title: Using python 2 or 3, matplotlib and tkinter causes an extra empty window to open on calling plt.show()
body: <p>I am making an interactive data analysis tool that I am having trouble with (in <code>python 2.7</code>, <code>3.4</code> and <code>3.5</code>). The full program makes graphs that the user has to interact with and then close. It also requires the user to input files via a filechooser. </p>
  
  <p>The issue is whenever I use <code>plt.show()</code> an additional small window opens (which I don't want) along with the graph. The small window then has to be closed too, to continue the program. Not that big a deal, but there are many graphs to interact with, so it is a bit off a pain always closing two windows.</p>
  
  <p>If the <code>Tkinter.Tk().withraw()</code> is uncommented only the plot opens, but now the program just hangs upon closing the graph and I have to kill the process. </p>
  
  <p>Any ideas for how I might get around this problem?</p>
  
  <p>Thanks in advance. Example code:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  try:
      import Tkinter
  except (ImportError):
      import tkinter as Tkinter
  try:
      from tkFileDialog import askopenfilename
  except (ImportError):
      from tkinter.filedialog import askopenfilename
  
  # Tkinter.Tk().withdraw()
  
  print(askopenfilename())
  
  
  x = np.arange(0,5,0.1)
  y = np.sin(x)
  
  plt.plot(x,y)
  plt.show()
  </code></pre>