crear un login y archivos Json

import json
import os

# function to create a user
def create_user(username, password):
  if os.path.exists(username + ".json"):
    print("user already exists")
  else:
    with open(username + ".json", "w") as file:
      json.dump({
          "username": username,
          "password": password,
          "balance": 0
      }, file)
      
# function to validate a user
def validate_user(username, password):
  if os.path.exists(username + ".json"):
    with open(username + ".json") as file:
      data = json.load(file)
      if data["password"] == password:
        return True
      else:
        return False
  else:
    return False

# function to deposit money
def deposit_money(username, amount):
  if os.path.exists(username + ".json"):
    with open(username + ".json") as file:
      data = json.load(file)
      data["balance"] =