def create_acct_id(model_data):
    """
    Given model data, create new account id that is just the max existing +1
    """
    # Get max account id
    max_acct_id = model_data.agg({'account_id': 'max'}).collect()[0][0]

    # New Account id
    new_acct_id = max_acct_id + 1

    return new_acct_id