Bob Greschke <[EMAIL PROTECTED]> wrote:
> This is the idea
>
> Block = pack("240s", "")
> Block[0:4] = pack(">H", W)
> Block[4:8] = pack(">H", X)
> Block[8:12] = pack(">B", Y)
> Block[12:16] = pack(">H", Z))
>
> but, of course, Block, a str, can't be sliced.
You could do this (note anonymous mappings require python 2.5)
>>> from mmap import mmap
>>> from struct import pack
>>> W,X,Y,Z=1,2,3,4
>>> Block = mmap(-1, 1024)
>>> Block[0:2] = pack(">H", W)
>>> Block[4:6] = pack(">H", X)
>>> Block[8:9] = pack(">B", Y)
>>> Block[12:14] = pack(">H", Z)
>>> Block[0:16]
'\x00\x01\x00\x00\x00\x02\x00\x00\x03\x00\x00\x00\x00\x04\x00\x00'
>>>
You might also want to consider Construct
http://construct.wikispaces.com/
>From the web page: Construct is a python library for parsing and
building of data structures (binary or textual). It is based on the
concept of defining data structures in a declarative manner, rather
than procedural code: more complex constructs are composed of a
hierarchy of simpler ones. It's the first library that makes parsing
fun, instead of the usual headache it is today.
--
Nick Craig-Wood <[EMAIL PROTECTED]> -- http://www.craig-wood.com/nick
--
http://mail.python.org/mailman/listinfo/python-list
