“UnboundLocalError: local variable 'score' referenced before assignment”

Question

Every time I run my program I get that message after answering the first question. I don't understand why this keeps happening because I have created the score variable before everything, I don't see why there is an issue. How do I solve this? This is my code:

score = 0

name = input("Before we start, what would you like me to call you? : ")

def greeting():
    print ("Welcome to your Math review quiz,",name)
    print("You will have to answer 5 questions")

def quiz1():
    q1 = int (input("5 + 5 : "))
    if q1 == 10:
        print("Correct")
        score = score + 1
    else :
        print ("Incorrect")
    q2 = int (input ("5 + 10 : "))
    if q2 == 15 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")
    q3 = int (input ("50 + 10 : "))
    if q3 == 60 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

    q4 = int (input ("50 + 50 : "))
    if q4 == 100 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

greeting()
quiz1()

Answer 1

The scope of the variable score is not in quiz1 . Therefore, I would pass it in, and return it as fit:

score = 0

name = input("Before we start, what would you like me to call you? : ")

def greeting():
    print ("Welcome to your Math review quiz,",name)
    print("You will have to answer 5 questions")

def quiz1(score):
    q1 = int (input("5 + 5 : "))
    if q1 == 10:
        print("Correct")
        score = score + 1
    else :
        print ("Incorrect")
    q2 = int (input ("5 + 10 : "))
    if q2 == 15 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")
    q3 = int (input ("50 + 10 : "))
    if q3 == 60 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

    q4 = int (input ("50 + 50 : "))
    if q4 == 100 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")
    return score

greeting()
score = quiz1(score)

Answer 2

When you refer to a variable in a function definition (other than methods) python refers to the local veriable. You can edit score as a global variable with the global keyword.

score = 0

name = input("Before we start, what would you like me to call you? : ")

def greeting():
    print ("Welcome to your Math review quiz,",name)
    print("You will have to answer 5 questions")

def quiz1():
    global score # add this line #
    q1 = int (input("5 + 5 : "))
    if q1 == 10:
        print("Correct")
        score = score + 1
    else :
        print ("Incorrect")
    q2 = int (input ("5 + 10 : "))
    if q2 == 15 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")
    q3 = int (input ("50 + 10 : "))
    if q3 == 60 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

    q4 = int (input ("50 + 50 : "))
    if q4 == 100 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

greeting()
quiz1()

Answer 3

make score global, add global score in the first line in the function.

Answer 4

This might help

name = input("Before we start, what would you like me to call you? : ")

def greeting():
    print ("Welcome to your Math review quiz,",name)
    print("You will have to answer 5 questions")

def quiz1():
    score = 0
    q1 = int (input("5 + 5 : "))
    if q1 == 10:
        print("Correct")
        score = score + 1
    else :
        print ("Incorrect")
    q2 = int (input ("5 + 10 : "))
    if q2 == 15 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")
    q3 = int (input ("50 + 10 : "))
    if q3 == 60 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

    q4 = int (input ("50 + 50 : "))
    if q4 == 100 :
        print("Correct")
        score = score + 1
    else :
        print("Incorrect")

greeting()
quiz1()