Python 常用代码片段，,一些比较常用的pytho

Python 常用代码片段，,一些比较常用的pytho

一些比较常用的python代码片段

1、生成随机数

import random    #这个是注释，引入模块rnd = random.randint(1,500)#生成1-500之间的随机数

2、python读文件

f = open("c:\\1.txt","r")lines = f.readlines()#读取全部内容for line in lines    print line

3、 python写文件

f = open("c:\\1.txt","r+")#可读可写模式f.write("123")#写入字符串

4、 正则表达式，读取tomcat的日志并打印日期

import reregx = "\d\d\d\d-\d\d-\d+"f = open("c:\stdout.log","r")i = 0for str in f.readlines():    if re.search(regx,str):        Response.write(str+"<br>")        if i>10:break#由于是测试，只分析十行        i=i+1f.close();

5、 连接数据库

import pgdbconn = pgdb.connect(host='localhost',databse='qingfeng',user='qingfeng',password='123')cur = conn.cursor() cur.execute("select * from dream") print cur.rowcount

6、 pythonSAX处理xml:

import stringfrom xml.sax import saxlib, saxextsclass QuotationHandler(saxlib.HandlerBase):    """Crude sax extractor for quotations.dtd document"""    def __init__(self):            self.in_quote = 0            self.thisquote = ''    def startDocument(self):        print '--- Begin Document ---'    def startElement(self, name, attrs):        if name == 'quotation':            print 'QUOTATION:'            self.in_quote = 1        else:            self.thisquote = self.thisquote + '{'    def endElement(self, name):        if name == 'quotation':            print string.join(string.split(self.thisquote[:230]))+'...',            print '('+str(len(self.thisquote))+' bytes)\n'            self.thisquote = ''            self.in_quote = 0        else:            self.thisquote = self.thisquote + '}'    def characters(self, ch, start, length):        if self.in_quote:            self.thisquote = self.thisquote + ch[start:start+length]if __name__ == '__main__':    parser  = saxexts.XMLParserFactory.make_parser()    handler = QuotationHandler()    parser.setDocumentHandler(handler)    parser.parseFile(open("sample.xml"))    parser.close()

7、python的GUI模块标准的是Tkinter,也有QT和MFC的模块，有兴趣的大家自己搜索下

import Tkinterroot=Tkinter.Tk()my=Label(root,"Welcome to python's world")my.pack()root.mainloop()