中奖率

 1 import random
 2 num = 123456
 3 i = 1
 4 while True:
 5     win = random.randrange(100000, 999999)
 6     if num == win:
 7         print('中奖了')
 8         break
 9     i += 1
10 print(i)

运行结果：

中奖了
2438830

猜21点（离21越近的玩家，算赢）

 1 import random, time
 2 
 3 username1 = input('请输入玩家1名字：')
 4 username2 = input('请输入玩家2名字:')
 5 info = {username1: {'count': 0}, username2: {'count': 0}}
 6 while True:
 7     computerNum1 = random.randint(1, 10)
 8     computerNum2 = random.randint(1, 10)
 9     print('输出q退出游戏！')
10     userNum1 = input('输入一个数字(1-10):')
11     userNum2 = input('输入一个数字(1-10):')
12     if userNum1 == 'q' or userNum2 == 'q':
13         print('退出游戏！')
14         break
15 
16     userSum1 = int(userNum1) + computerNum1 + computerNum2
17     userSum2 = int(userNum2) + computerNum1 + computerNum2
18     print('底牌为:', computerNum1, computerNum2)
19     if abs(userSum1 - 21) > abs(userSum2 - 21):
20         print('{}点数为:{}\n{}点数为{},{}获胜！'.format(username1, userSum1, username2, userSum2, username2))
21         info[username2]['count'] += 1
22     else:
23         print('{}点数为:{}\n{}点数为{},{}获胜！'.format(username1, userSum1, username2, userSum2, username1))
24         info[username1]['count'] += 1
25 
26     print('进行下一局，正在洗牌')
27     time.sleep(2)

登录

 1 import random
 2 username = 'admin'
 3 userpw = '123456'
 4 
 5 while True:
 6     yzm = random.randrange(1000, 9999)
 7     loginName = input('请输入用户名:')
 8     loginPw = input('请输入密码:')
 9     loginYzm = int(input('{}请输入验证码:'.format(yzm)))
10     if yzm != loginYzm:
11         print('请输入正确的验证码！')
12         continue
13     if loginName != username:
14         print('当前用户不存在')
15         continue
16     if loginPw == userpw:
17         print('欢迎{}', username)
18         break
19     else:
20         print('密码错误!')

猜数字

num = 10
while True:
    try:
        userNum = eval(input('请输入你要猜的数字:'))
        if userNum == num:
            print('猜对了')
            break
        elif userNum > num:
            print('猜大了')
        else:
            print('猜小了')
    except:
        print('请输入正确的数字')