example on line.  Help appreciated.</p>
  
  <pre><code>%matplotlib inline
  import matplotlib.pyplot as plt
  plt.style.use('seaborn-white')
  import numpy as np
  from numpy import array
  
  # Plot GDP/Year
  
  names =  usa.loc[: , "Year"]
  values = usa.loc[: , "GDP Billions"]
  
  plt.figure(1, figsize=(15, 6))
  plt.suptitle('GDP Growth', fontsize=20)
  
  plt.subplot(121)
  plt.plot(names, values)
  plt.xticks(np.arange(0, 57, step=5.0))
  plt.ylabel('GDP', fontsize=16)
  plt.title('United States',fontsize=16)
  
  plt.subplot(122)
  plt.plot(names, values)
  plt.xticks(np.arange(0, 57, step=5.0))
  plt.xlabel('Year', fontsize=16)
  plt.title('United States',fontsize=16)
  
  #plt.ticklabel_format(axis='y', style='sci', scilimits=(0, 4))
  #print(plt.xticks())
  
  
  plt.show()
  </code></pre>