title: Iterate through directory of files as input to modules
body: <p>I have a module that I want to run on every file in a directory. However, when I iterate over that directory, using each file as an input, the module cannot find the file, as though the variable defined in the loop doesn't actually point to the file. Here is the code I am trying to execute:</p>
  
  <pre><code>import os as os
  
  for file in os.listdir():
      if file.endswith('.fasta'):   
          !python ../iupred2a.py file long
  </code></pre>
  
  <p>Any help is greatly appreciated. Thanks!</p>