import glob, os 
def all_files(pattern, search_path, pathsep = os.pathsep): 
 for path in search_path.split(pathsep): 
 for match in glob.glob(os.path.join(path, pattern)): 
 yield match 
print(type(all_files('*.s', 'd:\pm\pm'))) 
print(all_files('*.s', 'd:\pm\pm').__next__()) 
for match in all_files('*.s', 'd:\pm\pm'): 
 print(match)