Serializing Python data Correctly (JSON)

[JgKSuperstar]

You can't append to JSON data like a log file or a database. If you want to add data to it you need to:
* read in the existing data to a list or dict
* append or add your data to that object
* dump the json again (which has all the information).

With a database you could just do the 'insert' and have it keep track of the old data. JSON can't do that.

Instead of a user list you should have a user dictionary.

This is a quick and ugly example:

import sys
import json
from dataclasses import dataclass

@dataclass
class Account():
    firstName:str
    lastName:str
    email:str
    username:str
    password:str

class AccountManagement:
    def __init__(self):
        self.PendingUsers = {}

    def CreateAccount(self, user_id, firstName, lastName, email, username, password):
        self.PendingUsers[user_id] = Account(firstName, lastName, email, username, password)

    def WriteFile(self):
        users = {id: user.__dict__ for id, user in self.PendingUsers.items()}
        json.dump(users, sys.stdout)

accounts = AccountManagement()
accounts.CreateAccount(1, "a", "b", "c", "d", "e")
accounts.CreateAccount(2, "A", "B", "C", "D", "E")
accounts.WriteFile()

I think there are packages that make data dictionaries serializable. Using one of those is better than my __dict__ trick. You might also want to look at pydantic which makes a dataclass like thing that is serializeable to/from json.

Thank you very much. I also didn't know about the @dataclass decorator. I can learn about it in detail now :)