Get and set class properties

Overload __getattr__ and __setattr__

We can add properties to old-style classes. with magic methods rather than the property function.

The following four methods provide all the functionality you need in old-style classes.

• __getattribute__(self, name) is called when the attribute name is accessed. Works correctly on new-style classes only.
• __getattr__(self, name) is called when the attribute name is accessed and the object has no such attribute.
• __setattr__(self, name, value) is called when an attempt is made to bind the attribute name to value.
• __delattr__(self, name) is called when an attempt is made to delete the attribute name.

class Rectangle: 
    def __init__(self): 
        self.width = 0 # from ww w.ja va 2 s .com
        self.height = 0 
    def __setattr__(self, name, value): 
        if name == 'size': 
            self.width, self.height = value 
        else: 
            self.__dict__[name] = value 
    def __getattr__(self, name): 
        if name == 'size': 
            return self.width, self.height 
        else: 
            raise AttributeError