CODEWITHSUNDEEP
pythonwhile-loop
Michael Christensen
Michael Christensen

Reputation: 79

Python infinite loop to check if condition is meet

Sorry if this is very newbie question.

I am trying to make a rock, paper, scissor program.

I want to wait for the user to make eather choice r, p, s.

I am not sure why i cant seem to make it work.

When i run my program, it never gets out of the first while loop whatever i type. I dont understand why is it not going on when i enter eather r, p, or s ?

while p1_choice != 'r' or p1_choice != 's' or p1_choice != 'p':
    p1_choice = input('Player one please make your choice. Rock(r), Scissors(s), Paper(p): ')

while p2_choice != 'r' or p1_choice != 's' or p1_choice != 'p':
    p2_choice = input('Player two please make your choice. Rock(r), Scissors(s), Paper(p): ')
    print()

if p1_choice == 'r' and p2_choice == 'p':
    print('Player two wins')
elif p1_choice == 'r' and p2_choice == 's':
    print('Player one wins')
elif p1_choice == 's' and p2_choice == 'r':
    print('Player two wins')
elif p1_choice == 's' and p2_choice == 'p':
    print('Player one wins')
elif p1_choice == 'p' and p2_choice == 'r':
    print('Player one wins')
elif p1_choice == 'p' and p2_choice == 's':
    print('Player two wins')
else:
    print('The game is a tie')

Upvotes: 1

Views: 463

Answers (4)

Juraj Bublinec
Juraj Bublinec

Reputation: 490

Here is another way, I think the easiest to read:

def getPlayerChoice() -> str:
    choice = '';
    while not (choice == 'r' or choice == 's' or choice == 'p'):
        choice = input('Please make your choice. Rock(r), Scissors(s), Paper(p): ')

p1_choice = getPlayerChoice();
p2_choice = getPlayerChoice();

Upvotes: 1

Federico Baù
Federico Baù

Reputation: 7636

This statement p1_choice != 'r' or p1_choice != 's' or p1_choice != 'p': is always True, hence won't break from the Loop

I strongly suggest you to run the code as follow:

while True:
    p1_choice = input('Player one please make your choice. Rock(r), Scissors(s), Paper(p): ')
    if p1_choice == 'r' or p1_choice == 's' or p1_choice == 'p':
        break
    else:
        continue
        
while True:
    p2_choice = input('Player two please make your choice. Rock(r), Scissors(s), Paper(p): ')
    if p2_choice != 'r' or p1_choice != 's' or p1_choice != 'p':
        continue
    else:
        break

Is more readable and less prone to errors.

Another improvement is, to delegate the check of the User input to a function so:

def check_inputs(user_input):
if user_input == 'r' or user_input == 's' or user_input == 'p':
    print('noe')
    return True
else:
    print('fuckl')
    return False


while True:
    p1_choice = input('Player one please make your choice. Rock(r), Scissors(s), Paper(p): ')
    check = check_inputs(p1_choice)
    if check:
        break
    else:
        continue

This follows the DRY Rule

Upvotes: 0

Amit
Amit

Reputation: 2090

@codewelldev has already nicely pointed out the impossibility to break out of while loop in your code. Since in the OR condition if any condition is True the loop will keep going. You will input one of the following. 'r','s','p'. So because you are negating, there two True(s) and one False at best. It will never finish. May be you want to use 'not in' function.

p1_choice, p2_choice = None, None
while p1_choice not in ('r','s','p'):
    p1_choice = input('Player one please make your choice. Rock(r), Scissors(s), Paper(p): ')

while p2_choice not in ('r','s','p'):
    p2_choice = input('Player two please make your choice. Rock(r), Scissors(s), Paper(p): ')
    print()

if p1_choice == 'r' and p2_choice == 'p':
    print('Player two wins')
elif p1_choice == 'r' and p2_choice == 's':
    print('Player one wins')
elif p1_choice == 's' and p2_choice == 'r':
    print('Player two wins')
elif p1_choice == 's' and p2_choice == 'p':
    print('Player one wins')
elif p1_choice == 'p' and p2_choice == 'r':
    print('Player one wins')
elif p1_choice == 'p' and p2_choice == 's':
    print('Player two wins')
else:
    print('The game is a tie')

Upvotes: 2

codewelldev
codewelldev

Reputation: 246

The first while loop will only stop if p1_choice is equal to 'r', 'p', and 's', simultaneously, which is impossible.

p1_choice != 'r' or p1_choice != 's' or p1_choice != 'p'

evaluates to True

if p1_choice does not equal 'r' or if p1_choice does not equal 'p' or if p1_choice does not equal 's'.

I believe you meant to use and instead of or.

Upvotes: 3

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