How to Add Multiple Values in Json Object and Get an Updated Json File

How to add multiple values in JSON object and get an updated json file

You can use .hasOwnProperty on that object to find out which object don't have property gender and iteratively add it and write back into the file again!

Here's a code snippet to help you get started.

const fs = require('fs');
const util = require('util');

// Promisify fs api(s)
const readFileAsync = util.promisify(fs.readFile);
const writeFileAsync = util.promisify(fs.writeFile);

// IIFE to read the file, find the objects which has missing properties, add them and write them back
(async function() {
    try {
        const fileContents = await readFileAsync('data.json');
        const fileData = JSON.parse(fileContents);

        const remainingData = fileData.filter(x => !x.hasOwnProperty('gender'));

        remainingData.forEach(x => x.gender = 'Male');

        await writeFileAsync('data.json', JSON.stringify(fileData, null, 4));

    } catch(err) {
        console.log(`Failed because: {err}!`)
    }
})();

How to modify the multiple values in the JSON file using python

The code works as expected if you have resolved the variable name difference.

Further, I would also suggest to open the file using context manager with so that it gets closed automagically when the with block is exited.

import json, os
with open(".\example.json", 'r') as f:
    data = json.load(f)

for feature in data['images']:
    feature['file_name'] = os.path.basename(feature["file_name"])
    
print(data)

Output:

Data in json file:

{'images': [{'id': 1, 'file_name': 'Folder1/Folder2/Folder3/Folder4/1110.jpg', 'height': 3024, 'width': 4032}, {'id': 2, 'file_name': 'Folder1/Folder2/Folder3/Folder4/1111.jpg', 'height': 3024, 'width': 4032}, {'id': 3, 'file_name': 'Folder1/Folder2/Folder3/Folder4/1112.jpg', 'height': 3024, 'width': 4032}]}

Formatted data:

{'images': [{'id': 1, 'file_name': '1110.jpg', 'height': 3024, 'width': 4032}, {'id': 2, 'file_name': '1111.jpg', 'height': 3024, 'width': 4032}, {'id': 3, 'file_name': '1112.jpg', 'height': 3024, 'width': 4032}]}

How to create array of JSON objects with multiple values?

In python, the curly brackets { } are used for dictionaries, which are similar to javascript objects (which sounds like what you're familiar with). The hard brackets [ ] are called lists. Your desired response looks like a dictionary with a key that has a dictionary as its value. Unfortunately, you can't add key-value pairs into a list or array in python, so you should instead make another dictionary instead of a list or rethink what your desired list would look like (perhaps only the values and not the keys).

TL;DR: you are appending dictionaries to your list:
.append({obj[0]: obj[1]})

{obj[0]: obj[1]} is a dictionary you are appending to the list.
In python you can have a list of dictionaries but you cant have just key-value pairs in a list

How to add multiple objects into a single array in a JSON file using Python?

You can use:

import json
from os import path

users = [
    {
        "username": "",
        "phone": ""
    }
]

username = input('Username: ')
phone = input('Phone: ')
for user in users:
    user['username'] = username
    user['phone'] = phone
    
my_path = 'users.json'
if path.exists(my_path):
    with open(my_path , 'r') as file:
        previous_json = json.load(file)
        users = previous_json + users
        
with open(my_path , 'w') as file:
    json.dump(users, file, indent=4)

In your code, you are just appending every entry to your file on each run of your code. To have only one list with all your entries, you have to first read the previous entries and then add the new entry.

Create JSON with multiple values

You need to check the size of the current object, and insert the data to the position of that size:

$(document).ready(function() {  var maj = {};
  $("#btnSubmitRejetRefModele").click(function() {    var size = Object.keys(maj).length;    var data = {      one: 'a' + (size+1),      two: 'b' + (size+1),      three: 'c' + (size+1)    }    maj[size] = data;    console.clear();    console.log(maj);  });});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script><button id="btnSubmitRejetRefModele">Add</button>

{
    "cars": {
        "Nissan": [
            {"model":"Sentra", "doors":4},
            {"model":"Maxima", "doors":4},
            {"model":"Skyline", "doors":2}
        ],
        "Ford": [
            {"model":"Taurus", "doors":4},
            {"model":"Escort", "doors":4}
        ]
    }
}

data.cars['Nissan'][0].model   // Sentra
data.cars['Nissan'][1].model   // Maxima
data.cars['Nissan'][2].doors   // 2

for (var make in data.cars) {
    for (var i = 0; i < data.cars[make].length; i++) {
        var model = data.cars[make][i].model;
        var doors = data.cars[make][i].doors;
        alert(make + ', ' + model + ', ' + doors);
    }
}

{
    "cars": {
        "Nissan": {
            "Sentra": {"doors":4, "transmission":"automatic"},
            "Maxima": {"doors":4, "transmission":"automatic"}
        },
        "Ford": {
            "Taurus": {"doors":4, "transmission":"automatic"},
            "Escort": {"doors":4, "transmission":"automatic"}
        }
    }
}

data.cars['Nissan']['Sentra'].doors   // 4
data.cars['Nissan']['Maxima'].doors   // 4
data.cars['Nissan']['Maxima'].transmission   // automatic

for (var make in data.cars) {
    for (var model in data.cars[make]) {
        var doors = data.cars[make][model].doors;
        alert(make + ', ' + model + ', ' + doors);
    }
}

model.IDCliente = StartID;
var fileName = @"D:\AnagraficaClientiJsonMemory\clienti.txt";
var fileContent = File.ReadAllText(fileName);
var models = JsonConvert.DeserializeObject<List<ClienteModel>>(fileContent);
models.Add(model);
File.WriteAllText (fileName, JsonConvert.SerializeObject(models));
MessageBox.Show("Cliente aggiunto correttamente.");