How to write to the database in json format certain indexes and values ​​from a list in python?

Question

Python

The essence of the question is as follows,
in php it is enough just to write such an array:
$data = [
'0' => 1,
'4' => 2,
'7' => 3
];
json_encode($data); and write to the database.
How can you write the same format only in python? That is, preserving the order of the array keys.

Answer 1

I believe that it is not enough to write to the database even in php $data = ['0'=>1, '4'=>2]
In python, it is done something like this:

import json

data = {'0': 1, '4': 2}
instance.field_name = json.dumps(data)
instance.save()

You can also use a JSONField field , then reading/writing json will be transparent:

from django.contrib.postgres.fields import JSONField
from django.db import models

class CustomModel(models.Model):
    json_field_name = JSONField()

instance = CustomModel()
instance.field_name = {'0': 1, '4': 2}
instance.save()

You can only preserve the order of the keys if you use an OrderedDict , however this does not guarantee that the order will be preserved when saved to JSON and read. It is better to slightly change the data format for such purposes, for example, use a list:
data = [{'0': 4}, {'4': 2}]