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()