如何调整代码以使其在多个条件下循环返回？

Question

I've looked over tutorials but don't particularly understand the concept.

I'm trying to get my while loop work with multiple conditions/if statements:

while True:
    user_input = raw_input('\n: ').upper()
    if user_input == 'NORMAL':
        user_input = 'Normal'
    if re.match('(ABC|Normal|XY)', user_input):
        check_input = cleaned_dict.get(user_input)
    if not check_input:
        print 'Nope'
    if check_input:
        print 'Yep...'
        etc...
        break

However, I receive an error:

UnboundLocalError: local variable 'check_input' referenced before assignment

...Due to it not looping when the regex pattern does not match.

With only 1 condition it works perfectly.

Thanks in advance.

Answer 1

You have a few options, but the issue is that check_input is not assigned unless there is a regex match. You can either initialize check_input to False outside the loop or add an else clause. I'll show the latter

while True:
    user_input = raw_input('\n: ').upper()
    if user_input == 'NORMAL':
        user_input = 'Normal'
    if re.match('(ABC|Normal|XY)', user_input):
        check_input = cleaned_dict.get(user_input)
    else:
        check_input = False
    if not check_input:
        print 'Nope'
    if check_input:
        print 'Yep...'
    etc...
    break