title: Emacs Python-inferior shell not showing prompt after matplotlib show() command
body: <p>So I've been experimenting with numpy and matplotlib and have stumbled across some bug when running python from the emacs inferior shell.</p>
  
  <p>When I send the py file to the shell interpreter I can run commands after the code executed. The command prompt ">>>" appears fine. However, after I invoke a matplotlib show command on a plot the shell just hangs with the command prompt not showing.</p>
  
  <pre><code>&gt;&gt;&gt; plt.plot(x,u_k[1,:]);
  [&lt;matplotlib.lines.Line2D object at 0x0000000004A9A358&gt;]
  &gt;&gt;&gt; plt.show();
  </code></pre>
  
  <p>I am running the traditional C-python implementation. under emacs 23.3 with  Fabian Gallina's Python python.el v. 0.23.1 on Win7. </p>
  
  <p>A similar question has been raised here under the i-python platform: <a href="https://stackoverflow.com/questions/4701607/running-matplotlib-or-enthought-mayavi-mlab-from-a-py-shell-inside-emacs-on-wind">running matplotlib or enthought.mayavi.mlab from a py-shell inside emacs on windows</a></p>
  
  <p><strong>UPDATE: I have duplicated the problem on a fresh instalation of Win 7 x64 with the typical python 2.7.2 binaries available from the python website and with numpy 1.6.1 and matplotlib 1.1.0 on emacs 23.3 and 23.4 for Windows.</strong></p>
  
  <p>There must be a bug somewhere in the emacs shell.</p>