Le mardi 6 mars 2018 09:26:50 UTC+1, Sébastien Boisgérault a écrit : > Le mardi 6 mars 2018 00:29:25 UTC+1, Roel Schroeven a écrit : > > Sébastien Boisgérault schreef op 5/03/2018 20:05: > > > I have released bitstream, a Python library to manage binary data (at the > > > byte or bit level), > > > hopefully without the pain that this kind of thing usually entails :) > > > > > > If you have struggled with this topic in the past, please take a look at > > > the documentation > > > (http://boisgera.github.io/bitstream/) and tell me what you think. > > > > Hi Sébastien, > > > > At work I have some Python code to decode AIS messages, for which I > > created my own code for handling binary data. It works, but is pretty > > slow. Not surprising, since handling data at the bit level is not > > exactly Python's strength. If I find the time, I'll try to replace my > > code with your bitstream and see if it does what I need it to do, and if > > it's any faster. > > > > If/when I actually get around to it, I'll keep you informed. > > > >  https://en.wikipedia.org/wiki/Automatic_identification_system > > > > > > Best regards, > > Roel > > > > -- > > The saddest aspect of life right now is that science gathers knowledge > > faster than society gathers wisdom. > > -- Isaac Asimov > > > > Roel Schroeven > > Great, thanks !
Hi again Roel, I had a look at the AIS message format from your link (https://en.wikipedia.org/wiki/Automatic_identification_system#Message_format) and this seems to be a nice use case; all the data components seem to be nicely aligned on the byte boundary ... until you see that the payload uses ASCII6(*), which I didn't know about. Thanks again for the info! Cheers, (*) ASCII6 code = ASCII code + 48; (http://catb.org/gpsd/AIVDM.html#_aivdm_aivdo_sentence_layer) SB -- https://mail.python.org/mailman/listinfo/python-list