title: Previously instantaneous function doesn't end at second call
body: <p>I have a weird behavior that I cannot seem to identify. I could try to summarize it up like this:</p>
  
  <pre><code>    def custom_function(input_list):
          output_sum = 0
          for number in input_list:
              output_sum += number
          return output_sum
  
      tmp_list = [0, 12, 129]
      tmp_list2 = [19, 0, 18]
  
      print tmp_list
      print custom_function(tmp_list)
  
      print tmp_list2
      print custom_function(tmp_list)
  </code></pre>
  
  <p>In this case, consider the <code>custom_function</code> to be way more complicated. I would just like to know the kind of stuff it might be coming from. If you need more insights I would love to describe <code>custom_function</code> in more details.</p>
  
  <p>The output will look like this, and the script will keep running without giving any answer, while the first iteration of custom_function was instantaneous.</p>
  
  <pre><code>    [0, 12, 129]
      141
      [19, 0, 18]
  </code></pre>
  
  <p>Do you guys have any idea of where this kind of problem might be coming from? When I kill the script the Trace Back always indicate me a different call, as if the last function was just taking 2 days to execute.</p>