Can't finish the loop when asking for valid answers

Question

I have a problem with my code that I can't find the solution as well. I ask for questions that has to be valid but the loops just continues, and let me input.

print('Do you want to go to the store or woods?')

lists = ('woods', 'store')
while True:
    answers = input()    
    if answers == 'store':
        break
        print('Going to the store...')
    elif answers == 'woods':
        break
        print('Going to the woods...')
    while lists not in answers:
        print('That is not a valid answer')

Do you understand that `while lists not in answers:...` loops forever and that you never modify `answer` in that subloop? That means you will never get to the top of the `while True:...` loop. — callyalater, Aug 17 '16 at 16:02
Hi C9 Fox - can you tell us what investigations you have already tried, and what you have found out? For example, have you tried stepping through your code with a debugger? A good Stack Overflow question must demonstrate that you have already done "Search and Research". See the help section's [How To Ask](http://meta.stackexchange.com/help/how-to-ask) guide for more background. — Vince Bowdren, Aug 17 '16 at 17:02

score 2 · Answer 1 · answered Aug 17 '16 at 16:03

You want to check if the user's answer is not in your list of valid answers. What you're doing is the other way around. Try this:

if answers not in lists:
    print('That is not a valid answer')

You'll also want to either break at that point, or print your prompt message again.

score 1 · Answer 2 · answered Aug 17 '16 at 16:03

1

Try this:

print('Do you want to go to the store or woods?')
places = ('woods', 'store')
while True:
    answer = input()
    if answer in places:
        print ("Going to the {0}...".format(answer))
        break
    else:
        print('That is not a valid answer')

answered Aug 17 '16 at 16:03

Fuk Yu

173
1
9

I get not a valid answer regardless of what I write. – C9 Fox Aug 17 '16 at 16:09
I just tested this on my computer and it works. @C9Fox I don't know what you are referring to when you say that you do not get a valid answer... – callyalater Aug 17 '16 at 16:17

score 1 · Accepted Answer · answered Aug 17 '16 at 16:15

First of all, your print statements are unreachable. You can find more information here.

#...
if answers == 'store':
        print('Going to the store...')
        break
    elif answers == 'woods':
        print('Going to the woods...')
        break
#...

Then, your second while statement makes no sense in this way. If you just wanted to print That is not a valid answer in case the input differs from store or woods and give a user another try - then you can just use else, without lists at all:

print('Do you want to go to the store or woods?')

# no lists
while True:
    answers = input()
    if answers == 'store':
        print('Going to the store...')
        break
    elif answers == 'woods':
        print('Going to the woods...')
        break
    else:
        print('That is not a valid answer')

If you instead would like to check, whether the user's input is encountered in lists, then you need to do this in trick inside out:

print('Do you want to go to the store or woods?')

lists = ('woods', 'store')
while True:
    answers = input()
    if answers == 'store':
        print('Going to the store...')
        break
    elif answers == 'woods':
        print('Going to the woods...')
        break
    elif answers not in lists:
        print('That is not a valid answer')
    else:
        # some default case, for example sys.exit() (needs sys to be imported)

@C9Fox I'm happy this helped you! But next time [before creating a question] please consider investigating into your code a bit - for example, read about `break` statements and how do they work, as well as `while` and `continue`. — , Aug 17 '16 at 16:42
I will try but I find it so hard to find information about breaks and loops etc, since they are used in a different way in a different code... — C9 Fox, Aug 17 '16 at 17:30
Well, there are TONS of information about such a common topic. Moreover, all C-like languages implement this. Just find any Python book for beginners and start reading. — , Aug 17 '16 at 17:32
I am very new to coding, started for 3 months ago. I have read automate the boring stuff with python, and done codecademy's python course + treehouse. I am still feeling very fresh it feels like. But maybe i should read another book. — C9 Fox, Aug 17 '16 at 17:50

Can't finish the loop when asking for valid answers

3 Answers3