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'