Python：如何使python计算总和以确保输入正确？

Question

我想让python提出10个问题，并且用户必须输入有效的答案。 但是我也想让python通过使用下面的代码来说这是否正确，但这是行不通的，只会进入下一个问题。 有人可以告诉我为什么吗？ 还是我需要改变？ 另外，如何使用我拥有的变量和while循环使这个问题10变得特别？

import time
import random
question = 0
score = 0
name = input("What is your full name?")
print ("Hello " + name, "welcome to The Arithmetic Quiz")
time.sleep(2)
operand1 = list(range(2, 12))
operators = ["+"]
operand2 = list(range(2, 12))

while question < 10:
    user_answer=int(input(str(random.choice(operand1)) + random.choice(operators) + str(random.choice(operand2))))
    if operators=='+':
        expected_answer==operand1 + operand2
        if user_answer==expected_answer:
            print('This is correct!')
            score = score + 1
            question = question + 1
            time.sleep(2)
        else:
            print('This is incorrect!')
            question = question + 1
            time.sleep(2)

Answer 1

while语句中的所有比较都是针对list而不是针对随机选择的元素进行的。

您可能想要执行以下操作：

operands1 = list(range(2, 12))
operators = ["+"]
operands2 = list(range(2, 12))

while question < 10:
    operand1 = random.choice(operands1)
    operand2 = random.choice(operands2)
    operator = random.choice(operators)
    user_answer = int(input('{} {} {} '.format(operand1, operator, operand2)))
    if operator == '+':
        expected_answer = operand1 + operand2
        if user_answer == expected_answer:
            print('This is correct!')
            score = score + 1
            question = question + 1
            time.sleep(2)
        else:
            print('This is incorrect!')
            question = question + 1
            time.sleep(2)

还有许多其他方法可以改善代码的结构，这可能会使代码看起来像这样：

import operator as ops
import time
import random

NUM_QUESTIONS = 10
OPERANDS = list(range(2, 12))
OPERATORS = {'+': ops.add, '-': ops.sub, '*': ops.mul}

def getInteger(prompt, errormsg='Please input an integer'):
    while True:
        try:
            return int(input(prompt))
        except ValueError:
            print(errormsg)

def main():
    question = score = 0

    name = input('What is your full name? ')
    print('Hello {}, welcome to The Arithmetic Quiz'.format(name))
    time.sleep(2)

    for _ in range(NUM_QUESTIONS):
        operand1 = random.choice(OPERANDS)
        operand2 = random.choice(OPERANDS)
        operator = random.choice(list(OPERATORS))

        user_answer = getInteger('{} {} {} '.format(operand1, operator, operand2))
        expected_answer = OPERATORS[operator](operand1, operand2)
        if user_answer == expected_answer:
            print('This is correct!')
            score += 1
        else:
            print('This is incorrect!')
        time.sleep(2)

if __name__ == '__main__':
    main()

这使用专用的getInteger函数来处理无效输入，使用字典和作为第一类对象的函数来选择要使用的“实际”运算符函数，使用+= ，使用range和for ，而不是while循环，使用合理的常量...可能的改进清单很大。

Answer 2

这是代码的错误

import time
import random
question = 0
score = 0
name = input("What is your full name?")
print ("Hello " + name, "welcome to The Arithmetic Quiz")
time.sleep(2)
operand1 = list(range(2, 12))
#Choice works fine with ranges 
#No need to transform it with a list
operators = ["+"]
operand2 = list(range(2, 12))
#Using the for loop is more Pythonic
while question < 10: 
    user_answer=int(input(str(random.choice(operand1)) + random.choice(operators) + str(random.choice(operand2))))
    if operators=='+': ##Over here you were comparing a list to a str
        expected_answer==operand1 + operand2 ##This is a boolean operator not an int value
        if user_answer==expected_answer:
            print('This is correct!')
            score = score + 1
            question = question + 1
            time.sleep(2)
        else:
            print('This is incorrect!')
            question = question + 1
            time.sleep(2)

正如Kupiakos所说，有很多方法可以优化代码，而他已经介绍了大多数方法。 我将指出解决上述问题的方法。

import time
from random import choice, randint
question, score = 0, 0

name = input("What is your full name?\n>>> ")
print ("Hello {} welcome to The Arithmetic Quiz\n".format(name))
time.sleep(2)

for _ in range(10):
    operand1, operand2 = [randint(2, 12) for _ in range(2)]
    op = choice(['+'])##You have to store the value so that you can compare it later
    user_answer=int(input('{0}{2}{1}\n>>> '.format(operand1, operand2, op) ))
    if op == '+':
        expected_answer = operand1 + operand2
        if user_answer == expected_answer:
            print('This is correct!')
            score += 1
            question += 1
            time.sleep(2)
        else:
            print('This is incorrect!')
            question = question + 1
            time.sleep(2)
print('Your score is: {} points'.format(score))

祝你学生好运。

Answer 3

以下是您的问题的解决方案：

import time
import random

question = 0
score = 0
name = input("What is your full name?")
print ("Hello " + name, "welcome to The Arithmetic Quiz")
time.sleep(2)
operand1 = list(range(2, 12))
operand2 = list(range(2, 12))

while question < 10:
    num1 = random.choice(operand1)
    num2 = random.choice(operand2)
    print(str(num1) + "+" + str(num2))
    user_answer = int(input())
    expected_answer = int(num1) + int(num2)
    if user_answer == expected_answer:
        print('This is correct!!')
        score = score + 1
        question = question + 1
    else:
        print('This is incorrect!!')
        question = question + 1

print("\nYour score is " + str(score))

这里不需要操作数变量，而是可以将+运算符本身作为字符串传递。 另外，由于将操作数1和操作数2作为列表而不是整数进行传递，expected_answer变量也无法解析求和。