How to make a class JSON serializable

Question

How to make a Python class serializable?

A simple class:

class FileItem:     def __init__(self, fname):         self.fname = fname 

What should I do to be able to get output of:

>>> import json  >>> my_file = FileItem('/foo/bar') >>> json.dumps(my_file) TypeError: Object of type 'FileItem' is not JSON serializable 

Without the error

Answer 1

Here is a simple solution for a simple feature:

.toJSON() Method

Instead of a JSON serializable class, implement a serializer method:

import json  class Object:     def toJSON(self):         return json.dumps(self, default=lambda o: o.__dict__,              sort_keys=True, indent=4) 

So you just call it to serialize:

me = Object() me.name = "Onur" me.age = 35 me.dog = Object() me.dog.name = "Apollo"  print(me.toJSON()) 

will output:

{     "age": 35,     "dog": {         "name": "Apollo"     },     "name": "Onur" }