Python Coding challenge - Day 959| What is the output of the following Python Code?

Code Explanation:

1. Creating a Registry List

registry = []

An empty list named registry is created.

It will store the names of all subclasses of Plugin.

2. Defining the Base Class

class Plugin:

A base class named Plugin is defined.

It will automatically track all its subclasses.

3. Overriding __init_subclass__

    def __init_subclass__(cls):

        registry.append(cls.__name__)

__init_subclass__ is a special hook called every time a subclass is created.

cls refers to the newly created subclass.

The subclass name is appended to the registry list.

4. Creating Subclass A

class A(Plugin): pass

A is created as a subclass of Plugin.

This triggers:

Plugin.__init_subclass__(A)

"A" is appended to registry.

5. Creating Subclass B

class B(Plugin): pass

B is created as a subclass of Plugin.

This triggers:

Plugin.__init_subclass__(B)

"B" is appended to registry.

6. Printing the Registry

print(registry)

Prints the contents of registry.

7. Final Output

['A', 'B']

Final Answer

✔ Output:

['A', 'B']

 

800 Days Python Coding Challenges with Explanation