def is_pandigital(value):
    """
    Check that each digit appears once only.

    :param value: integer value (can also be negative)
    :retuns: true when given number is pandigital

    see http://en.wikipedia.org/wiki/Pandigital_number

    >>> is_pandigital(1234567890)
    True
    >>> is_pandigital(12345678900)
    False
    >>> is_pandigital(9876543210)
    True
    >>> is_pandigital(10240)
    False
    """
    value = abs(value)
    digits = set()
    counter = 0
    while value > 0:
        digits.add(value % 10)
        counter += 1
        value //= 10
    return counter == len(digits)