#!/usr/bin/pythonstack = []def pushit():stack.append(raw_input('enter new string: ').strip())def popit():if len(stack)==0:print 'cannot pop from an empty stack'else:

#!/usr/bin/python#coding=utf-8import urllibprint '将赶集首页的html抓取到本地，保存在g.txt文件中，同时显示下载的进度。'def fun(blocknum , blocksize ,totalsize):percent = 100.0*blocknum*blocksize/totalsizeif percent

#!/usr/bin/pythondb = {}def newuser():prompt='login desired: 'while True:name = raw_input(prompt)if db.has_key(name):prompt='name take, try another: '

#! /usr/bin/python#coding=utf-8import osusrdir = '/usr/local'os.chdir(usrdir)cwd = os.getcwd()print'***当前目录为: ',cwdprint '创建文件'os.mkdir('example')os.chdir('example')cwd=os.getcwd()print '