oops.txt

classes
obj





@abstractmethod

_   ->
__  -> private  accessed using objname.classnaem.__
__xx__


MRO for multiple inheritance

method resolution order -> Cat(Tiger, Animal) -> Cat tiger ANinmal 


Cat(ANinmal, Tiger ) -> gives error , bcoz python gives prefernece to child first.


Can't instantiate abstract class A with abstract methods row



it uses the value of x which is defined in main program (i.e. outside the class ). If x = 20
is not defined, then NameError will be generated.





Multiple constructor using ‘classmethod’
->
which can directly call constructor using cls from classmethod, so it is liking multiple constructor.

classmethods can be called using classname.

_
__ -> not private but used for identification of variables,

if parent and child use same variables, there will be a problem, so __ is used to identify. _ClassName__variable

@property -> if a method is given a @property tag, then it can be called as a attribute.

• @property decorator allows . operator to call the function. Here, self.radius will call the method radius,
which returns the self._radius. Hence, _radius is stored in the dictionary instead of dict.
• If we use ‘return self.radius’ instead of ‘return self._radius’, then the @property will result in infinite loop
as self.property will call the property method, which will return self.property, which results in calling the
@property again.
• Further, we can use @property for type checking, validation or performing various operations by writing
codes in the setter method e.g. change the date to todays date etc.


Decorators -> Decorator is a function that creates a wrapper around another function. This wrapper adds some additional
functionality to existing code.


super always calls the immediate superclass

In multiple inheritances, the methods are executed based on the order specified while inheriting the classes.