🌐 Mailman 3 May 2006 - Python-list - python.org

regd efficient methods to manipulate *large* files
by Madhusudhanan Chandrasekaran May 1, 2006

May 1, 2006

Hi: This question is not directed "entirely" at python only. But since I want to know how to do it in python, I am posting here. I am constructing a huge matrix (m x n), whose columns n are stored in smaller files. Once I read m such files, my matrix is complete. I want to pass this matrix as an input to another script of mine (I just have the binary.) Currently, the script reads a file (which is nothing but the matrix) and processes it. Is there any way of doing this in memory, without writing the matrix onto the disk? Since I have to repeat my experimentation for multiple iterations, it becomes expensive to write the matrix onto the disk. Thanks in advance. Help appreciated. -Madhu

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Re: python about mobile game?
by cyberco May 1, 2006

May 1, 2006

http://sourceforge.net/projects/pys60

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Difference between threading.local and protecting data with locks
by juxstapose May 1, 2006

May 1, 2006

Hello, I have been develop a blocking socket application with threading. The main thread handles connections and inserts them into python's protected queue as jobs for the thread pool to handle. There is not much information on threading.local except that it states that in maintains variable uniqueness among multiple instances of the same thread. I am assuming that it implements some sort of locking functionality under the covers? Is it possible to run into a race condition using threading.local? In a non-blocking threaded socket receive handler is it better to use a threading.local variable for writes or protect the write with a lock.acquire/lock.release ? I know the size of the incoming request so the receive handler finishes when the max size is reached. However in case of network problems I also have timeout functionality. Both of these behaviors require writing to variables in a possible critical section. What is the best way to handle writes in a multi-threaded non-blocking receive handler?

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Could not find platform independent libraries
by pythonhelpneeded May 1, 2006

May 1, 2006

While building Python 2.4.3 on SCO OpenServer 5.0.5, I'm getting the error below. The modules mentioned seem to be available in the Lib subdirectory. I've tried setting PYTHONHOME to the build directory (/tmp/Python-2.4.3), it didn't help. Any help would be appreciated. # make case $MAKEFLAGS in \ *-s*) CC='cc' LDSHARED='cc -Wl,-G,-Bexport' OPT='-DNDEBUG -O' ./python -E ./setup.py -q build;; \ *) CC='cc' LDSHARED='cc -Wl,-G,-Bexport' OPT='-DNDEBUG -O' ./python -E ./setup.py build;; \ esac Could not find platform independent libraries <prefix> Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] 'import site' failed; use -v for traceback Traceback (most recent call last): File "./setup.py", line 6, in ? import sys, os, getopt, imp, re ImportError: No module named os *** Error code 1 (bu21) UX:make: ERROR: fatal error.

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[ANN] markup.py 1.4 - bugfix
by Daniel Nogradi May 1, 2006

May 1, 2006

I'm terribly sorry but there was a crucial bug left in the 1.3 release announced today. Thanks to a user now it's fixed, and the new 1.4 release is available on http://markup.sourceforge.net/ which should be okay. Sorry for the inconvenience :)

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Re: How do I take a directory name from a given dir?
by Merrigan May 1, 2006

May 1, 2006

WOW, Thanks guys. I am really awestruck by the speed you guys relied with. Thanks a lot for the help. I eventually found a way that did the job for me. I will definitely visit this Group more often. Thanks for all the help! :D

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Re: stdin: processing characters
by Serge Orlov May 1, 2006

May 1, 2006

Kevin Simmons wrote: > Thanks for your input. I found an answer that suits my needs, not curses > :-), but stty settings and sys.stdin.read(n) : > > import os, sys > > while 1: > os.system("stty -icanon min 1 time 0") > print """ > Radio computer control program. > ------------------------------ > Choose a function: > po) Power toggle > fq) Change frequency > cm) Change mode > vo) Change volume > re) Reset > qu) Quit > -->""", > func = sys.stdin.read(2) > if func == "po": > ... > ... rest of menu actions ... > elif func = "qu": > os.system("stty cooked") > sys.exit() > Looks reasonable if you don't need portability. But you may want to refactor it a little bit to make sure terminal setting are always restored: try: do_all_the_work() finally: os.system("stty cooked") P.S. Maybe its me, but when I see call sys.exit() I always have a gut feeling this function never returns. But in fact my I'm wrong and sys.exit is more reasonable: it raises exception. So you can call sys.exit() inside do_all_the_work and you can still be sure that os.system("stty cooked") is always executed at the end.

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How do I take a directory name from a given dir?
by Merrigan May 1, 2006

May 1, 2006

Hi, I am trying to write a script to backup all my company's server configs weekly. The script will run in a cronjob, on whatever I set it. The issue I am currently having isto "extract" the directory name from a given directory string. For example: from the string "/home/testuser/projects/" I need to extract the "projects" part. The problem is that the directory names that needs to be used will never be the same lenght, so as far as my (very limited) knowledge stretches, slicing and indicing is out of the question. Can anybody help me, or give me an idea of what I should look at, seeing as I'm seriously stuck. I only started coding at the beginnig of the year, and was never interested before that, so my knowlege is basically non-existent. Thanks in advance for the help :)

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Re: How to efficiently read binary files?
by Grant Edwards May 1, 2006

May 1, 2006

On 2006-05-01, Robert Kern <robert.kern(a)gmail.com> wrote: > Oh, I saw the smiley. I knew it was meant to be humorous. I > just didn't understand it. The only "batteries" reference I > know of in this context is the "batteries included" philosophy > of the stdlib. Of course, none of Numeric, numarray, or numpy > have anything to do with the stdlib, so again I am confused. Sorry. I forgot about the distinction between the standard library and the "third-party" packages like scientific packages. -- Grant Edwards grante Yow! I think I'll make at SCRAMBLED EGGS!! They're visi.com each in LITTLE SHELLS...

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Re: How do I take a directory name from a given dir?
by Merrigan Took May 1, 2006

May 1, 2006

Daniel Nogradi wrote: >> Hi, >> >> I am trying to write a script to backup all my company's server configs >> weekly. The script will run in a cronjob, on whatever I set it. >> >> The issue I am currently having isto "extract" the directory name from >> a given directory string. For example: from the string >> "/home/testuser/projects/" I need to extract the "projects" part. The >> problem is that the directory names that needs to be used will never be >> the same lenght, so as far as my (very limited) knowledge stretches, >> slicing and indicing is out of the question. >> >> Can anybody help me, or give me an idea of what I should look at, >> seeing as I'm seriously stuck. I only started coding at the beginnig of >> the year, and was never interested before that, so my knowlege is >> basically non-existent. > > You can try this: > >>>> '/home/testuser/projects/'.strip( '/' ).split( '/' ) > ['home', 'testuser', 'projects'] > > strip gets rid of the first and last / and split splits the remaining > part and puts the results into a list. > > HTH :) AAAAh, ok, Thank you, I will definitely look into this and play with it!

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