def int2bytes(number, fill_size=None, chunk_size=None, overflow=False):
    if number < 0:
        raise ValueError("Number must be an unsigned integer: %d" % number)

    if fill_size and chunk_size:
        raise ValueError("You can either fill or pad chunks, but not both")

    # Ensure these are integers.
    number & 1

    raw_bytes = b('')

    # Pack the integer one machine word at a time into bytes.
    num = number
    word_bits, _, max_uint, pack_type = get_word_alignment(num)
    pack_format = ">%s" % pack_type
    while num > 0:
        raw_bytes = pack(pack_format, num & max_uint) + raw_bytes
        num >>= word_bits
    # Obtain the index of the first non-zero byte.
    zero_leading = bytes_leading(raw_bytes)
    if number == 0:
        raw_bytes = ZERO_BYTE
    # De-padding.
    raw_bytes = raw_bytes[zero_leading:]

    length = len(raw_bytes)
    if fill_size and fill_size > 0:
        if not overflow and length > fill_size:
            raise OverflowError(
                "Need %d bytes for number, but fill size is %d" %
                (length, fill_size)
            )
        raw_bytes = raw_bytes.rjust(fill_size, ZERO_BYTE)
    elif chunk_size and chunk_size > 0:
        remainder = length % chunk_size
        if remainder:
            padding_size = chunk_size - remainder
            raw_bytes = raw_bytes.rjust(length + padding_size, ZERO_BYTE)
    return raw_bytes
Convert an unsigned integer to bytes (base-256 representation)::
dataset/ETHPy150Open CouchPotato/CouchPotatoServer/libs/rsa/transform.py/int2bytes