How to represent a sequence of raw bytes

[bieffe62 at gmail.com]

On 22 Dic, 03:23, "Steven Woody" <narkewo... at gmail.com> wrote:
> Hi,
>
> What's the right type to represent a sequence of raw bytes.  In C, we usually do
>
> 1.  char buf[200]  or
> 2.  char buf[] = {0x11, 0x22, 0x33, ... }
>
> What's the equivalent representation for above in Python?
>
> Thanks.
>
> -
> narke

Usually, if I have to manipulate bytes (e.g. computing checksum,
etc...) i just use a list of numbers:

buf = [11, 22, 33, ...]

then when I need to put it in a buffer similar to the one in C (e.g.
before sending a packet of bytes through a socket
or another I/O channel), I use struct.pack

import struct
packed_buf = struct.pack('B'*len(buf), buf )

similarly, if I get a packet of bytes from an I/O channel and I need
to do operation on them as single bytes, I do:

buf = struct.unpack('B'*len(packed_buf), packed_buf )

Note that struct.pack and struct.unpack can trasform packed bytes in
other kind of data, too ...

There are other - maybe more efficient - way of handling bytes in
python programs, like using array as already suggested, but, up
to now, I never needed them in my python programs, which are not real-
time stuff, but sometime need to process steady flows of
data.

Ciao
----
FB