Got it. Thank you Tim. Please look again at the latest trunk. My
implementation is much slower than yours but it is
independent of the database backend and I think this is a must.
If you can you optimize it further, that is very much welcome.
Massimo
On Dec 29, 11:02 am, mdipierro <mdipie...@cs.depaul.edu> wrote:
> Sorry. I must have got confused. I do not think I have seen your
> implementation than.
> Please email it to me.
>
> Massimo
>
> On Dec 29, 9:22 am, Timothy Farrell <tfarr...@swgen.com> wrote:
>
> > Yes, but before I do that, I want to clarify something.
> > My first implementation results in a JSON list of objects like so
> > (roughly):[ {field1:'field1val',field2:'field2val'},
> > {field1:'field1val',field2:'field2val'} ]
> > Your reimplementation results in a JSON list of lists where the first list
> > is the field (column) names like so:
> > [ ['field1', 'field2'], ['field1val', 'field2val'], ['field1val',
> > 'field2val'] ]
> > My implementation is more useful for programming in Javascript. With your
> > implementation (while more efficient on the wire), requires that we have to
> > unpack the data in client-side Javascript which adds an extra step for the
> > developer and, if the user has either IE and/or a slow computer this could
> > add an undesirable delay for large datasets (which was the whole point of
> > my using list comprehensions in the first place).
> > So can I send you a patch redone with my method (JSON list of objects)?
> > -tim
> > mdipierro wrote:where? Can you send me a patch? Massimo On Dec 29, 9:01 am,
> > Timothy Farrell<tfarr...@swgen.com>wrote:You might want to switch back to
> > list comprehensions. Granted the code is uglier but there are two big
> > reasons. 1) Speed. Seehttp://www.daniweb.com/forums/thread32869.htmlfor
> > more info. You could wrap the inner loop inner workings in a function and
> > still reap massive benefits by not having to call list.append() n^2 times.
> > 2) It's recommended for building lists in Py3k. The results of the above
> > linked test are:[0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30,
> > 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58] [0, 2, 4, 6, 8, 10,
> > 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48,
> > 50, 52, 54, 56, 58] Profile of evenList1(), check the time consumed by the
> > many append() calls: (ignore time consumed by the profiler itself) 50005
> > function calls in 0.174 CPU seconds Ordered by: standard name ncalls
> > tottime percall cumtime percall filename:lineno(function) 50000 0.066 0.000
> > 0.066 0.000 :0(append) 1 0.002 0.002 0.002 0.002 :0(range) 1 0.005 0.005
> > 0.005 0.005 :0(setprofile) 1 0.001 0.001 0.168 0.168 <string>:1(<module>) 1
> > 0.100 0.100 0.168 0.168 Script1.py:5(evenList1) 1 0.000 0.000 0.174 0.174
> > profile:0(evenList1()) 0 0.000 0.000 profile:0(profiler) Profile of
> > evenList2(): (ignore time consumed by the profiler itself) 5 function calls
> > in 0.018 CPU seconds Ordered by: standard name ncalls tottime percall
> > cumtime percall filename:lineno(function) 1 0.002 0.002 0.002 0.002
> > :0(range) 1 0.000 0.000 0.000 0.000 :0(setprofile) 1 0.001 0.001 0.018
> > 0.018 <string>:1(<module>) 1 0.015 0.015 0.017 0.017
> > Script1.py:15(evenList2) 1 0.000 0.000 0.018 0.018 profile:0(evenList2()) 0
> > 0.000 0.000 profile:0(profiler) mdipierro wrote:OK. it is in trunk but
> > slightly different. The representation is now independent on the database
> > backend. Massimo On Dec 29, 8:04 am, Timothy
> > Farrell<tfarr...@swgen.com>wrote:Massimo, would it help if I made a bzr
> > branch? Timothy Farrell wrote:I've been using this in my setup (my setup
> > has a few customizations) since the thread linked below. Just to say that
> > it works! -tim vince
> > wrote:http://groups.google.com/group/web2py/browse_thread/thread/8e3e33879974663f/64f76c562366aec4?lnk=gst&q=json#64f76c562366aec4willitbe
> > added or we'll have to wait? i think it's hard to avoid all dependency
> > contrib / thirdparty package. as long as it's include i think that's fine.
> > -vince-- Timothy Farrell<tfarr...@swgen.com>Computer Guy Statewide General
> > Insurance Agency (www.swgen.com)-- Timothy
> > Farrell<tfarr...@swgen.com>Computer Guy Statewide General Insurance Agency
> > (www.swgen.com)-- Timothy Farrell<tfarr...@swgen.com>Computer Guy Statewide
> > General Insurance Agency (www.swgen.com)-- Timothy
> > Farrell<tfarr...@swgen.com>Computer Guy Statewide General Insurance Agency
> > (www.swgen.com)
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