/* while 是在有条件控制的情况下 进行的循环 */[root@localhost test1]# vim 13.py//ADD#!/usr/bin/pythonn = 0while True:    if n == 10:        break    print n, ‘hello‘    n += 1[root@localhost test1]# python 13.py0 hello1 hello2 hello3 hello4 hello5 hello6 hello7 hello8 hello9 hello

[root@localhost test1]# vim 14.py//ADD#!/usr/bin/pythonwhile True:    print ‘hello‘    input = raw_input("Please input something.q for quit: ")    if input == "q":        break[root@localhost test1]# python 14.pyhelloPlease input something.q for quit: ehelloPlease input something.q for quit: rhelloPlease input something.q for quit: thelloPlease input something.q for quit: fhelloPlease input something.q for quit: q

[root@localhost test1]# vim 15.py//add#!/usr/bin/pythonx = ‘‘while x != ‘q‘:    print ‘hello‘    x = raw_input("Please input something, q for quit: ")/* 首先，要给x定义一个初始值，    然后再继续执行。 这里没有定义输入q后会有什么结果，    但是执行后，输入q则自动退出*/[root@localhost test1]# python 15.pyhelloPlease input something, q for quit: shelloPlease input something, q for quit: shelloPlease input something, q for quit: dhelloPlease input something, q for quit: fhelloPlease input something, q for quit: ghelloPlease input something, q for quit: q

/* 先创建一个文件 */[root@localhost tmp]# cat 1.txt1111//先用一个变量定义，这个变量对应什么文件In [1]: ll = open(‘/tmp/1.txt‘)In [2]: llOut[2]: <open file ‘/tmp/1.txt‘, mode ‘r‘ at 0x99d81d8>//将这个文件或变量打开，并赋予w权限In [4]: ll = open(‘/tmp/1.txt‘, ‘w‘)//写变量。括号里为写的内容，此处写的内容会覆盖原来的内容In [5]: ll.write("aa")[root@localhost tmp]# cat 1.txtaa[root@localhost tmp]#/* 有时，需要需要将变量关掉才可以执行看到改变 *//* 再一次打开python的界面需要重新定义变量。*/In [2]: ll = open(‘/tmp/1.txt‘)In [3]: ll.read()　　　　//从最开始读Out[3]: ‘aa‘In [4]: ll.read()　　　　//当第二次读取时，指针已经读完了前面的内容，就只剩空了Out[4]: ‘‘

/* 读取的具体内容 *///1. 输入需要读取的 前几个字符[root@localhost tmp]# cat 1.txtabcsjdh[root@localhost tmp]#In [1]: ll = open(‘/tmp/1.txt‘ , ‘r‘)In [2]: llOut[2]: <open file ‘/tmp/1.txt‘, mode ‘r‘ at 0x9392180>In [3]: ll.read(2)Out[3]: ‘ab‘// 2.读取一行In [1]: ll = open(‘/tmp/1.txt‘)In [2]: ll.readline()Out[2]: ‘abc\n‘// 3.读取多行（有多少行读多少行），并且返回一个list// 4. next() 可对一个文件一行一行的读取In [5]: ll = open(‘/tmp/1.txt‘)In [6]: ll.readlines()Out[6]: [‘abc\n‘, ‘sjdh‘]In [1]: ll = open(‘/tmp/1.txt‘)In [2]: ll.next()Out[2]: ‘abc\n‘In [3]: ll.next()Out[3]: ‘sjdh‘In [4]: ll.next()---------------------------------------------------------------------------StopIteration                             Traceback (most recent call last)<ipython-input-4-e9a4e3e4293f> in <module>()----> 1 ll.next()StopIteration:

/* python脚本，对文件进行遍历 */[root@localhost test1]# vim 16.py//ADD#!/usr/bin/pythonll = open(‘/tmp/1.txt‘)for line in ll.readlines():    print line,[root@localhost test1]# python 16.pyabcsjdh