On lines 57 through 59, we create our lists that will store the returned dictionaries from our plugin calls. But before we can call our plugins, we need to generate a file listing from the user's input directory argument. We do this on line 65 with the os.walk() function, which we used in previous chapters. A new argument, topdown, is passed to our directory walking loop. This allows us to control the flow of the iteration and step through the directory from the top level down to the furthest level. This is the default behavior, though it can be specified to ensure the anticipated behavior. For each file, we need to join() it with the root to generate the full path to the file:
045 def main(input_dir, ...
