Need to convert an arbitrary byte-pair to an int.

[Richard Brodie]

"Graham Nicholls" <graham at rockcons.co.uk> wrote in message
news:3f323dc2$0$10775$afc38c87 at auth.uk.news.easynet.net...

> I'm trying to size a jpeg file.  The file size is held in a short (2 byte
> integer) at a certain offset.  Once I've found these two bytes (they're in
> MSB,LSB order), I need to convert them to an integer - now I know that in C
> I'd just cast a pointer to the offset to a short, and that python doesn't
> cast, so how can I extract the value from a stream of bytes.  I've looked
> at python.org/Doc/current (I'm using 2.3b1), but can't find anything
> obvious.

For rolling your own direct handling of byte streams, the struct module is
often best. You also might want to look at the Python Imaging Library
http://www.pythonware.com/products/pil/