old_contents: import sys
  from os import path as osp
  
  
  def main():
      print osp.join(osp.abspath(osp.dirname(__file__)), sys.argv[1])
  
  
new_contents: import sys
  from os import path as osp
  
  
  def main():
      """
      Usage: i19conf FILENAME
  
        Returns the absolute path to FILENAME inside the i19 module.
      """
      assert len(sys.argv) > 1, main.__doc__
  
      modpath = osp.abspath(osp.dirname(__file__))
      fullpath = osp.join(modpath, sys.argv[1])
      if not osp.exists(fullpath):
          sys.exit('"{}" not found in "{}".'.format(sys.argv[1], modpath))
      print fullpath
  
  
  if __name__ == '__main__':
      main()
  
subject: make i19conf spit out an error message when an n00b like me mis-uses it