[Tutor] reading output from a c executable.

[spir]

Ravi Kondamuru a écrit :
> I am trying to read a binary log file to extract system counters. These
> counters will then be used to generate web-based graphs using the
> chart-director api in python. For extracting the counters I planning to
> write a program in C to read and give the output as lists for use by
> chart-director. If possible i would like to do the parsing of data only once
> in C on the log file and pass the processed output for direct use by
> python.
> I have thought about having to populate a database first but will prefer to
> avoid having another intermediate datastore (apart from the log file).
> 
> thanks,
> Ravi.
> 
> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com>wrote:
> 
>> Ravi Kondamuru wrote:
>>
>>> Hi,
>>> I am writing a script to read list output from a C executable. How should
>>> c program be written so that python can read the output as a list?
>>> Any pointers to info on this appreciated.
>>>
>> The possibilities are truly wide open on this.  Python can read a variety
>> of standard formats (and of course can have custom code to read anything.
>>  Depending on what the data involved actually are, you need to decide what
>> format works best.
>>
>> A simple approach is to have the C program write simple CSV output, and use
>> Python's csv module to read it.  A more complex solution might be to use
>> XML.  There are approximately 52,495,102 other possibilities available too,
>> so you have lots of room to work out what's best for your  application.
>>  More specific information on what you're trying to accomplish would help
>> narrow it down as well.

What type are these system counters? If you want to avoid reparsing in python, 
why not let C write a valid python literal, then simply import? (depends on 
what "huge" means for you). Assuming they are ints:
=========
counters.py:
counters = [
123,
456,
789,
...
]
=======
prog.py:
from counters import counters

denis