Convert a Python Enum to JSON

A trivial way to make a Python Enum which is based on string tokens JSON-serializable is to inherit both str and Enum. Look at the example below for some pointers.

How?

I’ve prepared a quick demo below. Once I figured it out I laughed at myself for not seeing it earlier.

pet.py[code]

from enum import Enum

class PetType(str, Enum):
    CAT: str = "cat"
    DOG: str = "dog"

Let’s test it out in our interpreter

>>> import json
>>> import pet
>>> json.dumps([pet.PetType.CAT, pet.PetType.DOG])
'["cat", "dog"]'

It’s really that easy!
No need for a custom JSONEncoder, str is already serializable. The built in IntEnum works the same way, in fact that’s how I figured it out.

Taking it further

This applies for other classes as well. E.g. let a class inherit dict to gain it’s properties; including JSON serialization with the default encoder.