学步园

6–2. 字符串标识符.修改例6-1 的idcheck.py 脚本,使之可以检测长度为一的标识符,并且可以识别Python 关键字,对后一个要求,你可以使用keyword 模块(特别是keyword.kelist)来帮你.

import string
from keyword import iskeyword

nums = string.digits
characters = string.letters + '_'

def check(val):
	length = len(val)
	if length == 0:
		print "empty id!"
		return 
	if val[0] not in characters:
		print "error! The first character must me '_' or letters "
		return 
	if iskeyword(value):
		print "error ! %s is a key word !" % value
		return 

	others = val[1:]
	for ch in others:
		if ch not in (nums+characters):
			print "error character :%s" % ch
			return 
	
	print 'valid id!'

if __name__=="__main__":
	while True:
		value = raw_input(">>>\n")
		value = value.strip()
		if value == "quit":
			break
		check(value)