PYTHON__ Advanced: __getattribute__ Methods for classes

Tag: UNC LSE Item function code CEE recursive maximum result

In the class, there is no way this thing, all things are stored in the attribute, the so-called call method is actually a class inside the name of a property pointed to a function (method), the return is a function of the reference, and then use the function () this way can call it

When invoking the method of an instance, it is actually a string that passes through the object.

For example, T = Test (), assuming that Func is a method of the Test class, then T.func () is passing a ' func ' string to the class's __getattribute__ method, and after processing it returns a reference to the Func function, and finally F UNC () calls this function (method)

classtest:def __init__ (self): SELF.A= -self.b= $def __getattribute__ (self, item):ifitem = ='a': Print ('------%s------'%Item)return '%s is get'%ItemElse:            return Object. __getattribute__ (self, item) T=Test () print (T.A)>>>------a------a is Get

Whether you invoke a property or a method, you first force the call to the __getattribute__ method, and then return the value of the property or a reference to the function (method).

note that in the __getattribute__ method it is a bad behavior to use a similar self.***, because each invocation of the class's properties forces the call to __getattribute__. Therefore, it is very possible to cause recursive calls.

classtest:def __getattribute__ (Self, item):ifitem = ='a': Print ('------%s------'%Item)return '%s is get'%ItemElse:            returnSelf.test # <----------------------------------------------------------------------------def test (self): Print ('.........') T=Test () print (t.b)>>>recursionerror:maximum recursion depth exceededinchComparison

Self.test will call __getattribute__ again, and the end result is a recursive exception: the maximum recursion depth exceeds what ....

PYTHON__ Advanced: __getattribute__ Methods for classes