code: def get_file_list(file_dir, regex=''):
      
      file_list = os.listdir(file_dir)
      file_list.sort()
  
      if regex:
          file_list = search_list(file_list, regex)
  
      file_list = [op.join(file_dir, fname) for fname in file_list]
  
      return file_list
docs: Creates a list of files that match the search_regex within file_dir.
      The list of files will have file_dir as path prefix.
  
      Parameters
      ----------
      @param file_dir:
  
      @param search_regex:
  
      Returns:
      --------
      List of paths to files that match the search_regex