users_db = [
    {'id': 'ax123', 'money': 5},
    {'id': 'z5541', 'money': 0}
]

def get_user_by_id(user_id):
    for user in users_db:
        if user['id'] == user_id:
            return user
        
def send_money(from_id, to_id, amount):
    from_user_a = get_user_by_id(from_id)
    to_user_b = get_user_by_id(to_id)

    if from_user_a and to_user_b:
        if from_user_a['money'] >= amount:
            from_user_a['money'] -= amount
            to_user_b['money'] += amount
        else:
            print('the amount of money is large than your balance')
        
    

send_money('ax123', 'z5541', 2)
send_money('ax123', 'z5541', 2)
print(users_db)