Python Coding challenge - Day 975| What is the output of the following Python Code?

 

Code Explanation:

1. Defining a Custom Metaclass

class Meta(type):

Meta is a metaclass because it inherits from type.

A metaclass controls class-level behavior.

2. Overriding __instancecheck__

    def __instancecheck__(cls, obj):

        return False

__instancecheck__ is a special method used by isinstance(obj, cls).

By overriding it, we can control the result of isinstance.

This implementation always returns False, no matter the object.

3. Defining Class A Using the Metaclass

class A(metaclass=Meta): pass

Class A is created with Meta as its metaclass.

Any isinstance(..., A) check will now use Meta.__instancecheck__.

 4. Checking the Instance

print(isinstance(A(), A))

Step-by-step:

A() creates an instance of class A.

isinstance(A(), A) calls:

Meta.__instancecheck__(A, obj)

The method returns False.

 5. Final Output

False

Final Answer

✔ Output:

False

400 Days Python Coding Challenges with Explanation