Python 常用的代码

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.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.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 re

     regx = "\d\d\d\d-\d\d-\d+"

     f = open("c:\stdout.log","r")

     i = 0

     for 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+1

     f.close();

 

5.连接数据库

 

import pgdb

 

conn = pgdb.connect

 

(host='localhost',databse='qingfeng',user='qingfeng',password='123')

 

        cur = conn.cursor()

 

        cur.execute("select * from dream")

 

        print cur.rowcount

 

6.SAX处理xml:

 

      import string

      from xml.sax import saxlib, saxexts

 

      class 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 Tkinter

 

        root=Tkinter.Tk()

 

        my=Label(root,"Welcome to python's world")

 

        my.pack()

 

        root.mainloop()