title: matplotlib: make plots in functions and then add each to a single subplot figure
body: <p>I haven't been able to find a solution to this.. Say I define some plotting function so that I don't have to copy-paste tons of code every time I make similar plots... </p>
  
  <p>What I'd like to do is use this function to create a few different plots individually and then put them together as subplots into one figure. Is this even possible? I've tried the following but it just returns blanks:</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  
  # function to make boxplots
  def make_boxplots(box_data):
  
      fig, ax = plt.subplots()
  
      box = ax.boxplot(box_data)
  
      #plt.show()
  
      return ax
  
  # make some data:
  data_1 = np.random.normal(0,1,500)
  data_2 = np.random.normal(0,1.1,500)
  
  # plot it
  box1 = make_boxplots(box_data=data_1)
  box2 = make_boxplots(box_data=data_2)
  
  plt.close('all')
  
  fig, ax = plt.subplots(2)
  
  ax[0] = box1
  ax[1] = box2
  
  plt.show()
  </code></pre>