Python 常用代码片段

[代码] [Python]代码
01    1.生成随机数
02              import random    #这个是注释，引入模块
03              rnd = random.randint(1,500)#生成1-500之间的随机数
04    
05    2.读文件
06    
07             f = open("c:\\1.txt","r")
08             lines = f.readlines()#读取全部内容
09             for line in lines
10                     print line
11    3.写文件
12            f = open("c:\\1.txt","r+")#可读可写模式
13            f.write("123")#写入字符串
14    
15    4.正则表达式，读取tomcat的日志并打印日期
16    
17         import re
18         regx = "\d\d\d\d-\d\d-\d+"
19         f = open("c:\stdout.log","r")
20         i = 0
21         for str in f.readlines():
22            if re.search(regx,str):
23                 Response.write(str+"<br>")
24                  if i>10:break#由于是测试，只分析十行
25                  i=i+1
26         f.close();
27    
28    5.连接数据库
29    
30    import pgdb
31    
32    conn = pgdb.connect
33    
34    (host='localhost',databse='qingfeng',user='qingfeng',password='123')
35    
36            cur = conn.cursor()
37    
38            cur.execute("select * from dream")
39    
40            print cur.rowcount
41    
42    6.SAX处理xml:
43    
44          import string
45          from xml.sax import saxlib, saxexts
46    
47          class QuotationHandler(saxlib.HandlerBase):
48              """Crude sax extractor for quotations.dtd document"""
49    
50              def __init__(self):
51                      self.in_quote = 0
52                      self.thisquote = ''
53    
54              def startDocument(self):
55                  print '--- Begin Document ---'
56    
57              def startElement(self, name, attrs):
58                  if name == 'quotation':
59                      print 'QUOTATION:'
60                      self.in_quote = 1
61                  else:
62                      self.thisquote = self.thisquote + '{'
63    
64              def endElement(self, name):
65                  if name == 'quotation':
66                      print string.join(string.split(self.thisquote[:230]))+'...',
67                      print '('+str(len(self.thisquote))+' bytes)\n'
68                      self.thisquote = ''
69                      self.in_quote = 0
70                  else:
71                      self.thisquote = self.thisquote + '}'
72    
73              def characters(self, ch, start, length):
74                  if self.in_quote:
75                      self.thisquote = self.thisquote + ch[start:start+length]
76    
77          if __name__ == '__main__':
78              parser  = saxexts.XMLParserFactory.make_parser()
79              handler = QuotationHandler()
80              parser.setDocumentHandler(handler)
81              parser.parseFile(open("sample.xml"))
82              parser.close()
83    
84    
85    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
86    
87            import Tkinter
88    
89            root=Tkinter.Tk()
90    
91            my=Label(root,"Welcome to python's world")
92    
93            my.pack()
94    
95            root.mainloop()