_getattr__和__setattr__可以用来对属性的设置和取值进行处理，比如下面的例子：
class
Book(object):
def __setattr__ (self, name, value):
if name == ' value ' :
object. __setattr__ (self, name, value - 100 )
else :
object. __setattr__ (self, name, value)
def __getattr__ (self, name):
try :
return object. __getattribute__ (name)
except :
return name + ' is not found! '
def __str__ (self):
return self.name + ' cost : ' + str(self.value)
c = Book()
c.name = ' Python '
c.value = 100
print c.name
print c.value
print c
print c.Type
def __setattr__ (self, name, value):
if name == ' value ' :
object. __setattr__ (self, name, value - 100 )
else :
object. __setattr__ (self, name, value)
def __getattr__ (self, name):
try :
return object. __getattribute__ (name)
except :
return name + ' is not found! '
def __str__ (self):
return self.name + ' cost : ' + str(self.value)
c = Book()
c.name = ' Python '
c.value = 100
print c.name
print c.value
print c
print c.Type
上面的例子中，在赋值书的value属性时，偷偷的将value减去了１００，呵。输出结果：
0
Python cost : 0
Type is not found!
Python 天天美味系列（总）
Python 天天美味(26) - __getattr__与__setattr__
Python 天天美味(27) - 网络编程起步(Socket发送消息)
...
本文转自CoderZh博客园博客，原文链接：http://www.cnblogs.com/coderzh/archive/2008/05/25/1206931.html，如需转载请自行联系原作者
