“UnboundLocalError：赋值前引用了局部变量‘score’”

Question

每次我运行我的程序时，我都会在回答第一个问题后收到该消息。 我不明白为什么会一直发生这种情况，因为我在一切之前都创建了 score 变量，我不明白为什么会出现问题。 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

变量score的 scope 不在quiz1中。 因此，我会将其传入，并根据需要返回：

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 2

当您在 function 定义（方法除外）中引用变量时，python 指的是本地可验证的。 您可以使用global关键字将score编辑为全局变量。

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，在 function 的第一行添加global score 。

Answer 4

这可能会有所帮助

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()