Non-math-geek needs help with CRCs (binascii.crc32)
get at bent.com
Wed Apr 7 11:31:01 CEST 2004
1) Does anyone know if the CRC32 algorithm in binascii has a name? There
seem to be a TON of different CRC32 methods; different polynomials,
different byte orders, different seeds, some flip the bits and some XOR the
result with something else.
I've been looking around and a lot of documents (RFCs, etc) refer to ISO3309
and/or ITU-T V.42 (neither of which appear to be available without paid
access), yet are often incompatible with each other. So unless they're
lying, I assume ISO3309 allows for the above variations, and specifying an
ISO3309 CRC32 doesn't narrow it down any.
2) With Python 2.4 and its signed hex(), what's the 'best'/shortest
(preferably one operation, without any if x < 0 business) way to get an
unsigned 32bit CRC?
More information about the Python-list