How do I write a long integer as binary in Python?

Question

In Python, long integers have unlimited precision. I would like to write a 16 byte (128 bit) integer to a file. struct from the standard library supports only u

Answer 1

This may not avoid the "mask and shift each integer" requirement. I'm not sure that avoiding mask and shift means in the context of Python long values.

The bytes are these:

def bytes( long_int ):
    bytes = []
    while long_int != 0:
        b = long_int%256
        bytes.insert( 0, b )
        long_int //= 256
    return bytes

You can then pack this list of bytes using struct.pack( '16b', bytes )