while循环

while循环是死循环，没有触发条件退出的话会一直运行

没有触发条件

1 count = 0
2 while True:
3     print("count.",count)
4     count +=1

循环100次退出

1 count = 0
2 while True:
3     print("count",count)
4     count +=1
5     if count == 100:
6        break

还是猜年龄游戏，让用户不断的猜年龄，但只给最多3次机会，再猜不对就退出程序

 1 #! /usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 
 4 my_age = 28
 5 count = 0
 6 
 7 while count < 3:
 8     guess_age = int(input("input your guess age:"))
 9     if guess_age == my_age:
10         print("Congratulations, you got it!")
11         break
12     elif guess_age > my_age:
13         print("think smaller...")
14     else:
15         print("think bigger!")
16     count += 1
17 else:
18     print("you have tried too many times...")

继续猜年龄游戏，让用户不断的猜年龄，猜3次后，问是否继续？输入n就退出程序，输入其它就继续

 1 #! /usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 # Author: Ruan
 4 
 5 my_age = 28
 6 
 7 count = 0
 8 
 9 while count < 3:
10     guess_age = int(input("input your guess age:"))
11     if guess_age == my_age:
12         print("Congratulations, you got is!")
13         break
14     elif guess_age > my_age:
15         print("think smaller...")
16     else:
17         print("think bigger!")
18     count += 1
19 
20     if count == 3:
21         continue_confirm = input("do you want to keep guessing...?")
22         if continue_confirm != 'n':
23             count = 0

PS:while---else---是python独有的语法，其它语言中不能使用此方法。

while循环

推荐阅读