Why does python return "NameError: name 'correct' is not defined when it has been defined? [duplicate]

Question

Essentially I am making a quiz, and python returns an error saying the variable shown below is undefined when it has been defined.

def guesscheck(guess, answer):
    correct = "null"
    print(lives * '\u2665')
    if guess.upper() == answer:
        print("Marvelous! That is correct!")
        correct = True
        return correct 
    if guess.upper() != answer:
        print("That is incorrect.")
        correct = False
        return correct

lives = 3
guess = input("ok: ")
guesscheck(guess, "OK")
if correct == False:
    lives = lives - 1
    print(lives * '\u2665')

As you can see, I call the function which should define the variable 'correct' as True or False and return it to the rest of the program, but for some reason it is showing as undefined. Please help me!

hard to tell since you haven't formatted the code, but seems that the issue is that correct is in local scope to the function, try adding global correct at the top of function definition — Matiiss
– Matiiss, Commented Aug 7, 2021 at 15:21
It's only defined within the body of the guesscheck function. See docs.python.org/3/tutorial/… — snakecharmerb
– snakecharmerb, Commented Aug 7, 2021 at 15:21
@JustANoobProgrammer, Yes the return <variable> statement does return something, but neither the name of a variable, nor a value, but a reference. And in order to use the reference you have to assign it to a variable of your own as the many answers suggest. — quamrana
– quamrana, Commented Aug 7, 2021 at 15:34

enzo · Accepted Answer · 2021-08-07 15:26:58Z

1

You should return the correct variable from your function and then access it when calling guesscheck:

def guesscheck(guess, answer):
    # This variable declaration is not necessary
    # correct = "null"
    #
    # Instead, you can assign it to the answer check
    correct = guess.upper() == answer

    print(lives * '\u2665')

    if correct:
        print("Marvelous! That is correct!")

    # You can use an else-clause here
    else:
        print("That is incorrect.")

    return correct

Then access it like this:

lives = 3
guess = input("ok: ")
correct = guesscheck(guess, "OK")
# No need for `correct == False`
if not correct:
    lives = lives - 1
    print(lives * '\u2665')

answered Aug 7, 2021 at 15:26

enzo

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2 Comments

JustANoobProgrammer Over a year ago

Is "if not correct:" essentially a rewritten version of "correct == False:"?

enzo Over a year ago

Actually, not correct also checks for additional things, such as empty strings and empty lists, while correct == False strictly checks for the boolean value False, but since guesscheck only returns a boolean, in your case they are equivalent.

balderman · Accepted Answer · 2021-08-07 15:25:09Z

1

Try the below (note how correct is used in the main loop)

def guesscheck(guess, answer):
    correct = "null"
    print(lives * '\u2665')
    if guess.upper() == answer:
        print("Marvelous! That is correct!")
        correct = True
        return correct 
    if guess.upper() != answer:
        print("That is incorrect.")
        correct = False
        return correct

lives = 3
while lives:
    guess = input("ok: ")
    correct = guesscheck(guess, "OK")
    if not correct:
        lives = lives - 1
        print(lives * '\u2665')

answered Aug 7, 2021 at 15:25

balderman

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2 Comments

JustANoobProgrammer Over a year ago

Thank you, however, the code keeps running forever, and I need it to stop at some point so that I can put more than one question into the quiz code.

balderman Over a year ago

@JustANoobProgrammer I can see no reason for making correct global - isnt it?

quamrana · Accepted Answer · 2021-08-07 15:30:05Z

1

You do not define correct outside of the function, it is only available on the local scope.

Assigning on the outside scope should fix your problem.

correct = guesscheck(guess, "OK")

edited Aug 7, 2021 at 15:30

quamrana

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answered Aug 7, 2021 at 15:25

Işık Kaplan

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