字符串索引超出python范围？

Question

我正在用python创建一个安全登录程序，并且不断收到此错误消息： IndexError: string index out of range.

错误是针对line character=password[c] 。 我正在检查用户输入的密码是否有数字。 如果没有数字，则密码无效。 我该如何解决？

while c<numbercharacters:
    character=password[c] 
    c=c+1
    while character!="1" and character!="2" and character!="3" and character!="4" and character!="5" and character!="6" and character!="7" and character!="8" and character!="9" and character!=0: #checking if password has a number
        print "This password is not valid, it does not contain a number. Please create another." 
        password= raw_input ()
        numbercharacters=len(password) 
        character=password[c] 

c是计数器的变量。

Answer 1

当您获得新的密码输入时（由于无效），您无需将计数器c重置为零即可再次从头开始检查过程。

# After this block
password= raw_input ()
numbercharacters=len(password) 
# Reset your counter to zero
c = 0
character=password[c]

您也可以简单地使用以下任一方法为字符检查数字

while not character.isdigit():
# or 
while character not in '0123456789':

Answer 2

如果要检查是否有电话号码，您可以做

password= raw_input ()
if not any(character.isdigit() for character in password):
    print "This password is not valid, it does not contain a number. Please create another." 

如果您想重新询问密码直到输入密码

 password= raw_input ()
 if not any(character.isdigit() for character in password):
    while not any(character.isdigit() for character in password):
        print "This password is not valid, it does not contain a number. Please create another." 
        password= raw_input ()