That worked, I tried it with string elements also
Thanks a bunch --- On Sun, 12/7/08, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> > Subject: Tutor Digest, Vol 58, Issue 22 > To: tutor@python.org > Date: Sunday, December 7, 2008, 6:00 AM > Send Tutor mailing list submissions to > tutor@python.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://mail.python.org/mailman/listinfo/tutor > or, via email, send a message with subject or body > 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more > specific > than "Re: Contents of Tutor digest..." > > > Today's Topics: > > 1. Re: Newbie Wondering About Threads (Lie Ryan) > 2. Re: Sorting on different fields (Lie Ryan) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 7 Dec 2008 07:58:11 +0000 (UTC) > From: Lie Ryan <[EMAIL PROTECTED]> > Subject: Re: [Tutor] Newbie Wondering About Threads > To: tutor@python.org > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=UTF-8 > > On Sat, 06 Dec 2008 21:43:11 -0500, Damon Timm wrote: > > > On Sat, Dec 6, 2008 at 6:25 PM, Python Nutter > <[EMAIL PROTECTED]> > > wrote: > >> I'm on my phone so excuse the simple reply. > From what I skimmed you are > >> wrapping shell commands which is what I do all the > time. Some hints. 1) > >> look into popen or subprocess in place of execute > for more flexibility. > >> I use popen a lot and assigning a popen call to an > object name let's > >> you parse the output and make informed decisions > depending on what the > >> shell program outputs. > > > > So I took a peak at subprocess.Popen --> looks like > that's the direction > > I would be headed for parallel processes ... a real > simple way to see it > > work for me was: > > > > p2 = > subprocess.Popen(["lame","--silent","test.wav","test.mp3"]) > > > p3 = > subprocess.Popen(["lame","--silent","test2.wav","test2.mp3"]) > > > p2.wait() > > p3.wait() > > I think when you do that (p2.wait() then p3.wait() ), if p3 > finishes > first, you wouldn't start another p3 until p2 have > finished (i.e. until > p2.wait() returns) and if p2 finishes first, you > wouldn't start another > p2 until p3 finishes (i.e. until p3.wait() returns ). > > The solution would be to start and wait() the subprocessess > in two > threads. Use threading module or -- if you use python2.6 -- > the new > multiprocessing module. > > Alternatively, you could do a "non-blocking > wait", i.e. poll the thread. > > while True: > if p1.poll(): # start another p1 > if p2.poll(): # start another p2 > > > > > top showed that both cores get busy and it takes half > the time! So > > that's great -- when I tried to add the flac > decoding through stdout I > > was able to accomplish it as well ... I was mimicing > the command of > > "flac --decode --stdout test.flac | lame - > test.mp3" ... see: > > > > p = > subprocess.Popen(["flac","--decode","--stdout","test.flac"], > > stdout=subprocess.PIPE) > > p2 = > subprocess.Popen(["lame","-","test.mp3"], > stdin=subprocess.PIPE) > > p2.communicate(p.communicate()[0]) > > > > That did the trick - it worked! However, it was > *very* slow! The > > python script has a "real" time of 2m22.504s > whereas if I run it from > > the command line it is only 0m18.594s. Not sure why > this is ... > > > > The last piece of my puzzle though, I am having > trouble wrapping my head > > around ... I will have a list of files > > > ["file1.flac","file2.flac","file3.flac","etc"] > and I want the program to > > tackle compressing two at a time ... but not more than > two at a time (or > > four, or eight, or whatever) because that's not > going to help me at all > > (I have dual cores right now) ... I am having trouble > thinking how I can > > create the algorithm that would do this for me ... > > > > Thanks everyone. Maybe after a good night's sleep > it will come to me. > > If you have any ideas - would love to hear them. > > > > ------------------------------ > > Message: 2 > Date: Sun, 7 Dec 2008 10:31:11 +0000 (UTC) > From: Lie Ryan <[EMAIL PROTECTED]> > Subject: Re: [Tutor] Sorting on different fields > To: tutor@python.org > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=UTF-8 > > On Sat, 06 Dec 2008 21:47:16 -0800, the New me wrote: > > > is there a straightforward example? > > >>> import operator > >>> k = [[1, 2, 3, 4], [4, 3, 2, 1], [1, 3, 2, 4], > [2, 4, 3, 1]] > >>> sorted(l, key=operator.itemgetter(3, 2)) > [[4, 3, 2, 1], [2, 4, 3, 1], [1, 3, 2, 4], [1, 2, 3, 4]] > >>> for k in sorted(l, key=operator.itemgetter(0, > 2)): print k > ... > [1, 3, 2, 4] > [1, 2, 3, 4] > [2, 4, 3, 1] > [4, 3, 2, 1] > >>> def genkey(item): > ... return item[2] > ... > >>> for k in sorted(l, key=genkey): print k > ... > [4, 3, 2, 1] > [1, 3, 2, 4] > [1, 2, 3, 4] > [2, 4, 3, 1] > >>> def genkey(item): > ... return item[2], item[1] > ... > >>> for k in sorted(l, key=genkey): print k > ... > [4, 3, 2, 1] > [1, 3, 2, 4] > [1, 2, 3, 4] > [2, 4, 3, 1] > > > > ------------------------------ > > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > > > End of Tutor Digest, Vol 58, Issue 22 > ************************************* _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
