Restrict input type to the natural numbers (0, 1, 2, 3...)

def natural(value, argument='argument'):
    """ Restrict input type to the natural numbers (0, 1, 2, 3...) """
    value = _get_integer(value)
    if value < 0:
        error = ('Invalid {arg}: {value}. {arg} must be a non-negative '
                 'integer'.format(arg=argument, value=value))
        raise ValueError(error)
    return value