En Fri, 27 Feb 2009 10:10:39 -0200, MRAB <goo...@mrabarnett.plus.com>
escribió:
Gabriel Genellina wrote:
En Fri, 27 Feb 2009 09:29:16 -0200, Ulrich Eckhardt
<eckha...@satorlaser.com> escribió:
I have a socket from which I would like to parse some data, how would
I do
that? Of course, I can manually read data from the socket until
unpack()
stops complaining about a lack of data, but that sounds rather
inelegant.
Any better suggestions?
Read until you get the required bytes; use the size attribute.
The struct module has a function called "calcsize", eg:
>>> import struct
>>> struct.calcsize("<H")
2
That will tell you how many bytes to read.
The struct module defines also a Struct class; instead of using the module
functions, it's more efficient to create a Struct instance and call its
methods when one is going to use the same format more than once:
py> s = struct.Struct("<H")
py> s.size
2
py> s.unpack("\x40\x00")
(64,)
That's the size attribute I was talking about - too tersely perhaps.
--
Gabriel Genellina
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