#!/bin/bash

# ideone boilerplate: run in temp dir
t=$(mktemp -d -t ideone.XXXXXXXX) || exit
trap 'rm -rf "$t"' ERR EXIT
cd "$t"

mkdir -p Data

cat <<\: >Data/Insta-database.json
{
    "data": [
        {
            "name": "quesa",
            "surname": "fum"
        },
        {
            "name": "hau",
            "surname": "guygo",
            "salary": "213,324",
            "interest": "5%"
        },
        {
            "name": "ksmair",
            "surname": "bree",
            "salary": "943,229",
            "interest": "15%"
        }
    ]
}
:

cat <<\: >demo.py
import json


export_dict = {'salary': 123456, 'interest': 0.123}

with open('Data/Insta-database.json', 'r') as inputfile:
    file = json.load(inputfile)

for elem in file['data']:
    elem.update(export_dict)

with open('Data/Insta-database.json', 'w') as outfile: 
    json.dump(file, outfile, indent = 4)
:

python3 demo.py

cat Data/Insta-database.json