重复使用与上一个问题相同的值。哪个函数包含错误？

Question

如果用户选择再次玩游戏，并选择他们要使用的操作，则程序仍将使用上一个游戏中的操作符号。请参见下面的代码。

import random

print "Welcome!"

def get_choice():
    print "What are we practicing? \n1. Addition (+) \n2. Subtraction (-) \n3. Multiplication (*) \n4. Division (/)"

    option = raw_input('> ')

    while option != '+' and option != '-' and option != '*' and option != '/':
        print "You typed %r which is not valid. Please enter \'+, -, *,or /\'" %(option)
        option = raw_input('>')
    return option

operation = get_choice()

def ask_question (operation):
    numbers = []
    for y in range(0,2):
        x = random.randint(1,100)
        numbers.append(x)
    num1 = numbers[0]
    num2 = numbers[1]
    print num1, operation, num2
    response = int(raw_input('>'))
    return num1, num2, response

num1, num2, response = ask_question(operation)

def check_response(response):
    if operation == '+':
        answer = num1 + num2
    elif operation == '-':
        answer = num1 - num2
    elif operation == '*':
        answer = num1 * num2
    else:
        answer = num1 / num2

    i = 0
    if response == answer:
        print "Correct!"
    elif response != answer:
        while i < 2:
            print "Wrong! Try again: \n%r + %r" %(num1, num2)
            i += 1
            response = raw_input()
            if response != answer and i >= 2:
                print "Sorry. You run out of chances."

check_response(response)

def repeat():
    while True:
        print "Do you want to play again?"
        again = raw_input('>')
        if again == 'y' or again == 'Y':
            get_choice()
            ask_question(operation)
            check_response(response)
        else:
            break   
repeat()

请参见下面的示例输出。

欢迎光临！ 我们在练习什么？ 1.加法（+） 2.减法（-） 3.乘法（*） 4.除法（/）

  

+   78 + 28   106   正确！   你想再玩一次吗？   ÿ   我们在练习什么？   1.加法（+）   2.减法（-）   3.乘法（*）

     

4。部门（/）

     

62 + 85