[Tutor] packet parsing

[dman]

On Thu, Feb 28, 2002 at 10:34:49PM +0100, Remco Gerlich wrote:
| On  0, python@jayed.com wrote:
 
| > OK, that makes sense.  But how do I peel of individual bytes?  (I just
| > played with lstrip and am not having any luck -- but this is probably my
| > lack of knowledge).
| 
| kexrecv[0] is the first byte, kexrecv[1] the second, etc.
| 
| Try
| 
| for byte ik kexrecv:
|    print ord(byte)
|    
| To see the integer values.

In addition, look at the 'struct' module.  It contains methods to
treat strings as packed binary data.  For example,

# turn my PyInt object into a bitstream :
s = struct.pack( "> i " , 13 )

# turn the bitsequence into a PyInt so I can perform mathmatical
# operations on it :
i = struct.unpack( "> i " , "\x00\x00\x00\x0d" )[ 0 ]

(note that in this example, s will have the value that is passed to
unpack() as a literal)

Try it out!  :-).  And read the docs too.

-D

-- 

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Word has no place in our lives.
        I John 1:10