python 基础 2.4 while 循环

#/usr/bin/python 
#coding=utf-8 
#@Time   :2017/10/18 15:31 
#@Auther :liuzhenchuan 
#@File   :while 循环.py

示例1：

 n = 0
 while True:
     print 'hello world'
     if n == 10:
         break
     n +=1

打印如下：

 hello world
 hello world
 hello world
 hello world
 hello world
 hello world
 hello world
 hello world
 hello world
 hello world
 hello world

示例2：

 n = 0
 while True:
     if n==10:
         break
     print n ,'hello'
     n +=1

打印如下：

 0 hello
 1 hello
 2 hello
 3 hello
 4 hello
 5 hello
 6 hello
 7 hello
 8 hello
 9 hello

示例3：

#条件为假的时候，也是退出循环.输入空字符的时候也退出循环

 rinput = ''
 while rinput !='q':
     rinput = raw_input('please input something,q is quite: ')
     print 'hello'
     if rinput == '':
         break

示例4：

#应用逻辑非判断，退出while循环。while条件为假时，退出while循环

 rinput = ''
 while rinput !='q':
     rinput = raw_input('please input something,q is quite: ')
     print 'hello'
     if not rinput :
         break

示例5：

# while...else...:正常结束while循环时会打印else后面的语句.与for...else...循环体一样

 rinput = ''
 while rinput !='q':
     rinput = raw_input('please input something,q is quite: ')
     print 'hello'
     if not rinput :
         break
 else:
     print 'hello world'

示例6：

#while 循环嵌套if循环体，支持contine

 rinput = ''
 while rinput !='q':
     rinput = raw_input('please input something,q is quite: ')
     print 'hello'
     if not rinput :
         break
     elif rinput == 'quite':
         continue
         print 'continue'
 else:
     print 'hello world'