def factorial(number):
    """Function that finds the factorial number of the number introduced

    Args:
        number (int): Number that you want to find the factorial of

    Raises:
        ValueError: if the value of number is less than 0 it raises this error with a warning

    Returns:
        int: Factorial of {number}
    """
    if number < 0:
        raise ValueError(
            'Introdujo un numero negativo [' + str(number) + '] intente de nuevo')
    if number <= 0:
        return 1
    else:
        return number * factorial(number - 1)