property装饰器简化类里实例set，get调用

Posted 2022-06-30 hell-west-road

一般工厂函数使用set方法设置数据，get方法获取结果，例如：

 1 from collections import namedtuple
 2 
 3 class Nodes(object):
 4     def __init__(self, getIp):
 5         self.nodes = None
 6         self.node = None
 7         self.getIp = getIp
 8 
 9     def setNodes(self, nodes):
10         self.nodes = nodes
11 
12     def getNode(self):
13         for i in self.nodes:
14             if i.ip == self.getIp:
15                 self.node = i
16                 break
17         return self.node
18 
19 if __name__ == "__main__":
20     myOpt = namedtuple(‘node‘, ‘ip port user‘)
21     nodes = [
22         myOpt(‘192.168.1.1‘, 22, ‘guest‘),
23         myOpt(‘192.168.1.2‘, 22, ‘guest‘),
24     ]
25     myNode = Nodes(‘192.168.1.1‘)
26     myNode.setNodes(nodes)
27     print(myNode.getNode())

set和get方法两者没有对应关系相互独立，另外一个坏处，随着类函数越多set和get的方法越多，不利于阅读

property：

 1 from collections import namedtuple
 2 
 3 class Nodes(object):
 4     def __init__(self, getIp):
 5         self.nodes = None
 6         self.node = None
 7         self.getIp = getIp
 8 
 9     @property
10     def getNodes(self):
11         for i in self.nodes:
12             if i.ip == self.getIp:
13                 self.node = i
14                 break
15         return self.node
16 
17     @getNodes.setter
18     def getNodes(self, nodes):
19         self.nodes = nodes
20 
21 if __name__ == "__main__":
22     myOpt = namedtuple(‘node‘, ‘ip port user‘)
23     nodes = [
24         myOpt(‘192.168.1.1‘, 22, ‘guest‘),
25         myOpt(‘192.168.1.2‘, 22, ‘guest‘),
26     ]
27     myNode = Nodes(‘192.168.1.1‘)
28     myNode.getNodes = nodes
29     print(myNode.getNodes)

set和get方法对应的方法名相同，设置数据和获取结果调用相同的方法名