"UnboundLocalError: local variable 'score' referenced before assignment"

Question

每次我运行我的程序，在回答完第一个问题后，我都会收到这个消息。我不明白为什么会一直发生这种情况，因为我已经在一切之前创建了分数变量，我不明白为什么会有问题。我该如何解决这个问题？这是我的代码。

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

当你在函数定义中引用一个变量时（方法除外），python会引用本地的可变量。你可以编辑 score 作为一个全局变量，用 global 关键字。

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 2

变量的范围是 score 不在 quiz1. 因此，我会把它传进去，并以合适的方式返回。

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 3

使 score 全局性的，添加 global score 在函数的第一行。

Answer 4

这可能有助于

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()