# 随机4位验证码def yanzhengma():	strvar = ""	for i in range(4):		# 产生大写字母A~Z		bchr = chr(random.randrange(65,91))		# 产生小写字母a~z		schr = chr(random.randrange(97,123))		# 数字0~9		num = str(random.randrange(0,10))		# 把所有随机值得种类塞到列表里		listvar = [bchr,schr,num]		# 随机选取一个		res = random.choice(listvar)		# 拼接字符串		strvar += res	# 返回字符串	return strvarres = yanzhengma()print(res)