title: Colab finishes with a ^C
body: <p>I'm running a laplacian pyramid program on Colab that is not vectorized so it takes it's time and when it gets to <code>def vizpyramid()</code> it just exits per below:</p>
  
  <pre><code>100% 1/1 [00:00&lt;00:00, 23.74it/s]
  def computestack
  len grayimgs 2
  gray_imgs[0] shape (500, 333)
  len lapylpyrcolor 3, len lapylpyrcolor[0] 5
  len lapylpyrcolor 3, len lapylpyrcolor[0] 5
  fusedgray shape (500, 333)
  def vizpyramid
  ^C
  </code></pre>
  
  <p>Most of those are from <code>print</code> statements except the <code>100%...</code> and <code>^C</code>.  I did not push control-C so what is happening?  I have checked the function and it works fine on my local machine.  </p>
  
  <p>Edit:  I tried switching to a <code>None</code> no-GPU runtime and now it won't even run with a <code>!python main.py</code> command.</p>