用Python实现一个简单的算术游戏:

#!/usr/bin/env python

from operator import add, sub
from random import randint, choice

ops = {'+': add, '-':sub}
#定义一个字典
MAXTRIES = 2

def doprob():
op = choice('+-')
#用choice从'+-'中随意选择操作符
  nums = [randint(1,10) for i in range(2)]
#用randint(1,10)随机生成一个1到10的数,随机两次使用range(2)
 nums.sort(reverse=True)
#按升序排序
  ans = ops[op](*nums)
#利用函数
 pr = '%d %s %d = ' % (nums[0], op, nums[1])
oops = 0
#oops用来计算failure测试,当三次时自动给出答案
while True:
try:
if int(raw_input(pr)) == ans:
print 'correct'
break
if oops == MAXTRIES:
print 'answer\n %s%d' % (pr, ans)
break
else:
print 'incorrect... try again'
oops += 1
except (KeyboardInterrupt, EOFError, ValueError):
print 'invalid ipnut... try again'
def main():
while True:
doprob()
try:
opt = raw_input('Again [y]').lower()
if opt and opt[0] == 'n':
break
except (KeyboardInterrupt, EOFError):
break

if __name__ == '__main__':
main()