Checksum only python native module

I tried to find a quick python native implemenation of ip checksum to achieve a better performance - I Didn't find any, so I created my own module.

Calculate IP checksum-16 (Host endianess for compatability with other pure python implementations:

How to use

from checksum import checksum
res = checksum(b'BEST DATA')

The module also supports partial checksums:

from checksum import checksum
res = checksum(b'BEST DATA')
res = checksum(b'ANOTHER BULK OF GREAT DATA', res)