Class is a collection of data (variables and methods). It bundles data and functionality together. It provides all standard features of object-oriented programming. Basically it is a blueprint for creating objects. Creating a new class creates a new type of object, allowing new instances of that type to be made.
Example:
Output:
The value of a: 7
__subclasscheck__ in Python
__subclasscheck__ is one of the methods to customize the result of
issubclass() built-in function. It is a method to check whether a class is a subclass or not and returns
True if the class is considered as a subclass(direct or indirect) of another class, otherwise, returns
False. It cannot be defined as a class method in the actual/real class. It is implemented in the metaclass, as it is not for ordinary classes. Consider the below example for better understanding.
Example: Consider a situation where you want to check if a certain value is present as an attribute inside a class using the
issubclass() method.
Output:
True
False
True
__subclasshook__ in Python
Abstract class can override
__subclasshook__() method to customize
issubclass(). It returns
True when a class is found to be subclass of a ABC class, it returns
False if it is not and returns NotImplemented if the subclass check is continued with the usual mechanism. This method is defined in the ABC class with some conditions. Classes that follow those conditions are considered to be a subclass.
Note: It must be defined as a class method.
Example:
