71-使用函数编写数字游戏

随机从1到100随机取2个数值进行随机的相加减，输错3次给答案。

from random import randint,choice

def add(x,y):  # 定义加函数
    return x + y

def sub(x,y):  # 定义减函数
    return x - y

def exam():
    cmds = {'+':add,'-':sub}  # 加减函数的字典
    nums = [randint(1,100) for i in range(2)]  # 随机取2个数值放在列表里
    nums.sort(reverse=True)  # 列表降序排列
    op = choice('+-')  # 随机选择加或者减
    result = cmds[op](*nums)  # 随机值相加减的结果
    prompt = "%s %s %s = " %(nums[0],op,nums[1])
    tries = 0

    while tries < 3:
        try:
            answer = int(input(prompt))  # 用户输入答案
        except:
            continue

        if answer == result:
            print("You are right!")
            break

        else:
            print("You are wrong!")
            tries += 1
    else:  # 猜对了直接跳出循环，3次全猜错了才执行，给出答案。
        print("%s %s" %((prompt,result)))

if __name__ == '__main__':
    while True:
        exam()
        try:
            yn = input("Continue(y/n)? ").strip()[0]
            print(yn)
        except IndexError:
            continue
        except (KeyboardInterrupt,EOFError):
            print()
            yn = 'n'
        if yn in 'nN':
            break

结果输出：

62 - 29 = 20
You are wrong!
62 - 29 = 30
You are wrong!
62 - 29 = 50
You are wrong!
62 - 29 =  33
Continue(y/n)? y
y
25 + 16 = 41
You are right!
Continue(y/n)? n
n