title: Save multiple plots in a single PDF file
body: <h3>plotting module</h3>
  <pre><code>def plotGraph(X,Y):
      fignum = random.randint(0,sys.maxint)
      plt.figure(fignum)
      ### Plotting arrangements ###
      return fignum
  </code></pre>
  <h3>main module</h3>
  <pre><code>import matplotlib.pyplot as plt
  ### tempDLStats, tempDLlabels are the argument
  plot1 = plotGraph(tempDLstats, tempDLlabels)
  plot2 = plotGraph(tempDLstats_1, tempDLlabels_1)
  plot3 = plotGraph(tempDLstats_2, tempDLlabels_2)
  plt.show()
  </code></pre>
  <p>I want to save all the graphs plot1, plot2, plot3 to a single PDF file. Is there any way to achieve it? I can't include the <code>plotGraph</code> function in the main module.</p>
  <p>There's a function named <code>pyplot.savefig</code> but that seems to work only with a single figure. Is there any other way to accomplish it?</p>