1 class ConnectionPool
 2
 3     __instance=None
 4
 5     def__init__(self):
 6         self.ip="1.1.1.1"
 7         self.port=3307
 8         self.pwd="567678"
 9         self.username="minmin"
10         self.conn_list=[1,2,3,4,5,6,7,8,9,10]
11
12
13     @staticmethond
14     def get_instance():
15         if ConnectionPool.__instance:
16             return ConnectionPool.__instance
17         else:
18             #/创建一个对象，并将对象赋值给静态字段__instance
19             ConnectionPool.__instance=ConnectionPool()
20             return ConnectionPool.__instance
21
22      def get_coonection(self):
23         #获取连接
24           import random
25           r =  random.randrange(1,11)
26               return r
27
28
29 obj1=ConnectPool.get_instance()
30 print(obj1)
31 obj2=ConnectPool.get_instance()
32 print(obj2)
33 obj3=ConnectPool.get_instance()
34 print(obj3)                                

 1 #!/usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3
 4
 5 form wsgiref.simple_server import make_server
 6 import random
 7 class ConnectionPool:
 8
 9
10     __instance = None
11
12 def __init__(self):
13     self.ip = "1.1.1.1"
14     self.port=3307
15     self.pwd="567678"
16     self.username="124"
17     self.conn_list = [1, 2, 3, 4, 5, 6, 7, 8, 9,10]
18
19
20 @staticmethod
21 def  get_instance():
22     if ConnectionPool.__instance:
23         return ConnectionPool.__instance
24     else:
25
26          # 创建一个对象，并将对象赋值给静态字段__instance
27         ConnectionPool.__instance = ConnectionPool()
28         return ConnectionPool.__instance
29
30 def get_connection(self):
31             #获取连接
32     r =  random.randrange(1,11)
33     return r
34
35 def index():
36     p = ConnectionPool.get_instance()
37     print(p)
38     conn = ConnectionPool.get_connection()
39     return "11111111111"+str(conn)
40
41 def news():
42     return "123124"
43 def RunServer(environ,start_response):
44     start_response(status='200 OK',headers=[('Content-Type','text/html')])
45     url=environ['PATH_INFO']
46     if url.endswith('index'):
47         ret = index()
48         return ret
49     elif url.endswith('news'):
50         ret = news()
51         return ret
52     else:
53         return '404'
54
55 if __name__=='__main__':
56     httpd=make_server('', 8000, RunServer)
57     print("Serving HTTP on port 8000.....")
58     httpd.serve_forever()单例单例