Why does not the variable check in the while loop, change the boolean from True to False?

def word_valid():
    words = input("Your word: ").upper()

    global check
    check = False
    return words

def main():
    check = True
    while check is True:
        words = word_valid()
    print(words) #Won't print out

if __name__ == '__main__':
    main()

CodePudding user response：

global refers to the global scope, but the check in main is local to main's scope. That is, the check you're mutating in word_valid is a different check to the one in main

Without thinking too much about how to do this nicely, you could return check

def word_valid():
    words = input("Your word: ").upper()

    check = False
    return words, check

def main():
    check = True
    while check is True:
        words, check = word_valid()
    print(words) #Won't print out

if __name__ == '__main__':
    main()