def generate_id(number_of_small_letters = 4,
                number_of_capital_letters = 2,
                number_of_digits = 2,
                number_of_special_chars = 2,
                allowed_special_chars = r"_+-!"):

    lower_letters = string.ascii_lowercase
    lower_upper = string.ascii_uppercase
    numbers = range(10)
    special_characters = [char for char in allowed_special_chars]

    arr = get_combination(lower_letters, number_of_small_letters)
    arr += get_combination(lower_upper, number_of_capital_letters)
    arr += get_combination(numbers, number_of_digits)
    arr += get_combination(special_characters, number_of_special_chars)

    random.shuffle(arr)

    return ''.join(arr)