from random import randint
from random import choice
def exam():
'用于出题，用户作答'
# 随机生成两个整数
nums = [randint(1, 100) for i in range(2)]
nums.sort(reverse=True) # 降序排列
# nums.reverse()
# 随机选择加减法
op = choice('+-')
# 计算出标准答案
if op == '+':
result = nums[0] + nums[1]
else:
result = nums[0] - nums[1]
# 用户作答，判断正误
prompt = f'{nums[0]} {op} {nums[1]} = '
n = 0
while n <3 :
try:
answer = int(input(prompt))
except ValueError:
print('无效输入，重输')
continue
if answer == result:
print('你真棒!!!')
break
else:
print('不对哟!!!')
n+= 1
else:
print(f'corect answer is :\n{prompt}{result}')
def main():
'主程序代码逻辑'
while 1:
exam()
try:
yn = input('Continue(Y/n)? ').strip()[0] # 取出用户输入的第一个非空字符
except (KeyboardInterrupt,EOFError):
print('\nBye-bye')
break
except IndexError:
continue
if yn in 'nN':
print('\nBye-bye')
break
if __name__ == '__main__':
main()
