def not_all_have_id(files):
 id_reg_exp = re.compile(FILE_PATTERN)
 for file in files:
  ids = id_reg_exp.findall(file)
  if (ids is None):
   return True
 return False

def not_all_have_id ( files ) : id_reg_exp = re . compile ( FILE_PATTERN ) for file in files : ids = id_reg_exp . findall ( file ) if ( ids is None ) : return True return False
return true iff any of the filenames does not conform to the pattern we require for determining the category id .