The loop doesn't stopped even when I used the same way to write it

Question

Not working

def player_input():
marker = ''
while 'X' or 'O' not in marker:
      marker = input("Choose between 'X' or 'O': ")
      print ("Please choose between 'X' or 'O'")
     
if marker == 'X':
    return ('X', 'O')
else:
    return ('O', 'X')

Working code

def player_input():
marker = ''
while not (marker == 'X' or marker == 'O'):
    marker = input("Choose between 'X' or 'O': ")
    print ("Please choose between 'X' or 'O'")
     
if marker == 'X':
    return ('X', 'O')
else:
    return ('O', 'X')

I ran both but the loop doesn't stops in first. What is the difference between two?

Does this answer your question? [How to test multiple variables against a value?](https://stackoverflow.com/questions/15112125/how-to-test-multiple-variables-against-a-value) — jasonharper, Oct 19 '20 at 15:49
You're first `while` loop is seen as `while ('X') or ('O' not in number):`. Since `'X'` evaluates to True the loop will run forever. — Matthias, Oct 19 '20 at 15:50
In "while 'X' or ..." the 'X' is already interpreted as true so the whole condition is true regardless of the things following after "or". — Michael Butscher, Oct 19 '20 at 15:50

score 0 · Answer 1 · answered Oct 19 '20 at 16:51

you have indentation error. the if statement is not in the loop. try this code. while loop only run once, because you used else in if statement

def player_input():
    marker = ''
    while not (marker == 'X' or marker == 'O'):
        marker = input("Please choose between 'X' or 'O' >")
        if marker == 'X':
            return ('X', 'O')
        else:
            return ('O', 'X')
print( player_input() )

The loop doesn't stopped even when I used the same way to write it

Not working

Working code

1 Answers1