python - 程序给出了意外的输出——为什么？

Question

我正在编写一个测试算术技能的程序。 它应该生成随机问题，并给出随机操作。 这是我的代码:

import random

score = 0
counter = 0
ops = ['+', '-', '*', '/']

def question():
    num1 = random.randint(0,10)
    num2 = random.randint(1,10) #Starts from 1 to avoid zerodivision error
    operation = random.choice(ops)
    question = float(input(f"What is {num1} {operation} {num2}?: "))
    global answer
    answer = eval(str(num1) + operation + str(num2))
    global counter
    counter = counter + 1


def points():
    while counter < 10:
        question()
        if question == answer:
            print("\nCorrect!\n")
            global score
            score = score + 1
        else:
            print(f"\nWrong! The answer is {answer}\n")


points()

print(f"\nYou got {score} out of {counter}")

但它给出了这个输出:

What is 9 + 3?: 12
Wrong! The answer is 12

如果输入与答案匹配，则应该说正确，并计算分数，最后打印出满分 10 分的分数。

请帮我解决这个问题。

Answer 1

问题出在

if question == answer:

在那一行中，question 是对您之前定义的function question() 的引用。由于 answer 是一些保存问题答案的 int，因此 == 始终为 False。您永远无法真正了解用户输入的内容。

要解决这个问题，请执行以下操作:

def question():
    num1 = random.randint(0,10)
    num2 = random.randint(1,10) #Starts from 1 to avoid zerodivision error
    operation = random.choice(ops)
    user_answer = float(input(f"What is {num1} {operation} {num2}?: "))
    global answer
    answer = eval(str(num1) + operation + str(num2))
    global counter
    counter = counter + 1

    return user_answer

def points():
    while counter < 10:
        user_answer = question()
        if user_answer == answer:
            print("\nCorrect!\n")
            global score
            score = score + 1
        else:
            print(f"\nWrong! The answer is {answer}\n")

我更改了名称，以便更清楚地说明发生了什么。

---

作为附录，我强烈建议不要使用全局变量。它们几乎从不需要并且通常会混淆问题。例如，我认为

def question():
    num1 = random.randint(0,10)
    num2 = random.randint(1,10) #Starts from 1 to avoid zerodivision error
    operation = random.choice(ops)

    user_answer = float(input(f"What is {num1} {operation} {num2}?: "))
    real_answer = eval(str(num1) + operation + str(num2))

    return user_answer, real_answer

def points():
    score = 0
    for questions_asked in range(1, 11):
        user_answer, real_answer = question()
        if user_answer == real_answer:
            print("\nCorrect!\n")
            score += 1
        else:
            print(f"\nWrong! The answer is {answer}\n")

这使得程序流程更容易理解。