Comparison of parsers in python?

[Peng Yu]

On Sun, Sep 20, 2009 at 7:20 AM, andrew cooke <andrew at acooke.org> wrote:
> On Sep 20, 8:11 am, Peng Yu <pengyu... at gmail.com> wrote:
>> On Sun, Sep 20, 2009 at 6:50 AM, andrew cooke <and... at acooke.org> wrote:
>> > On Sep 19, 9:34 pm, Peng Yu <pengyu... at gmail.com> wrote:
>> >> On Sep 19, 6:05 pm, Robert Kern <robert.k... at gmail.com> wrote:
>> >> >http://nedbatchelder.com/text/python-parsers.html
>>
>> >> This is more a less just a list of parsers. I would like some detailed
>> >> guidelines on which one to choose for various parsing problems.
>>
>> > it would be simpler if you described what you want to do - parsers can
>> > be used for a lot of problems.
>>
>> I have never used any parser. The task at my hand right now is to
>> parse thishttp://genome.ucsc.edu/goldenPath/help/wiggle.html, which
>> is a fairly simple even without any parser package.
>>
>> I think that it is worthwhile for me to learn some parser packages to
>> try to parse this format. So that I may in future parse more complex
>> syntax. Do you have any suggestion what parser I should use for now?
>
> pyparsing would work fine for that, and has a broad community of users
> that will probably be helpful.
>
> i am currently working on an extension to lepl that is related, and i
> may use that format as an example.  if so, i'll tell you.  but for
> now, i think pyparsing makes more sense for you.

The file size of a wig file can be very large (GB). Most tasks on this
file format does not need the parser to save all the lines read from
the file in the memory to produce the parsing result. I'm wondering if
pyparsing is capable of parsing large wig files by keeping only
minimum required information in the memory.

Regards,
Peng