List of objects to JSON with Python

Question

I have a problem converting Object instances to JSON:

ob = Object()

list_name = scaping_myObj(base_url, u, number_page)

for ob in list_name:
          


        

Answer 1

You can use a list comprehension to produce a list of dictionaries, then convert that:

json_string = json.dumps([ob.__dict__ for ob in list_name])

or use a default function; json.dumps() will call it for anything it cannot serialise:

def obj_dict(obj):
    return obj.__dict__

json_string = json.dumps(list_name, default=obj_dict)

The latter works for objects inserted at any level of the structure, not just in lists.

Personally, I'd use a project like marshmallow to handle anything more complex; e.g. handling your example data could be done with

from marshmallow import Schema, fields

class ObjectSchema(Schema):
    city = fields.Str()
    name = fields.Str()

object_schema = ObjectSchema()
json_string = object_schema.dumps(list_name, many=True)