def is_prime(number):
    """Return True if *number* is prime."""
    if (number <= 0):
        raise ValueError("Negative numbers or 0 not allowed")
    if (round(number) != number):
        raise ValueError("This functions is for integers only")
    if number == 1: return False
    
    
    for element in range(2,number):
        if number % element == 0:
            return False
    return True