Parse JSON and store data in Python Class

Question

This is my JSON data

[
    {
        "id":1,
        "name":"abc",
        "phone": "12345",
        "Charecteristics": [
            {
                "id":1,
                "name":"Good Looking",
                "rating": "Average",
            }
            {
                "id":2,
                "name":"Smart",
                "rating": "Excellent",
            }
        ]
    },
    { ... },
    { ... }
]

I have two Classes in Python

class Character(object):
    id = 0
    name = ""
    rating = ""

class Person(object):
    id = 0
    name = ""
    phone = ""
    Characteristics = []

I need to parse the JSON data and instantiate appropriate Classes. The Classes are self-explanatory: i.e. Person has an array of Character classes.

How do I instantiate these and store data appropriately?

Also, how will I access particular Person data? i.e. Person's details and characteristics

Similar question: http://stackoverflow.com/questions/3847399/convert-a-json-string-to-python-object — Don, Sep 11 '12 at 13:15
Note that your JSON example is rather malformed. Apart from the odd quotes you've used, you cannot have multiple `Character` keys in the `Charecteristics` object either. — Martijn Pieters, Sep 11 '12 at 13:20
I've cleaned up your JSON to actually be valid; note that I've turned both the group of persons and group of characteristics into lists (as they would normally be). — Martijn Pieters, Sep 11 '12 at 13:32
@Tichodroma: I'll surely do more research the next time.. Sorry I didnt find the similar question at my first few tries. — Kartik Rokde, Sep 11 '12 at 17:10
See [JSON data into a Python object](https://stackoverflow.com/questions/6578986/how-to-convert-json-data-into-a-python-object/66054047#66054047) — Milovan Tomašević, Feb 04 '21 at 21:46

score 13 · Accepted Answer · edited Dec 10 '17 at 12:26

13

Take a look at colander; it makes turning a JSON data structure into Python objects dead easy.

You define a schema:

import colander


class Characteristic(colander.MappingSchema):
    id = colander.SchemaNode(colander.Int(),
                             validator=colander.Range(0, 9999))
    name = colander.SchemaNode(colander.String())
    rating = colander.SchemaNode(colander.String())        


class Characteristics(colander.SequenceSchema):
    characteristic = Characteristic()


class Person(colander.MappingSchema):
    id = colander.SchemaNode(colander.Int(),
                             validator=colander.Range(0, 9999))
    name = colander.SchemaNode(colander.String())
    phone = colander.SchemaNode(colander.String())
    characteristics = Characteristics()


class Data(colander.SequenceSchema):
    person = Person()

then pass in your JSON data structure using the following:

deserialized = Data.deserialize(json.loads(json_string))

edited Dec 10 '17 at 12:26

Jolley71717

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answered Sep 11 '12 at 13:24

Martijn Pieters

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Thanks.. :-) I'm new to Python but have to work with web services,, so using dJango.. Pls consider me amateur.. One more question.. – Kartik Rokde Sep 11 '12 at 18:20
22

Thats not dead easy. Dead easy would be if it generated python classes given a particular JSON string. – Vanuan Nov 27 '12 at 20:13
@Vanuan anything that does that? – Jonathan Apr 30 '17 at 15:36
1

@Jonathan The closest is this https://github.com/cwacek/python-jsonschema-objects But it still requires specifying types for each field. – Vanuan May 03 '17 at 12:11
Thanks @Vanuan, it looks really promising! – Jonathan May 04 '17 at 10:28

lovasoa · Answer 2 · 2020-02-22T20:49:04.767

6

If you are writing in python 3.6+, the easiest is probably to use marshmallow-dataclass :

from marshmallow_dataclass import dataclass
from typing import List

@dataclass
class Character:
    id : int
    name : str
    rating : str

@dataclass
class Person:
    id : int
    name : str
    phone : str
    characteristics : List[Character]

my_person = Person.Schema().loads(json_str)

edited Feb 22 '20 at 20:49

answered Feb 24 '19 at 13:24

lovasoa

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Parse JSON and store data in Python Class

2 Answers2

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