Pyparsing question

[Khoa Nguyen]

Hi,

I am a newbie to Python and pyparsing. I am having difficulty creating a
grammar that spans multiple lines, the input data look like this

RTSP/1.0 200 OK\r\n
Cseq: 1\r\n
Session: 12345-1\r\n
\r\n

Greatly appreciate if anyone can give me a sample or point me to the
right direction

Thanks,


Khoa Nguyen

[Paul McGuire]

Re: Pyparsing question

"Khoa Nguyen" <KNguyen@MEGIST O.com> wrote in message
news:mailman.13 .1084809534.694 9.python-list@python.org ...[color=blue]
> Hi,
>
> I am a newbie to Python and pyparsing. I am having difficulty creating a
> grammar that spans multiple lines, the input data look like this
>
> RTSP/1.0 200 OK\r\n
> Cseq: 1\r\n
> Session: 12345-1\r\n
> \r\n
>
> Greatly appreciate if anyone can give me a sample or point me to the
> right direction
>
> Thanks,
>
>
> Khoa Nguyen[/color]
=============== ==========
Khoa -

In general, pyparsing will ignore line breaks as whitespace. This data
could be parsed with as broad a grammar as:

response = Literal("RTSP") + restOfLine.setR esultsName("RTS Pline") + \
Literal("Cseq:" ) + restOfLine.setR esultsName("Cse qLine") + \
Literal("Sessio n:") + restOfLine.setR esultsName("Ses sionLine")

For more structure, enclose each line inside Group objects.
response = Group( Literal("RTSP") + restOfLine ).setResultsNam e("RTSPline")
+ \
Group( Literal("Cseq:" ) + restOfLine ).setResultsNam e("CseqLine") + \
Group( Literal("Sessio n:") + restOfLine ).setResultsNam e("SessionLine" )

Here is a working (and tested!) sample.

-- Paul


=============== ===========

from pyparsing import Literal, restOfLine, Group

data = """RTSP/1.0 200 OK
Cseq: 1
Session: 12345-1

"""

print "========"
print data
print "========"

response = Literal("RTSP") + restOfLine.setR esultsName("RTS Pline") + \
Literal("Cseq:" ) + restOfLine.setR esultsName("Cse qLine") + \
Literal("Sessio n:") + restOfLine.setR esultsName("Ses sionLine")

respFields = response.parseS tring(data)
print respFields
for k in respFields.keys ():
print k,"=",respField s[k]

=============== ============
Output:

========
RTSP/1.0 200 OK
Cseq: 1
Session: 12345-1


========
['RTSP', '/1.0 200 OK', 'Cseq:', ' 1', 'Session:', ' 12345-1']
SessionLine = 12345-1
RTSPline = /1.0 200 OK
CseqLine = 1
=============== =============
Output (using Group'ed constructs):
========
RTSP/1.0 200 OK
Cseq: 1
Session: 12345-1


========
[['RTSP', '/1.0 200 OK'], ['Cseq:', ' 1'], ['Session:', ' 12345-1']]
SessionLine = ['Session:', ' 12345-1']
RTSPline = ['RTSP', '/1.0 200 OK']
CseqLine = ['Cseq:', ' 1']