例一：for循环

for i in range(1,100):        if i==23:            print "great,%s you got your lucky number:" %(i)            break        else:            print 'the number is :',i

 运行：windows下 切换到目录下 Python xunhuan.py

          linux 下      cd到目录下  Python xunhuan.py

例二：阶乘的例子

n=int(input('Enter an integer >=0:'))fact=1for i in range(2,n+1):    fact=fact*i;print(str(n)+'factorial is'+str(fact))

 例三：while循环

total=0s=raw_input('Enter a number(or done):')while s !='done':    num=int(s)    total=total+num    s=raw_input('Enter a number(or done):')print('The sum is '+str(total))

 例四：九九乘法表

for i in range(1,10):    for j in range(1,i+1):        print j, 'x', i, '=', j*i, '\t',    print '\n'print 'done'

 例五、函数定义

import mathdef move(x,y,step,angle=0):    nx=x+step*math.cos(angle)    ny=y+step*math.sin(angle)    return nx,nyx, y = move(100, 100, 60, math.pi / 6)print x,y

 例六、可变参数函数

import mathdef calc(*numbers):    sum = 0    for n in numbers:        sum = sum + n * n    return sumy=calc(1, 2,3,4)print y

 例七：递归函数

def fact(n):    if n==1:        return 1    return n*fact(n-1)    y=fact(5)print y

 例八：尾递归的递归函数

只返回函数本身

def fact(n):    return fact_iter(1, 1, n)def fact_iter(product, count, max):    if count > max:        return product    return fact_iter(product * count, count + 1, max)    y=fact(5)print y

 例九：高阶函数

def add(x, y, f):    return f(x) + f(y)print add(-5, 6, abs)

 把函数作为参数传入，这样的函数称为高阶函数，函数式编程就是指这种高度抽象的编程范式。

例十：字典

color={
   'red':1,'blue':2,'gree':3}print color['gree']color['gree']=0print color

 例十一：一个ping程序

import subprocesscmd="cmd.exe"begin=50end=54while begin

 例十二：os模块

#!/usr/bin/env python# -*- coding:gbk -*-import os  for fileName in os.listdir ( 'd:\\' ):                    print fileName

 例十三：创建目录

#!/usr/bin/env python# -*- coding:gbk -*-#Python对文件系统的操作是通过os模块实现import os  for fileName in os.listdir ( 'd:\\' ):                    print fileNameprint "**************"os.mkdir("d:\\dgx")for fileName in os.listdir ( 'd:\\' ):                    print fileName

 例十四：写入读取的内容到文件

#!/usr/bin/env pythonimport osls=os.linesepwhile True:    fname = raw_input('Enter file name: ')    if os.path.exists(fname):        print "Error:%s already exists "     else:        breakall = []print "\nEnter lines('.'by itself to quit)"while True:    entry=raw_input('>')    if entry =='.':        break    else:        all.append(entry)fobj=open(fname,'w')fobj.write('\n'.join(all))fobj.close()print 'Done'

例十五：读取文件内容

#!/usr/bin/env pythonfname=raw_input('Enter filename:')try:    fobj=open(fname,'r')except IOError,e:    print "*******file open error:",eelse:    for eachLine in fobj:        print eachLine,    fobj.close()

 例十六：第一个main

#-*-coding:utf-8-*-import sysdef Main():      sys.stdout.write("开始程序\n")    str1='i am "python"\n'    str2="i am 'python'\r"    str3="""            i'm "python",                        """    print str1,str2,str3if  __name__ == '__main__':    Main()

 例十七：函数的默认参数与返回值

#-*-coding:utf-8-*-import sysdef arithmetic(x=1,y=1,operator="+"):    result={        "+":x+y,        "-":x-y,        "*":x*y,        "/":x/y             }    return result.get(operator)if __name__=="__main__":    print arithmetic(1, 2)    print arithmetic(1, 2, "/")