Re: Question regarding __new__
En Thu, 22 Mar 2007 13:19:52 -0300, Frank Benkstein <[EMAIL PROTECTED]> escribió: > Yet [1] says: "[...] some rules for __new__: [...] If you return an > object of a different class, its __init__ method will be called." That was true at that time (2.2 initial), but not now. See http://www.python.org/sf/537450 Revision 26220 - Modified Sat Apr 6 01:05:01 2002 UTC (4 years, 11 months ago) by gvanrossum - Changed new-style class instantiation so that when C's __new__ method returns something that's not a C instance, its __init__ is not called. [SF bug #537450] The documentation should be updated to reflect this change. > Am I missing something? Is this documented somewhere else? See http://docs.python.org/ref/customization.html > Also it > would be nice if someone could point me to the function that implements > this in C. I didn't find anything in object.c or typeobject.c. It's in typeobject.c, function type_call -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with time
"Steve Holden" <[EMAIL PROTECTED]> a écrit dans le message de news: [EMAIL PROTECTED] > import time > import datetime > > dbtd = > h, m, s = time.localtime()[3:6] > timenow = s + (60 * (m + 60 * h)) Look like ok, thanks all :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiom for running compiled python scripts?
On Mar 23, 8:30 am, Mark <[EMAIL PROTECTED]> wrote: > > Of course I am not deleting the sources. In fact, I am also talking > about python scripts being called from shell scripts. There's a nice recipe in Python Cookbook (Martelli et al.) for this. It involves zipping your .pyc files and adding a shell stub. Never used it before but I'm going to need something similar in the near future, probably with a text templating system such as Cheetah (www.cheetahtemplate.org). HTH Gerard -- http://mail.python.org/mailman/listinfo/python-list
Re: How to receive a FILE* from Python under MinGW?
En Fri, 23 Mar 2007 01:47:22 -0300, John Pye <[EMAIL PROTECTED]> escribió: > On Mar 23, 3:33 pm, "Gabriel Genellina" <[EMAIL PROTECTED]> > wrote: >> import msvcrt >> fh = msvcrt.get_osfhandle(f.fileno()) > .. >> example.filetest(fh) >> f.close() > > Cool, that looks great, Gabriel. > > But is there any way I can hide the get_osfhandle call inside my > Python module? That way I wouldn't need to request end users to make > contorted 'if platform.system()=="Windows"' calls everywhere. > > Maybe this *is* workable, after all :-) I can think of two ways: - Define a Python function to do that, and test the platform just there. Something like that: def exportable_file(f): if we_are_working_on_windows: import msvcrt return msvcrt.get_osfhandle(f.fileno()) else: return f And replace all places where a Python file goes into a C extension, with exportable_file(f) - Define your own file class, inheriting from file, and store that handle as an attribute class my_file_class(file): def __init__(self, name, mode="r", buffering=-1): file.__init__(self, name, mode, buffering) self.handle = msvcrt.get_osfhandle(self.fileno()) But I've not checked this; I'm not sure if file creation always goes thru this __init__; I assume the file will never change its FILE struct (f_fp member) (uhm, is there any way to re-open a file?). Perhaps this approach has many assumptions to be usable at all - uh, forget it. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: python on window
En Fri, 23 Mar 2007 04:25:52 -0300, sandeep patil <[EMAIL PROTECTED]>
escribió:
> i have install python on window xp os.
> C:/program files/python
>
> i have done print program it working but .py can't working
> help me to how i will execute this file this file where i will save
> it.
> path execution how .
> tell me about any envorment veriable in python to set before python
> editor run,it path. etc
You don't need to set any environment variable to run Python. (Perhaps
PYTHONPATH, but *only* if you put modules into non standard places)
import posix
>
> Traceback (most recent call last):
> File "", line 1, in
> import posix
> ImportError: No module named posix
That's ok: there is no module named "posix" on Windows, it is only
available on Unix systems.
I've rearranged a bit your example. Write the following into a file named
test.py - use whatever editor you like (even notepad):
---begin file test.py---
def invert(table):
index = {}
for key in table:
value = table[key]
if not index.has_key(value):
index[value] = []
index[value].append(key)
return index
phonebook = {'sandeep':9325, 'amit':9822, 'anand':9890, 'titu': 9325}
print "Phonebook", phonebook
inverted_phonebook = invert(phonebook)
print "Inverted phonebook", inverted_phonebook
---end file test.py---
Then open a console window, change to the same directory where you saved
test.py, and execute:
python test.py
You should get:
Phonebook {'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
Inverted phonebook {9890: ['anand'], 9325: ['titu', 'sandeep'], 9822:
['amit']}
There are plenty of tutorials about Python. A good book -among others- is
"Dive into Python"; you can buy the book, read it online, or even download
it from http://www.diveintopython.org/
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Re: Making a non-root daemon process
On Mar 22, 11:19 pm, Ben Finney <[EMAIL PROTECTED]> wrote: > Howdy all, > > For making a Python program calve off an independent daemon process of > itself, I found Carl J. Schroeder's recipe in the ASPN Python Cookbook. > http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731> > > This is a thorough approach, and I'm cribbing a simpler process from > this example. One thing that strikes me is that the algorithm seems to > depend on running the program as the root user. > > import os > > def become_daemon(): > pid = os.fork() > if pid == 0: > # This is the child of the fork > > # Become a process leader of a new process group > os.setsid() > > # Fork again and exit this parent > pid = os.fork() > if pid == 0: > # This is the child of the second fork -- the running process. > pass > else: > # This is the parent of the second fork > # Exit to prevent zombie process > os._exit(0) > else: > # This is the parent of the fork > os._exit(0) > > become_daemon() > # Continue with the program > > The double-fork seems to be to: > - Allow the first forked child to start a new process group > - Allow the second forked child to be orphaned immediately > > The problem I'm having is that 'os.setsid()' fails with 'OSError: > [Errno 1] Operation not permitted' unless I run the program as the > root user. This isn't a program that I want necessarily running as > root. It works for me. I mean your program above produces no exceptions for me on Debian 3.1 python2.4 > What does the 'os.setsid()' gain me? It dettaches you from terminal. It means you won't receive signals from terminal for sure. Like SIGINT and SIGHUP, but there are maybe other. > How can I get that without being > the root user? Maybe you can go over the list of all possible signals from the terminal and notify kernel that you want to ignore them. Sounds similar to dettaching from the terminal, but maybe there some differences. But the fact that os.setsid fails for you is weird anyway. -- Leo. -- http://mail.python.org/mailman/listinfo/python-list
Re: how can I invoke a Java code?
momobear a écrit : > A friend of my write a Java program, and I want use it in my python > program as a module. I searched the topic in Google and find maybe the > better way is use GCJ to compile it. Is there any other way for me? > the simple and speediness choice the better. thanks. See my links: http://www.limsi.fr/Individu/pointal/python.html#liens-intautlang-java You can look at * Jython * JPype * JEP * java2python -- http://mail.python.org/mailman/listinfo/python-list
Re: python on window
On Mar 23, 7:25 am, "sandeep patil" <[EMAIL PROTECTED]> wrote:
> i have install python on window xp os.
> C:/program files/python
>
> i have done print program it working but .py can't working
> help me to how i will execute this file this file where i will save
> it.
> path execution how .
> tell me about any envorment veriable in python to set before python
> editor run,it path. etc
>
>
> >>> print ' sandeep patil'
> sandeep patil
> >>> print ' sandeep "bhagwan " patil ,msc. java j2ee developer"
>
> SyntaxError: EOL while scanning single-quoted string>>> print ' sandeep
> "bhagwan " patil ,msc. java j2ee developer'
>
> sandeep "bhagwan " patil ,msc. java j2ee developer
>
> >>> import posix
>
> Traceback (most recent call last):
> File "", line 1, in
> import posix
> ImportError: No module named posix
>
> >>> phonebook = {'sandeep':9325,'amit':9822,'anand':9890}
> >>> phonebook = {'titu':9423,'dadu':9422,'giri':9326}
> >>> inverted_phonebook=invert(phonebook)
>
> Traceback (most recent call last):
> File "", line 1, in
> inverted_phonebook=invert(phonebook)
> NameError: name 'invert' is not defined>>> def invert(table):
>
> index={}
> for key in table.key():
> value=table[key]
> if not index.has_key(value):
> index[value]=[]
> index[value].append(key)
> return index
>
Hi Sandeep.
As you are working with Python on Windows, I would suggest that you
install the Python for Windows extensions from here:
http://sourceforge.net/project/showfiles.php?group_id=78018
It includes a very good application called PythonWin. Once installed,
PythonWin will be available under Python in your Start menu.
If you run PythonWin, File/New gives you the option to create a new
Python script. To begin with, you can save into the Lib folder of your
Python installation (probably C:\Python25\Lib). I usually add my
initials at the front of the script name to differentiate my scripts
from the standard ones if I put stuff in Lib.
You should be able edit your PYTHONPATH variable in PythonWin - see
the Tools options (though, now I look, my installation actually has a
bug in this function), or alternatively, you can add a folder to your
PYTHONPATH environment variable in RegEdit (if you know what you're
doing).
I hope this helps.
J.
--
http://mail.python.org/mailman/listinfo/python-list
Re: python on window
That should have been: "You should be able edit your PYTHONPATH variable (should you need to)..." Gabiel is right, it's not usually required. -- http://mail.python.org/mailman/listinfo/python-list
Re: Making a non-root daemon process
"Leo Kislov" <[EMAIL PROTECTED]> writes: > On Mar 22, 11:19 pm, Ben Finney <[EMAIL PROTECTED]> wrote: > > The problem I'm having is that 'os.setsid()' fails with 'OSError: > > [Errno 1] Operation not permitted' unless I run the program as the > > root user. This isn't a program that I want necessarily running as > > root. > > It works for me. I mean your program above produces no exceptions > for me on Debian 3.1 python2.4 Hmm. I typed the example program in as a simplified version of what I'm doing; but didn't actually *run* it. When I do run it, I get no exception, as you say. Now I'll have to find out what significant difference there is between my failing code and this example, and report back in this thread. Thanks for showing me this far :-) -- \"Some people, when confronted with a problem, think 'I know, | `\ I'll use regular expressions'. Now they have two problems." -- | _o__)Jamie Zawinski, in alt.religion.emacs | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: how can I invoke a Java code?
momobear napisał(a): > A friend of my write a Java program, and I want use it in my python > program as a module. I searched the topic in Google and find maybe the > better way is use GCJ to compile it. Is there any other way for me? > the simple and speediness choice the better. thanks. If the speed is crucial, I suggest compiling the Java code with GCJ, then write Python extension module for the Java library. This is how the Lucene indexing library is ported to Python, see http://pylucene.osafoundation.org/. -- Jarek Zgoda "We read Knuth so you don't have to." -- http://mail.python.org/mailman/listinfo/python-list
$1 download the newest pda software
Want access to 15000+ all the new pda applications? just $1 register for one account to download/buy applications in this site. http://handpedia.vicp.cc/ this is one-time email, thank your reading. -- http://mail.python.org/mailman/listinfo/python-list
Create new processes over telnet in XP
Hello, How do you create/spawn new processes in XP over telnet using python? I.e. I would like to create a new process and have it running in the background... when I terminate the telnet connection, I would what the spawned processes to keep running until I shut it off... I got the os.popen method to spawn a new process running in the backgroun, but not over telnet... tried os.popen[2, 3, 4] and also subprocesses.popen without any luck... Any help will be appreciated... thankyou. -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to learn Python
Hi! PythonBiter wrote: > I'm very new in this Group as well Python language. I want to learn > Python. So could you please advice me, and guide me how can i become > master in Python ! If you are new to programming in general, too, the "Non-Programmer's Tutorial for Python" is a good start: http://en.wikibooks.org/wiki/Non-Programmer%27s_Tutorial_for_Python Cheers, Ben -- http://mail.python.org/mailman/listinfo/python-list
Re: Making GIF image twice the size - in memory
Miki wrote:
> Hello All,
>
Heelo,
> I get an image from a web page (via urlopen), and like to make it
> twice the size.
<-cut->
> However I don't get a valid GIF image.
>
Your code work well here!
Why you said that the string are invalid?
--code: test_image_double.py
from urllib import urlopen
import Image
from ImageFile import Parser
def double(image_data):
image_parser = Parser()
image_parser.feed(image_data)
im = image_parser.close()
new_size = tuple(map(lambda x: 2 * x, im.size))
new = im.resize(new_size)
return new.tostring("gif", "P"), new, new_size
url = "http://www.google.com/intl/en_ALL/images/logo.gif";
image_data = urlopen(url).read()
image_data, img, new_size = double(image_data)
img_new = Image.fromstring("P", new_size, image_data, "gif")
img_new.save("./out1.gif")
img.save("./out2.gif")
print "PIL version:", Image.VERSION
-- test
michele:~/tmp$ python test_image_double.py && file out1.gif && file out2.gif
(552, 220) 49554
PIL version: 1.1.5
out1.gif: GIF image data, version 87a, 552 x 220
out2.gif: GIF image data, version 87a, 552 x 220
michele:~/tmp$
> Any ideas?
>
Forgot to specify that the data aren't in raw format, but to decode it
with the "gif" encoder?
> Thanks,
Ciao,
Michele
--
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"finally" for unit test
hi! I have a unittest framework that tests a single function that in turn works with files (takes input and outputs in the same file, no return values). In the unittest class I assign a member with all the names of my testfiles and a testdirectory. The tests call the function (which opens and writes to the file) and then opens the file to see if everything is in order. The problem now is that after each testrun I have to copy "fresh" files into the testdirectory, since of course the function already run on all the files and made the changes. So I implemented a buffering in the unittest functions: buffer the file, call the function, make the test, write the buffered file back. This works fine for unittests that do not fail. If a unittest fails though the function stops and the writing back is never done. Is there something like a finally for unittest functions? Or could I use another approach to buffer and write back my files (for each unittest function)? thanks! gabriel -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiom for running compiled python scripts?
On Fri, 23 Mar 2007 07:30:58 +, Mark wrote:
> On Fri, 23 Mar 2007 14:03:12 +1100, Steven D'Aprano wrote:
>> Since you've done these tests already, perhaps you can tell us what gain
>> you actually got?
>
> About the same as you, ~20 msecs for my small script samples.
Well, I think that pretty much answers your question about whether it is
worth pre-compiling short shell scripts: you save about 20ms in execution
time, and lose 200ms in typing time. (Maybe a bit less if you are a
fast typist and don't use auto-completion.) You do the maths.
>> Of course you have to type the "c". You're not deleting the source files
>> away are you? *wink*
>
> Sorry, the wink is lost on me?
It is because I didn't really think you were deleting the source files.
That would be incredibly stupid. But I mentioned it just in case some
not-so-bright spark decided to argue that you could use auto-completion
without needing to type that final "c" if you deleted the source file.
Presumably now somebody is going to suggest merely *moving* the source
files into another directory, thus spending a minute or two each time they
edit a script re-arranging files in order to save twenty or thirty
milliseconds when they execute the script. Hey, if your time is so
valuable that 20ms means that much to you, go for it.
> Of course I am not deleting the sources. In fact, I am also talking
> about python scripts being called from shell scripts. I guess I'm just
> surprised that the python installation does not provide a small stub
> invoker, e.g:
>
> A small script called "python_compile_and_run" in "pseudo" code:
[snip pseudo-code]
> so I could just do a "python_compile_and_run myscript.py" and it would
> do what I want, i.e. run myscript.pyc if available and valid, generate
> and run it if necessary.
You shouldn't expect Python to come with every imaginable special-purpose
script already written for you! Besides, it's pretty simple to get that
functionality by hand when you need it, or automatically for that matter.
Here's one (untested) script that executes the pyc file in a subshell if
it exists and is new enough, and compiles it if it doesn't.
import os, sys, compiler
from stat import ST_MTIME as MT
if __name__ == "__main__":
scriptname = sys.argv[1]
compiledname = scriptname + "c"
if not os.path.exists(compiledname) or \
os.stat(compiledname)[MT] < os.stat(scriptname)[MT]:
# compiled file doesn't exist, or is too old
compiler.compileFile(scriptname)
assert os.path.exists(compiledname)
resultcode = os.system('python %s' % compiledname)
sys.exit(resultcode)
Now don't forget to test whether launching the subshell takes longer than
the 20ms you might save. All that effort, and wouldn't it be ironic if it
was actually *slower* than executing the script from scratch each time...
--
Steven.
--
http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
On Fri, 23 Mar 2007 04:18:59 -0700, killkolor wrote: > The problem now is that after each testrun I have to copy "fresh" files > into the testdirectory, since of course the function already run on all > the files and made the changes. So I implemented a buffering in the > unittest functions: buffer the file, call the function, make the test, > write the buffered file back. This works fine for unittests that do not > fail. If a unittest fails though the function stops and the writing back > is never done. Is there something like a finally for unittest functions? > Or could I use another approach to buffer and write back my files (for > each unittest function)? A simple approach would be to copy the test files *before* running the tests, instead of after. That way it doesn't matter if the tests fail or not: the next run will simply replace the test files with known good copies, regardless. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Been a while...
On 22 Mar, 16:34, John Salerno <[EMAIL PROTECTED]> wrote: > Hi guys. It's been a while since I've used Python, so I got a little > rusty, but I really want to start using it again, just out of habit and > for fun. Can anyone suggest a book or a website with little projects I > could work on to keep me busy? The Python Wiki's Beginner's Guide is one place to start: http://wiki.python.org/moin/BeginnersGuide > (I do have Beginning Python with the 10 projects in the back, but those > might be a little too involved for me right now.) There are many ideas for projects on the Wiki, too: http://wiki.python.org/moin/CodingProjectIdeas I think a lot of them might be quite difficult for beginners, however. Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
You could use pexpect module. Open a telnet session Then run the script in nohup mode It's assumed that the binary is available over there On 23 Mar 2007 03:47:14 -0700, Godzilla <[EMAIL PROTECTED]> wrote: Hello, How do you create/spawn new processes in XP over telnet using python? I.e. I would like to create a new process and have it running in the background... when I terminate the telnet connection, I would what the spawned processes to keep running until I shut it off... I got the os.popen method to spawn a new process running in the backgroun, but not over telnet... tried os.popen[2, 3, 4] and also subprocesses.popen without any luck... Any help will be appreciated... thankyou. -- http://mail.python.org/mailman/listinfo/python-list -- Regards-- Rishi Pathak National PARAM Supercomputing Facility Center for Development of Advanced Computing(C-DAC) Pune University Campus,Ganesh Khind Road Pune-Maharastra -- http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
killkolor wrote: > I have a unittest framework that tests a single function that in turn > works with files (takes input and outputs in the same file, no return > values). > In the unittest class I assign a member with all the names of my > testfiles and a testdirectory. The tests call the function (which > opens and writes to the file) and then opens the file to see if > everything is in order. The problem now is that after each testrun I > have to copy "fresh" files into the testdirectory, since of course the > function already run on all the files and made the changes. So I > implemented a buffering in the unittest functions: buffer the file, > call the function, make the test, write the buffered file back. This > works fine for unittests that do not fail. If a unittest fails though > the function stops and the writing back is never done. Is there > something like a finally for unittest functions? TestCase.tearDown() http://docs.python.org/lib/testcase-objects.html#l2h-5002 > Or could I use > another approach to buffer and write back my files (for each unittest > function)? Rather than restoring the file I would just delete it and use TestCase.setUp() to make a fresh copy. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Help controlling CDROM from python
If you want an OS neutral way one may be able to use pycdio from the
Cheese shop.
It requires libcdio to be installed and that sometimes the case if you
have a free media player (like vlc or xine, or mplayer) installed.
I don't really use it all that often so I can't vouch for how good it
is. (Although there *are* regression tests).
Ognjen Bezanov <[EMAIL PROTECTED]> writes:
> Hello,
>
> I am trying to control a CD-ROM drive using python. The code I use is
> shown below.
>
> > import CDROM
> > from fcntl import ioctl
> > import os
> >
> >
> > class Device:
> >
> > CDdevice=""
> > CDfd = None
> >
> > def __init__(self,name):
> > self.CDdevice = name#we get a device name when module loaded
> >
> > if self.CDdevice == "":
> > print "No device specified"
> > sys.exit(-1)
> > self.openCD()
> >
> > def openCD(self):
> >
> > try:
> > self.CDfd = open(self.CDdevice, 'r') #open the device
> > and return filedescriptor
> >
> > except(OSError,IOError): #if there is an OS or IO Error
> > (usually indicates nodisk)
> > print "Device Error, Halting (usually means drive
> > or disk not found)"
> > sys.exit(-1)
>
> > def unlockCD(self):
> > return self.sendCDcommand(CDROM.CDROM_LOCKDOOR,0)
>
> > def ejectCD(self):
> > self.unlockCD() #we need to unlock the CD tray before we try to
> > eject, otherwise we get an IO Error (#5)
> > return self.sendCDcommand(CDROM.CDROMEJECT)
> >
>
>
> > def sendCDcommand(self,command,argument=''):
> > return ioctl(self.CDfd,command,argument)
> >
>
>
>
> The code that calls the class is a follows:
>
> > import CD_Bindings
> >
> > CD = CD_Bindings.Device("/dev/cdrom")
> >
> > print CD.ejectCD()
>
> This works great, but only when there is a disk inside, otherwise we get
> an error.
>
> My issue is that I need to be able to eject the CDROM tray even if there
> is no disk inside.
>
> This is possible because other programs (like the linux "eject" command)
> can do it. Its just a question of how it is done in python. So I'm
> posting here in the hope someone can tell me.
>
> Thanks,
>
> Ognjen
--
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Re: "finally" for unit test
"killkolor" <[EMAIL PROTECTED]> wrote: > I have a unittest framework that tests a single function that in turn > works with files (takes input and outputs in the same file, no return > values). I would want to split that function into two: a) one which does the processing, but not working with a file, b) and one which handles reading and calls the processing function and then writes the file. The function it calls would be passed in as an optional parameter and defaults to function (a) Then you need two sets of tests: one to test the action of reading data from a file and then rewriting the output in-place, but you just pass in a mock function for the processing which can assert that it saw the expected inputs. and as many tests as you want for the processing, but no annoying files to get in the way. If you really cannot have the processing without reading from a file, then let it take two files, input and output as parameters, and have the (b) function choose between calling it with separate input/output files or creating a temporary file which is renamed to replace the original on completion. Then at least you can read directly from the test inputs without ever needing to write them. -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiom for running compiled python scripts?
On Fri, 23 Mar 2007 22:24:07 +1100, Steven D'Aprano wrote: > if not os.path.exists(compiledname) or \ os.stat(compiledname)[MT] < > os.stat(scriptname)[MT]: > # compiled file doesn't exist, or is too old Surely the validity check done by Python is more sophisticated than this? Doesn't the binary file have to be compiled under the same python version etc? > Now don't forget to test whether launching the subshell takes longer > than the 20ms you might save. All that effort, and wouldn't it be ironic > if it was actually *slower* than executing the script from scratch each > time... But Python proper is executing all the above anyhow isn't it? So the 20 msecs advantage I measured already includes this logic. Anyhow, I give up. Compilation, it seems, only applies to python modules. Compilation is not appropriate for Python scripts. Should be in the FAQ. -- http://mail.python.org/mailman/listinfo/python-list
Cleanly exiting multi thread application on SIGINT
Is the following the most elegant way to exit a multi-threaded application on a Ctrl-C? I am a complete beginner and would have thought there was some way of doing it without having to use while 1: pass, but have yet to find a way. N.B. exit() is a method for cleanly exiting the thread using a queue. Many thanks Jon def main: wt = workerThread() wt.setDaemon(True) wt.start() ct = counterThread() ct.setDaemon(True) ct.start() try: while 1: pass except KeyboardInterrupt: wt.exit() ct.exit() -- http://mail.python.org/mailman/listinfo/python-list
Re: On Java's Interface (the meaning of interface in computer programing)
Sherm Pendley wrote: > Lew <[EMAIL PROTECTED]> writes: > >> Jim Burton wrote: >>> Or you could stop feeding the trolls. >> Does not apply. The OP was not being trollish > > You obviously don't know Xah. He's been doing this for years, cross- > posting to various language groups trying to start an argument between > them. He even brags about being a troll on his web site. OK - that last is telling. I believe in the possibility of redemption: if a troll posts non-trollishly then I am willing to give them the benefit of the doubt. But if Xah were being trollish, why didn't they jump on my response and call me names? I still think that analysis of the original post is a useful exercise to learn Java. It's one thing to know what's right - it's another to know what's wrong and exactly why. The more subtle Xah or other minions of Satan get in their presentations, the more interesting the forensic exercise to dig out the truth. Perhaps I am just trying to make a silk purse out of a sow's ear. -- Lew -- http://mail.python.org/mailman/listinfo/python-list
Re: How to receive a FILE* from Python under MinGW?
On Mar 23, 7:48 pm, "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > > And replace all places where a Python file goes into a C extension, with > exportable_file(f) What about calling mscvrt_get_osfhandle from inside the SWIG wrapper? I tried this but it seemed that the function was not exported to the DLL. Cheers JP -- http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
I went with the TestCase.setUp() function. Thanks a lot! -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to learn Python
Online Docs, and Core Python Programming fits the bill! (http:// starship.python.net/crew/wesc/cpp/) -- http://mail.python.org/mailman/listinfo/python-list
Catching an unknown error
Using the code below:
---BEGIN CODE---
value = raw_input("Type a divisor: ")
try:
value = int(value)
print "42 / %d = %d" % (value, 42/value)
except ValueError:
print "I can't convert the value to an integer"
except ZeroDivisionError:
print "Your value should not be zero"
except:
print "Something unexpected happened"
---END CODE---
In the last 'except' block, how can I print out the particular error
name even though one is not specifically named?
Thanks,
Harlin
--
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Re: Need help to learn Python
On Mar 23, 12:03 am, "PythonBiter" <[EMAIL PROTECTED]> wrote: > Hi everyone, > > I'm very new in this Group as well Python language. I want to learn > Python. So could you please advice me, and guide me how can i become > master in Python ! > > Thanks, > Partha If you need books for a beginner in Python, go with "Python Programming for the Absolute Beginner" by Dawson, or "Python Programming: An Introduction to Computer Science" by Zelle. Core Python Programming is mostly theory and very little code. It's good for reference and digging deeper into the language, if you don't mind some screwy grammatical errors here and there. Programming Python 3rd Ed (by Lutz) has lots of code to dig into, but I would say it is for intermediate to advanced users. It also contains many practical useful scripts in it. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Catching an unknown error
On Mar 23, 8:16 am, "Harlin Seritt" <[EMAIL PROTECTED]> wrote:
> Using the code below:
>
> ---BEGIN CODE---
>
> value = raw_input("Type a divisor: ")
> try:
>value = int(value)
>print "42 / %d = %d" % (value, 42/value)
> except ValueError:
> print "I can't convert the value to an integer"
> except ZeroDivisionError:
> print "Your value should not be zero"
> except:
> print "Something unexpected happened"
>
> ---END CODE---
>
> In the last 'except' block, how can I print out the particular error
> name even though one is not specifically named?
>
> Thanks,
>
> Harlin
Make the last 'except' block like this:
Except Exception, e:
print e
Mike
--
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Re: Catching an unknown error
Harlin Seritt wrote: > In the last 'except' block, how can I print out the particular error > name even though one is not specifically named? the sys.exc_info() function returns information about the current exception. see: http://effbot.org/pyref/sys.exc_info -- http://mail.python.org/mailman/listinfo/python-list
Re: Catching an unknown error
On Mar 23, 8:29 am, [EMAIL PROTECTED] wrote:
> On Mar 23, 8:16 am, "Harlin Seritt" <[EMAIL PROTECTED]> wrote:
>
>
>
> > Using the code below:
>
> > ---BEGIN CODE---
>
> > value = raw_input("Type a divisor: ")
> > try:
> >value = int(value)
> >print "42 / %d = %d" % (value, 42/value)
> > except ValueError:
> > print "I can't convert the value to an integer"
> > except ZeroDivisionError:
> > print "Your value should not be zero"
> > except:
> > print "Something unexpected happened"
>
> > ---END CODE---
>
> > In the last 'except' block, how can I print out the particular error
> > name even though one is not specifically named?
>
> > Thanks,
>
> > Harlin
>
> Make the last 'except' block like this:
>
> Except Exception, e:
>print e
>
> Mike
just don't capitalize the word "except" ... my bad
--
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Re: Catching an unknown error
[EMAIL PROTECTED] wrote: > Make the last 'except' block like this: > > Except Exception, e: > print e while that's good enough for the given example, it's not good enough for the general case (in contemporary Python, exceptions don't have to inherit from the Exception class). -- http://mail.python.org/mailman/listinfo/python-list
Re: Cleanly exiting multi thread application on SIGINT
"jrpfinch" wrote: > Is the following the most elegant way to exit a multi-threaded > application on a Ctrl-C? I am a complete beginner and would have > thought there was some way of doing it without having to use while 1: > pass, but have yet to find a way. > def main: >wt = workerThread() >wt.setDaemon(True) >wt.start() >ct = counterThread() >ct.setDaemon(True) >ct.start() >try: >while 1: >pass you could at least insert a time.sleep(1), to avoid busy-looping. -- http://mail.python.org/mailman/listinfo/python-list
Re: Catching an unknown error
On Mar 23, 8:16 am, "Harlin Seritt" <[EMAIL PROTECTED]> wrote:
> Using the code below:
>
> ---BEGIN CODE---
>
> value = raw_input("Type a divisor: ")
> try:
>value = int(value)
>print "42 / %d = %d" % (value, 42/value)
> except ValueError:
> print "I can't convert the value to an integer"
> except ZeroDivisionError:
> print "Your value should not be zero"
> except:
> print "Something unexpected happened"
>
> ---END CODE---
>
> In the last 'except' block, how can I print out the particular error
> name even though one is not specifically named?
>
> Thanks,
>
> Harlin
Thanks for pointing that out. I was following logic I was taught in
Hetland's book, which supposedly was up-to-date for Python 2.4.
Typical textbook error.
Mike
--
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Re: Need help to learn Python
PythonBiter wrote: > Hi everyone, > > I'm very new in this Group as well Python language. I want to learn > Python. So could you please advice me, and guide me how can i become > master in Python ! > > > Thanks, > Partha > Lots of great resources for beginners: http://wiki.python.org/moin/BeginnersGuide/NonProgrammers -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiom for running compiled python scripts?
On Fri, 23 Mar 2007 12:22:44 +, mark wrote: > On Fri, 23 Mar 2007 22:24:07 +1100, Steven D'Aprano wrote: >> if not os.path.exists(compiledname) or \ os.stat(compiledname)[MT] < >> os.stat(scriptname)[MT]: >> # compiled file doesn't exist, or is too old > > Surely the validity check done by Python is more sophisticated than > this? Doesn't the binary file have to be compiled under the same python > version etc? Of course. What, do you want me to do all your work? :-) >> Now don't forget to test whether launching the subshell takes longer >> than the 20ms you might save. All that effort, and wouldn't it be ironic >> if it was actually *slower* than executing the script from scratch each >> time... > > But Python proper is executing all the above anyhow isn't it? So the 20 > msecs advantage I measured already includes this logic. I don't know how you measured the 20ms. When you call a script direct from the shell, you've already got a shell running. When you call a script from within Python via os.system, it has to launch a sub-shell. That takes time. > Anyhow, I give up. Compilation, it seems, only applies to python > modules. Compilation is not appropriate for Python scripts. Should be > in the FAQ. No, that's not true. Python scripts certainly take advantage of compiled modules. The real lesson of this is that optimization isn't necessarily straightforward. What we imagine "should be" faster might not be in practice -- especially when dealing with micro-optimizations that only save a few tens of milliseconds. Frankly, it simply isn't worth trying to save 20ms in a script that takes less than a second to run. If you scratch your nose before hitting enter, you've wasted a hundred times what you've just spent hours trying to save. Or, to put it another way: The Rules of Optimization are simple. Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. -- Michael A. Jackson (no, not that Michael Jackson), "Principles of Program Design", 1975. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Catching an unknown error
On Mar 23, 9:42 am, [EMAIL PROTECTED] wrote:
> On Mar 23, 8:16 am, "Harlin Seritt" <[EMAIL PROTECTED]> wrote:
>
>
>
> > Using the code below:
>
> > ---BEGIN CODE---
>
> > value = raw_input("Type a divisor: ")
> > try:
> >value = int(value)
> >print "42 / %d = %d" % (value, 42/value)
> > except ValueError:
> > print "I can't convert the value to an integer"
> > except ZeroDivisionError:
> > print "Your value should not be zero"
> > except:
> > print "Something unexpected happened"
>
> > ---END CODE---
>
> > In the last 'except' block, how can I print out the particular error
> > name even though one is not specifically named?
>
> > Thanks,
>
> > Harlin
>
> Thanks for pointing that out. I was following logic I was taught in
> Hetland's book, which supposedly was up-to-date for Python 2.4.
> Typical textbook error.
>
> Mike
Thanks guys... that gets 'er done.
Harlin Seritt
--
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Re: Create new processes over telnet in XP
Godzilla wrote:
> Hello,
>
> How do you create/spawn new processes in XP over telnet using python?
> I.e. I would like to create a new process and have it running in the
> background... when I terminate the telnet connection, I would what the
> spawned processes to keep running until I shut it off...
>
> I got the os.popen method to spawn a new process running in the
> backgroun, but not over telnet... tried os.popen[2, 3, 4] and also
> subprocesses.popen without any luck...
I don't know what kind of OS there is on that remote host you telnet
to.
The idea boils down to appropriate using of methods
`read_until` and `write` from class `telnetlib.Telnet`.
For more complicated stuff you can consider using pyexpect.
Here is a small example of connecting to HP-UX.
You can adjust that to your needs.
import telnetlib, time
def login(tn, login, passwd, prompt):
tn.read_until("login: ")
tn.write(login + "\n")
if passwd:
tn.read_until("Password: ")
tn.write(passwd + "\n")
tn.read_until(prompt)
time.sleep(2)
print "logged in"
def run_proc(tn, progname):
tn.write("nohup %s &\n" % progname)
tn.write("exit\n")
print "program <%s> running" % progname
def kill_proc(tn, login, prompt, progname):
tn.write("ps -u %s\n" % login)
buf = tn.read_until(prompt)
pid = get_pid(buf, progname)
if not pid:
print "program <%s> not killed" % progname
tn.write("exit\n")
return
tn.write("kill -TERM %s\n" % pid)
tn.write("exit\n")
print "program <%s> killed" % progname
def get_pid(buf, progname):
pid, comm = None, None
for line in buf.split("\n"):
try:
pid, _, _, comm = line.split()
except ValueError:
continue
if comm == progname:
return pid
tn = telnetlib.Telnet(HOST, PORT)
#tn.set_debuglevel(1)
login(tn, "login", "passwd", "/home/user")
run_proc(tn, "python ~/test.py")
#kill_proc(tn, "login", "/home/user", "python")
--
HTH,
Rob
--
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Re: "finally" for unit test
gabriel> Is there something like a finally for unittest functions? TestCase instances have setUp() and tearDown() methods: http://docs.python.org/dev/lib/testcase-objects.html Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: Catching an unknown error
Harlin> value = raw_input("Type a divisor: ")
Harlin> try:
Harlin>value = int(value)
Harlin>print "42 / %d = %d" % (value, 42/value)
Harlin> except ValueError:
Harlin> print "I can't convert the value to an integer"
Harlin> except ZeroDivisionError:
Harlin> print "Your value should not be zero"
Harlin> except:
Harlin> print "Something unexpected happened"
Harlin> In the last 'except' block, how can I print out the particular
Harlin> error name even though one is not specifically named?
>>> try:
... 1/0
... except Exception, err:
... print repr(err)
...
Skip
--
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Re: Cleanly exiting multi thread application on SIGINT
Jon> Is the following the most elegant way to exit a multi-threaded Jon> application on a Ctrl-C? I am a complete beginner and would have Jon> thought there was some way of doing it without having to use while Jon> 1: pass, but have yet to find a way. I thought there was some sort of wait() method in the threading module, but I was mistaken. Maybe: while threading.activeCount(): time.sleep(0.01) ? Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: Wikipedia and a little piece of Python History
On 21 Mar 2007 12:18:50 -0700, Paddy <[EMAIL PROTECTED]> wrote: > I just had a link to Tim peters first post on doctest: > http://groups.google.com/group/comp.lang.python/msg/1c57cfb7b3772763 > removed from http://en.wikipedia.org/wiki/Doctest as it doesn't fit > their guidelines for external links. > I wonder, could maybe the official website be persuaded to host a copy > so that it could be linked to? Wikipedia should have some guideline for referencing Usenet postings, somewhere ... Anyway, it's a good thing to provide at least the Message-ID of the posting. As an example, your your posting here was uniquely identified by the Message-ID <[EMAIL PROTECTED]> /Jorgen -- // Jorgen Grahn R'lyeh wgah'nagl fhtagn! -- http://mail.python.org/mailman/listinfo/python-list
Exception passing
Hi, I have a function, which looks like the following: connecting = False def func (): global connecting connecting = True try: # Do lot of network stuff except Exception, e: connecting = False raise e This works quite good, but it is a hell to debug. Instead of getting a log message to the line which originally raised the exception. Is there anyway to reraise an exception, but preserve the log? -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception passing
On Mar 23, 9:29 am, Thomas Dybdahl Ahle <[EMAIL PROTECTED]> wrote: > Hi, I have a function, which looks like the following: > > connecting = False > def func (): > global connecting > connecting = True > try: ># Do lot of network stuff > except Exception, e: > connecting = False > raise e > > This works quite good, but it is a hell to debug. Instead of getting a > log message to the line which originally raised the exception. > > Is there anyway to reraise an exception, but preserve the log? You could import traceback and use its functionality. Lundh mentioned using sys.exc_info about an hour ago to another user. See http://effbot.org/pyref/sys.exc_info.htm Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception passing
Thomas Dybdahl Ahle <[EMAIL PROTECTED]> wrote: > Hi, I have a function, which looks like the following: > > connecting = False > def func (): > global connecting > connecting = True > try: ># Do lot of network stuff > except Exception, e: > connecting = False > raise e > > This works quite good, but it is a hell to debug. Instead of getting a > log message to the line which originally raised the exception. > > Is there anyway to reraise an exception, but preserve the log? Just use raise without any argument. E.g.: >>> def raiser(): ... print 1/0 ... >>> def reraise1(): ... print 'before' ... try: raiser() ... except Exception, e: ... print 'after' ... raise e ... >>> def reraise2(): ... print 'before' ... try: raiser() ... except Exception, e: ... print 'after' ... raise ... >>> reraise1() before after Traceback (most recent call last): File "", line 1, in File "", line 6, in reraise1 ZeroDivisionError: integer division or modulo by zero >>> reraise2() before after Traceback (most recent call last): File "", line 1, in File "", line 3, in reraise2 File "", line 2, in raiser ZeroDivisionError: integer division or modulo by zero >>> As you see, the traceback is "maintained" when you just "raise", though it's altered when you "raise e". Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
On 23 Mar 2007 03:47:14 -0700, Godzilla <[EMAIL PROTECTED]> wrote: > Hello, > > How do you create/spawn new processes in XP over telnet using python? > I.e. I would like to create a new process and have it running in the > background... Ssh -- or even rsh -- are better choices than telnet for these things. For some reason, they are not standard in Windows, though. ssh somewhere some command with arguments rsh somewhere some command with arguments compared to telnet somewhere and then performing expect-like things (basically simulating someone typing "some command with arguments" in the telnet session). > when I terminate the telnet connection, I would what the > spawned processes to keep running until I shut it off... That's a function of the remote OS; what happens when its terminal goes away is not under the control of the client side. /Jorgen -- // Jorgen Grahn R'lyeh wgah'nagl fhtagn! -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiom for running compiled python scripts?
Mark <[EMAIL PROTECTED]> wrote: ... > so I could just do a "python_compile_and_run myscript.py" and it would > do what I want, i.e. run myscript.pyc if available and valid, generate > and run it if necessary. You can use python -c 'import myscript; myscript.main()' and variations thereon. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
On 23 Mar 2007 12:19:15 GMT, Duncan Booth <[EMAIL PROTECTED]> wrote: > "killkolor" <[EMAIL PROTECTED]> wrote: > >> I have a unittest framework that tests a single function that in turn >> works with files (takes input and outputs in the same file, no return >> values). > > I would want to split that function into two: > > a) one which does the processing, but not working with a file, Better to make it work with "a file", in the sense that it works with file-like objects so you can feed and leech it using StringIO. > b) and one which handles reading and calls the processing function and then > writes the file. The function it calls would be passed in as an optional > parameter and defaults to function (a) /Jorgen -- // Jorgen Grahn R'lyeh wgah'nagl fhtagn! -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception passing
Den Fri, 23 Mar 2007 07:38:47 -0700 skrev Alex Martelli: > Thomas Dybdahl Ahle <[EMAIL PROTECTED]> wrote: >> This works quite good, but it is a hell to debug. Instead of getting a >> log message to the line which originally raised the exception. > As you see, the traceback is "maintained" when you just "raise", though > it's altered when you "raise e". Thanks a lot :D -- http://mail.python.org/mailman/listinfo/python-list
Re: Mocking OpenOffice in python?
Méta-MCI schreef: > Hi! > > > Under windows, I drive OOo, from Python, via COM/OLE-automation. > > It's run OK, but some bugs, in the OOo-COM-Python, had stop my > devloppements... > > However, this way is usable (only on Win, ok?) > Do you have some (small) example program of using OOo from Python via COM/OLE? Can you give any indication of the kind of bugs that you hit? kind regards, Gerrit Muller Gaudi Systems Architecting -- http://mail.python.org/mailman/listinfo/python-list
Re: why brackets & commas in func calls can't be ommited? (maybe it could be PEP?)
On Thu, 22 Mar 2007 14:20:42 -0400, Steve Holden <[EMAIL PROTECTED]> wrote: ... > I'm in danger of getting short-tempered on c.l.py for the first time in > a long time. If you think that five arguments is an excessive number for > a function then you live in a world of toy programs. Or at least in a world where people have good taste and time to Do It Right(tm). I personally believe many five-argument methods would be better off refactored. I killed one today which had fourteen (most of which were unused). But I don't pretend that it's always worth the effort of doing that, in the real world. /Jorgen -- // Jorgen Grahn R'lyeh wgah'nagl fhtagn! -- http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
Jorgen Grahn <[EMAIL PROTECTED]> wrote: > On 23 Mar 2007 12:19:15 GMT, Duncan Booth > <[EMAIL PROTECTED]> wrote: >> "killkolor" <[EMAIL PROTECTED]> wrote: >> >>> I have a unittest framework that tests a single function that in >>> turn works with files (takes input and outputs in the same file, no >>> return values). >> >> I would want to split that function into two: >> >> a) one which does the processing, but not working with a file, > > Better to make it work with "a file", in the sense that it works with > file-like objects so you can feed and leech it using StringIO. I'm assuming, perhaps wrongly, that something which takes input from a file and produces output into the same file is doing something beyond the simple interface supported by StringIO. So I was guessing either that something like FileInput is involved, or seeking and modifying in-place. Anyway, the principle is the same: you make sure no function does more than one job, and you make sure that all functions are testable independently. -- http://mail.python.org/mailman/listinfo/python-list
How to list current line in pdb?
Hi all, Using the pdb shell, after repeatedly entering 'l' (lowercase 'L'), how do I jump back to listing the current line again if I don't remember exactly what line my current line is? Do I just have to list an early line in the code and repeatedly list from there until I see the '->' indicating the current line? Thanks, Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: fine grain logging cotrol
Peter Otten wrote: > Eric S. Johansson wrote: > > [in private mail -- please don't, Eric] sorry. my preference is for private mail. it's my way of trying to be kind to others by reducing list clutter. > I don't understand. The logging package detects the function name without > user intervention. not in 2.4 afaik. according to the docs for debug/info it the only kwargs which is inspected is exc_info. > Perhaps it's time to step back and explain what you want to achieve rather > than how you proceed. print a log message if a predicate yields true. should be able to have different predicates. the desired predicate is a match on class, method, and level number. class and method should be found automatically by the logging predicate code. apologies again for violating your email protocol and thanks for the help. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to list current line in pdb?
"Chris Lasher" <[EMAIL PROTECTED]> wrote: > Using the pdb shell, after repeatedly entering 'l' (lowercase 'L'), > how do I jump back to listing the current line again if I don't > remember exactly what line my current line is? Do I just have to list > an early line in the code and repeatedly list from there until I see > the '->' indicating the current line? Try: (Pdb) alias ll u;;d;;l and thereafter the 'll' command will list the current line (unless you are in the uppermost stack frame in which case it goes down one stackframe instead). Save the alias in your .pdbrc file. -- http://mail.python.org/mailman/listinfo/python-list
Re: GCC 4.1.2 installer for Python distutils compilation
On Mar 18, 6:22 pm, Giovanni Bajo <[EMAIL PROTECTED]> wrote: > On 18/03/2007 13.24, DavidRushbywrote: > > > Even though I have access to MSVC 7.1, so I don't really need MinGW > > myself, [...] > > But remember that GCC 4.1.2 is almost 4 years newer than MSVC 7.1, and > I found it to produce more optimized code (especially for C++). Since it's > a free alternative, it might be worth to give it a go :) I just wrote a high-performance Windows-1251 codec in C (an optimized alternative to Python's including 'cp1251' codec). On Windows 2000 / Prescott PIV, GCC 4.1.2 does indeed produce code that is 30% faster than MSVC (this is with aggressive optimization switch tinkering on both compilers). This is for fairly simple, non- floating-point C code. -- http://mail.python.org/mailman/listinfo/python-list
Re: Wikipedia and a little piece of Python History
Jorgen Grahn <[EMAIL PROTECTED]> writes: > Wikipedia should have some guideline for referencing Usenet postings, > somewhere ... It has one (WP:RS). The guideline is don't do it. The problem is that these guidelines arise out of disputes, i.e. maybe someone tried to use a Usenet post to prove something about a politician, and the result (reasonably) was a guideline that said Usenet posts weren't reliable sources of info. In the cases where it's something ok, the editors use common sense and leave it alone. Until that bot got loose and started removing all Usenet links whether they were ok or not. -- http://mail.python.org/mailman/listinfo/python-list
Re: Been a while...
"James Stroud" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hawk this list and try to pick off easy answers before anyone else. > That's what I do. The pressure is to be right, because if you're not, > you hear about it in a hurry. That is actually an excellent suggestion. Even if you can't answer a question, finding interesting and comprehanesible questions and then studying the various follow up posts is an excellent way to sharpen your Python skills, and broaden your knowledge about not only Python syntax and common pitfalls but about what modules are typically applied to various kinds of problems. -ej -- http://mail.python.org/mailman/listinfo/python-list
Multi-line strings with formatting
When constructing a particularly long and complicated command to be sent to the shell, I usually do something like this, to make the command as easy as possible to follow: commands.getoutput( 'mycommand -S %d -T %d ' % (s_switch, t_switch) + '-f1 %s -f2 %s ' % (filename1, filename2) + '> %s' % (log_filename) ) Can anyone suggest a better way to construct the command, especially without the "+" sign at the end of each line (except the last) ? If I take out the "+", then I need to move all the variables to the end, as so: commands.getoutput( 'mycommand -S %d -T %d ' '-f1 %s -f2 %s ' '> %s' % (s_switch, t_switch, filename1, filename2, log_filename) ) or: commands.getoutput( '''mycommand -S %d -T %d \ -f1 %s -f2 %s \ > %s''' % (s_switch, t_switch, filename1, filename2, log_filename) ) but having the variables line-by-line as in the first example is so much easier to edit, is it not? -- http://mail.python.org/mailman/listinfo/python-list
Re: Multi-line strings with formatting
On Fri, 2007-03-23 at 09:54 -0700, [EMAIL PROTECTED] wrote: > When constructing a particularly long and complicated command to be > sent to the shell, I usually do something like this, to make the > command as easy as possible to follow: > > commands.getoutput( > 'mycommand -S %d -T %d ' % (s_switch, t_switch) + > '-f1 %s -f2 %s ' % (filename1, filename2) + > '> %s' % (log_filename) > ) > > Can anyone suggest a better way to construct the command, especially > without the "+" sign at the end of each line (except the last) ? If I > take out the "+", then I need to move all the variables to the end, as > so: > > commands.getoutput( > 'mycommand -S %d -T %d ' > '-f1 %s -f2 %s ' > '> %s' > % (s_switch, t_switch, filename1, filename2, log_filename) > ) > > or: > > commands.getoutput( > '''mycommand -S %d -T %d \ > -f1 %s -f2 %s \ > > %s''' > % (s_switch, t_switch, filename1, filename2, log_filename) > ) You get the best of both worlds, i.e. one big multiline string with in-line parameters, by using a mapping: commands.getoutput( '''mycommand -S %(s_switch)d -T %(t_switch)d \ -f1 %(filename1)s -f2 %(filename2)s \ > %(log_filename)s''' % locals() ) Of course I'm assuming that s_switch etc. are local variables. If they're not, well, they ought to be. -Carsten -- http://mail.python.org/mailman/listinfo/python-list
detect suprocess interaction
I'm using subprocess to carry out svn commands (probably should use the svn api package, but that's a dependency too far). Anyhow my code looks like from subprocess import Popen, PIPE p = Popen((svn,'ls',u),stdout=PIPE,stderr=PIPE) i = p.wait() and this sort of thing works well under most circumstances. However, when this code is executed for the very first time by a particular user it hangs waiting on user input. This code is being used purely for testing correctness of a particular svn url so in the normal case we want to throw away both stdout and stderr. In the exceptional case is it possible to detect that input is required and only in that case issue the current contents of stdout (presumably a request for a password)? Clearly I need to supply some kind of input filelike object, but is this sort of thing possible. -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Compiler-AST-Walk-Visitor: Any Examples or Documentation?
Hello, I'm trying to write something that will translate Python code to pseudo-code (for teaching purposes). Googling around indicated that the compiler module is pertinent, especially creating a visitor to walk the generated AST: http://docs.python.org/lib/module-compiler.html I can build the AST, but I can't figure out how to write the visitor. The package documentation didn't help me out that much, and I couldn't find any examples. In fact, google only came up with this unanswered related question: http://mail.python.org/pipermail/python-list/2006-July/392716.html Any help is appreciated. Thanks and Bye, Efrat -- http://mail.python.org/mailman/listinfo/python-list
Re: fine grain logging cotrol
Eric S. Johansson wrote:
> Peter Otten wrote:
>> Eric S. Johansson wrote:
>>
>> [in private mail -- please don't, Eric]
>
> sorry. my preference is for private mail. it's my way of trying to be
> kind to others by reducing list clutter.
It is not list clutter in my book; it gives others the chance to correct,
add to, or even profit from our conversation.
>> I don't understand. The logging package detects the function name without
>> user intervention.
> not in 2.4 afaik.
Hmm, I must have overread that constraint in your previous posts...
Here is yet another revision of my example then:
import logging
import sys
class LoggedType(type):
def __new__(mcl, name, bases, classdict):
def get_logger(self):
return logging.getLogger("%s.%s" % (name,
sys._getframe(1).f_code.co_name))
classdict["_%s__logger" % name] = property(get_logger)
return type.__new__(mcl, name, bases, classdict)
class Logged:
__metaclass__ = LoggedType
class Felis(Logged):
def alpha(self):
self.__logger.info("Felis.alpha")
def gamma(self):
self.__logger.info("Felis.gamma")
class Catus(Felis):
def alpha(self):
self.__logger.info("Catus.alpha")
def beta(self):
self.__logger.info("Catus.beta")
if __name__ == "__main__":
logging.basicConfig(
format="EXPECTED %(message)s GOT %(name)s", level=logging.INFO)
f = Felis()
f.alpha()
f.gamma()
c = Catus()
c.alpha()
c.beta()
c.gamma()
Peter
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exit to interpreter?
Hi, I'm writing a function that polls the user for keyboard input, looping until it has determined that the user has entered a valid string of characters, in which case it returns that string so it can be processed up the call stack. My problem is this. I'd also like it to handle a special string (e.g. 'quit'), in which case control should return to the Python command line as opposed to returning the string up the call stack. sys.exit seemed like a good choice, but it exits the python interpreter. I could use an exception for this purpose, but was wondering if there's a better way? --b -- http://mail.python.org/mailman/listinfo/python-list
Re: How to list current line in pdb?
On Mar 23, 11:56 am, Duncan Booth <[EMAIL PROTECTED]> wrote: > "Chris Lasher" <[EMAIL PROTECTED]> wrote: > > Using the pdb shell, after repeatedly entering 'l' (lowercase 'L'), > > how do I jump back to listing the current line again if I don't > > remember exactly what line my current line is? Do I just have to list > > an early line in the code and repeatedly list from there until I see > > the '->' indicating the current line? > > Try: > > (Pdb) alias ll u;;d;;l > > and thereafter the 'll' command will list the current line (unless you are > in the uppermost stack frame in which case it goes down one stackframe > instead). > > Save the alias in your .pdbrc file. Alright. Thanks, Duncan! -- http://mail.python.org/mailman/listinfo/python-list
Re: "finally" for unit test
On Mar 23, 5:18 am, "killkolor" <[EMAIL PROTECTED]> wrote: > I have .. a single function that .. > works with files (takes input and outputs in the same file, no return > values). That function could cause problems. If your function reads in the whole file, modifies the data, and then overwrites the file, what would happen if something unforeseen happened and your program crashed after writing one line to the file? All the data in memory would go poof! and your file would contain 1 line it--effectively erasing the entire contents of the file. -- http://mail.python.org/mailman/listinfo/python-list
Re: exit to interpreter?
On Mar 23, 12:52 pm, belinda thom <[EMAIL PROTECTED]> wrote: > Hi, > > I'm writing a function that polls the user for keyboard input, > looping until it has determined that the user has entered a valid > string of characters, in which case it returns that string so it can > be processed up the call stack. My problem is this. I'd also like it > to handle a special string (e.g. 'quit'), in which case control > should return to the Python command line as opposed to returning the > string up the call stack. > > sys.exit seemed like a good choice, but it exits the python interpreter. > > I could use an exception for this purpose, but was wondering if > there's a better way? > > --b If you're using a function, wouldn't using the keyword "return" work? Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: exit to interpreter?
On Mar 23, 2007, at 11:04 AM, [EMAIL PROTECTED] wrote: > On Mar 23, 12:52 pm, belinda thom <[EMAIL PROTECTED]> wrote: >> Hi, >> >> I'm writing a function that polls the user for keyboard input, >> looping until it has determined that the user has entered a valid >> string of characters, in which case it returns that string so it can >> be processed up the call stack. My problem is this. I'd also like it >> to handle a special string (e.g. 'quit'), in which case control >> should return to the Python command line as opposed to returning the >> string up the call stack. >> >> sys.exit seemed like a good choice, but it exits the python >> interpreter. >> >> I could use an exception for this purpose, but was wondering if >> there's a better way? >> >> --b > > If you're using a function, wouldn't using the keyword "return" work? > > Mike No, because that just returns to the caller, which is not the Python interpreter. -- http://mail.python.org/mailman/listinfo/python-list
Re: On Java's Interface (the meaning of interface in computer programing)
Lew wrote: > But if Xah were being trollish, why didn't they jump on my response and > call me names? I'm not sure he's a proper troll. Unfortunately, he seems to be the kind of person who thinks that reading "Java for Dummies" makes one a self-sufficient expert on Java and philosopher of programming languages to boot, and who is very eager to bestow upon the world all his brilliant insights. At least, that explanation is consistent with his historic behavior. -- John W. Kennedy "Only an idiot fights a war on two fronts. Only the heir to the throne of the kingdom of idiots would fight a war on twelve fronts" -- J. Michael Straczynski. "Babylon 5", "Ceremonies of Light and Dark" * TagZilla 0.066 * http://tagzilla.mozdev.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Multi-line strings with formatting
Carsten Haese wrote:
> On Fri, 2007-03-23 at 09:54 -0700, [EMAIL PROTECTED] wrote:
>> When constructing a particularly long and complicated command to be
>> sent to the shell, I usually do something like this, to make the
>> command as easy as possible to follow:
>>
>> commands.getoutput(
>> 'mycommand -S %d -T %d ' % (s_switch, t_switch) +
>> '-f1 %s -f2 %s ' % (filename1, filename2) +
>> '> %s' % (log_filename)
>> )
>>
>> Can anyone suggest a better way to construct the command, especially
>> without the "+" sign at the end of each line (except the last) ? If I
>> take out the "+", then I need to move all the variables to the end, as
>> so:
>>
>> commands.getoutput(
>> 'mycommand -S %d -T %d '
>> '-f1 %s -f2 %s '
>> '> %s'
>> % (s_switch, t_switch, filename1, filename2, log_filename)
>> )
>>
>> or:
>>
>> commands.getoutput(
>> '''mycommand -S %d -T %d \
>> -f1 %s -f2 %s \
>> > %s'''
>> % (s_switch, t_switch, filename1, filename2, log_filename)
>> )
>
> You get the best of both worlds, i.e. one big multiline string with
> in-line parameters, by using a mapping:
>
> commands.getoutput(
>'''mycommand -S %(s_switch)d -T %(t_switch)d \
> -f1 %(filename1)s -f2 %(filename2)s \
> > %(log_filename)s'''
> % locals() )
>
> Of course I'm assuming that s_switch etc. are local variables. If
> they're not, well, they ought to be.
>
> -Carsten
>
>
If that doesn't suit then build a list:
l = [
'mycommand -S %d -T %d ' % (s_switch, t_switch) ,
'-f1 %s -f2 %s ' % (filename1, filename2) ,
'> %s' % (log_filename)
]
and then return commands.getoutput("".join(l)).
regards
Steve
--
Steve Holden +44 150 684 7255 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden
Recent Ramblings http://holdenweb.blogspot.com
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Re: #!/usr/bin/env python > 2.4?
In article <[EMAIL PROTECTED]>, Gabriel Genellina wrote: > Uh... I never thought it was an implied formula there - that F0 had to > come from 1.5 = 15 = 0xF. > I think it should be stated much more clearly. I'm not sure what you're saying. You are correct that the documentation is rather vague. The 'f0' comes from 'final release' I think. -- http://mail.python.org/mailman/listinfo/python-list
Re: Still the __new__ hell ...
Gabriel Genellina escreveu:
> En Wed, 21 Mar 2007 07:51:32 -0300, Bruno Desthuilliers
> <[EMAIL PROTECTED]> escribió:
>
>> Paulo da Silva a écrit :
>>> As a relatively inexperient
>>> in python, how could I know that a 'string' is an instance of
>>> basestring?
>>
>> By reading this newsgroup ?-)
>
> Or asking Python itself:
>
type("any string").mro()
> [, , ]
>
> --Gabriel Genellina
>
Good! ;-)
Paulo
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Join strings - very simple Q.
Hi! I was told in this NG that string is obsolet. I should use str methods. So, how do I join a list of strings delimited by a given char, let's say ','? Old way: l=['a','b','c'] jl=string.join(l,',') New way? Thanks Paulo -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
Paulo da Silva <[EMAIL PROTECTED]> writes: > Hi! > > I was told in this NG that string is obsolet. I should use > str methods. > > So, how do I join a list of strings delimited by a given > char, let's say ','? > > Old way: > > l=['a','b','c'] > jl=string.join(l,',') > > New way? Dunno if it's the "new way", but you can do: ''.join(l) -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
On Mar 23, 2:37 pm, Paulo da Silva <[EMAIL PROTECTED]> wrote: > Hi! > > I was told in this NG that string is obsolet. I should use > str methods. > > So, how do I join a list of strings delimited by a given > char, let's say ','? > > Old way: > > l=['a','b','c'] > jl=string.join(l,',') > > New way? > > Thanks > Paulo New way: l=['a','b','c'] jl=','.join(l) -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
Paul Rudin <[EMAIL PROTECTED]> writes: > Paulo da Silva <[EMAIL PROTECTED]> writes: > >> Hi! >> >> I was told in this NG that string is obsolet. I should use >> str methods. >> >> So, how do I join a list of strings delimited by a given >> char, let's say ','? >> >> Old way: >> >> l=['a','b','c'] >> jl=string.join(l,',') >> >> New way? > > Dunno if it's the "new way", but you can do: ''.join(l) Err, sorry - missed the comma out - it should be: ','.join(l) -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
> > I was told in this NG that string is obsolet. I should use > > str methods. > > > > So, how do I join a list of strings delimited by a given > > char, let's say ','? > > > > Old way: > > > > l=['a','b','c'] > > jl=string.join(l,',') > > > > New way? > > Dunno if it's the "new way", but you can do: ''.join(l) The OP wants the strings to be comma delimited: jl=','.join(l) -- http://mail.python.org/mailman/listinfo/python-list
Re: How to receive a FILE* from Python under MinGW?
En Fri, 23 Mar 2007 10:07:30 -0300, John Pye <[EMAIL PROTECTED]> escribió: > On Mar 23, 7:48 pm, "Gabriel Genellina" <[EMAIL PROTECTED]> > wrote: >> >> And replace all places where a Python file goes into a C extension, with >> exportable_file(f) > > What about calling mscvrt_get_osfhandle from inside the SWIG wrapper? > I tried this but it seemed that the function was not exported to the > DLL. The idea is to separate both worlds - _get_osfhandle must be called from the C runtime used by Python, not the one linked to your extension. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
ECCOMAS Thematic Conference VipIMAGE 2007 - Last Call for Papers
- (Apologies for cross-posting) International ECCOMAS Thematic Conference VipIMAGE 2007 - I ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING 17-19th October 2007, FEUP, Porto, Portugal http://www.fe.up.pt/VIPIMAGE We would appreciate if you could distribute this information by your colleagues and co-workers. - Dear Colleague, The International Conference VipIMAGE - I ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING will be held in the Faculty of Engineering of University of Porto, Porto, Portugal, on October 17-19, 2007. VipIMAGE will bring together several researchers from around the world representing several fields of study related to Computational Vision and Medical Image Processing, such as: Physics of Medical Imaging; Signal and image Processing; Simulation and Modelling; Data Interpolation, Registration and Compression; Telemedicine; Computer Aided Diagnosis, Surgery, Therapy, and Treatment; Computational Bioimaging and Visualization; Software Development and Grid Computing. The organizers would like to invite you to submit your contributions for VipIMAGE until the end of March. More details can be found in the conference website: http://www.fe.up.pt/VIPIMAGE. Important dates Submission of extended abstracts: March 31, 2007; Authors Notification: April 15, 2007; Lectures and Final Papers: May 15, 2007; Early registration fee: May 31, 2007. Proceedings The proceedings book of VipIMAGE will be will published by the Taylor & Francis Group. Invited Lectures - Automatic Generation of Computer Models from Multi-modal Bio-medical Imaging - Chandrajit Bajaj, USA - Computational Bioimaging and Visualization - Chris Johnson, USA - From Geometrical Models to Physiological Models of the Human Body - Hervé Delingette, France - Latest advances in Cardiovascular Informatics - Ioannis A. Kakadiaris, USA - Robust Algorithms for Deformable Contours - Jorge S. Marques, Portugal - Image Sequence Evaluation - Juan J. Villanueva, Spain - Fast Surface Segmentation and remeshing by finding geodesics - Laurent Cohen, France - Processing of Simultaneous acquisition of EEG and fMRI - Mario Forjaz Secca, Portugal - Automatic Construction of Statistical Shape Models using Non-Rigid Registration - Tim Cootes, UK - Theory of Digital Manifolds and its Applications to Medical Imaging - Valentin Brimkov, USA & Reinhard Klette, NZ We are looking forward to host you in Porto next October. Kind regards, João Manuel R. S. Tavares Renato Natal Jorge (conference co-chairs) -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
Mike Kent escreveu: ... > New way: > l=['a','b','c'] > jl=','.join(l) > I thank you all. Almost there ... I tried "".join(l,',') but no success ... :-( Paulo -- http://mail.python.org/mailman/listinfo/python-list
Re: How to receive a FILE* from Python under MinGW?
En Fri, 23 Mar 2007 16:34:22 -0300, Gabriel Genellina <[EMAIL PROTECTED]> escribió: >> What about calling mscvrt_get_osfhandle from inside the SWIG wrapper? >> I tried this but it seemed that the function was not exported to the >> DLL. > > The idea is to separate both worlds - _get_osfhandle must be called from > the C runtime used by Python, not the one linked to your extension. Ah, but you could import the msvcrt module and get it from there. *ONLY* get_osfhandle. The other function, open_osfhandle, must be from the runtime used by your extension. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: exit to interpreter?
belinda thom wrote: > On Mar 23, 2007, at 11:04 AM, [EMAIL PROTECTED] wrote: > >> On Mar 23, 12:52 pm, belinda thom <[EMAIL PROTECTED]> wrote: >>> Hi, >>> >>> I'm writing a function that polls the user for keyboard input, >>> looping until it has determined that the user has entered a valid >>> string of characters, in which case it returns that string so it can >>> be processed up the call stack. My problem is this. I'd also like it >>> to handle a special string (e.g. 'quit'), in which case control >>> should return to the Python command line as opposed to returning the >>> string up the call stack. >>> >>> sys.exit seemed like a good choice, but it exits the python >>> interpreter. >>> >>> I could use an exception for this purpose, but was wondering if >>> there's a better way? A custom-defined exception is probably the best way to jump out of a stack of nested calls. Mel. -- http://mail.python.org/mailman/listinfo/python-list
Re: exit to interpreter?
On Mar 23, 1:20 pm, belinda thom <[EMAIL PROTECTED]> wrote: > On Mar 23, 2007, at 11:04 AM, [EMAIL PROTECTED] wrote: > > > > > On Mar 23, 12:52 pm, belinda thom <[EMAIL PROTECTED]> wrote: > >> Hi, > > >> I'm writing a function that polls the user for keyboard input, > >> looping until it has determined that the user has entered a valid > >> string of characters, in which case it returns that string so it can > >> be processed up the call stack. My problem is this. I'd also like it > >> to handle a special string (e.g. 'quit'), in which case control > >> should return to the Python command line as opposed to returning the > >> string up the call stack. > > >> sys.exit seemed like a good choice, but it exits the python > >> interpreter. > > >> I could use an exception for this purpose, but was wondering if > >> there's a better way? > > >> --b > > > If you're using a function, wouldn't using the keyword "return" work? > > > Mike > > No, because that just returns to the caller, which is not the Python > interpreter. Sorry...I didn't realize you were calling from another function or functions. Duh. I agree with the other writer. Use a custom exception. -- http://mail.python.org/mailman/listinfo/python-list
Using Python to start SNMP service on remote XP hosts...
Hi, I am very new to Python and really just began studying and using it. I read that it was relatively easy to interact with Windows machines with Python and I am desperately looking for something to replace VBScript (not a big fan). I am currently deploying a Gentoo Linux SNMP server running Cacti in my network and would like my XP machines to report traps to this box. The SNMP service is not running by default on the machines in the network and instead of going to each one at a time, I thought I could write a script. Does anyone have any suggestions about how I go about accomplishing this? Thanks so much for any suggestions. -- http://mail.python.org/mailman/listinfo/python-list
Re: Join strings - very simple Q.
On Mar 24, 5:37 am, Paulo da Silva <[EMAIL PROTECTED]> wrote:
> Hi!
>
> I was told in this NG that string is obsolet. I should use
> str methods.
>
> So, how do I join a list of strings delimited by a given
> char, let's say ','?
>
> Old way:
>
> l=['a','b','c']
> jl=string.join(l,',')
>
> New way?
>
Self-help #1: reading the documentation:
http://www.python.org/doc/2.0/lib/string-methods.html
?
Change "0" to "5" to get the latest released version -- which hasn't
changed the description of the join method AFAICT.
Self-help #2: help() at the interactive prompt:
Python 2.2.3 (#42, May 30 2003, 18:12:08) [MSC 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
| >>> help("".join)
Help on built-in function join:
join(...)
S.join(sequence) -> string
Return a string which is the concatenation of the strings in the
sequence. The separator between elements is S.
| >>>
OK, I'll bite: This was "new" in late 2000 when Python 2.0 was
released. Where have you been in the last ~6.5 years?
HTH,
John
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Re: Using Python to start SNMP service on remote XP hosts...
On Mar 23, 2:51 pm, "KDawg44" <[EMAIL PROTECTED]> wrote: > Hi, > > I am very new to Python and really just began studying and using it. > I read that it was relatively easy to interact with Windows machines > with Python and I am desperately looking for something to replace > VBScript (not a big fan). > > I am currently deploying a Gentoo Linux SNMP server running Cacti in > my network and would like my XP machines to report traps to this box. > The SNMP service is not running by default on the machines in the > network and instead of going to each one at a time, I thought I could > write a script. > > Does anyone have any suggestions about how I go about accomplishing > this? > > Thanks so much for any suggestions. It looks like you can use Tim Golden's WMI module to do what you need. See this other post for info: http://www.thescripts.com/forum/thread541366.html You'll have to find out the exact name of the service, loop through and use an IF to test for it and when it is found, try starting it. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
Jorgen Grahn wrote: > On 23 Mar 2007 03:47:14 -0700, Godzilla <[EMAIL PROTECTED]> wrote: >> Hello, >> >> How do you create/spawn new processes in XP over telnet using python? >> I.e. I would like to create a new process and have it running in the >> background... > > Ssh -- or even rsh -- are better choices than telnet for these things. > For some reason, they are not standard in Windows, though. > > ssh somewhere some command with arguments > rsh somewhere some command with arguments > > compared to > > telnet somewhere > > and then performing expect-like things (basically simulating > someone typing "some command with arguments" in the telnet > session). + for an sshd running as a service under XP, look at CopSSH. + hope started process doesn't want a GUI... else, look at UltraVNC running as daemon, and port redirection using ssh. > >> when I terminate the telnet connection, I would what the >> spawned processes to keep running until I shut it off... > > That's a function of the remote OS; what happens when its terminal > goes away is not under the control of the client side. Maybe the process starting job can be done by a Python program running as Windows service and waiting for requests on a port (or Pyro object or Corba object...). No need for telnet/ssh connection, no logout problem. Just care of possible security problems :-) -- http://mail.python.org/mailman/listinfo/python-list
Python object overhead?
I'm trying to use Python to work with large pipe ('|') delimited data
files. The files range in size from 25 MB to 200 MB.
Since each line corresponds to a record, what I'm trying to do is
create an object from each record. However, it seems that doing this
causes the memory overhead to go up two or three times.
See the two examples below: running each on the same input file
results in 3x the memory usage for Example 2. (Memory usage is
checked using top.)
This happens for both Python 2.4.3 on Gentoo Linux (64bit) and Python
2.3.4 on CentOS 4.4 (64bit).
Is this "just the way it is" or am I overlooking something obvious?
Thanks,
Matt
Example 1: read lines into list:
# begin readlines.py
import sys, time
filedata = list()
file = open(sys.argv[1])
while True:
line = file.readline()
if len(line) == 0: break # EOF
filedata.append(line)
file.close()
print "data read; sleeping 20 seconds..."
time.sleep(20) # gives time to check top
# end readlines.py
Example 2: read lines into objects:
# begin readobjects.py
import sys, time
class FileRecord:
def __init__(self, line):
self.line = line
records = list()
file = open(sys.argv[1])
while True:
line = file.readline()
if len(line) == 0: break # EOF
rec = FileRecord(line)
records.append(rec)
file.close()
print "data read; sleeping 20 seconds..."
time.sleep(20) # gives time to check top
# end readobjects.py
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ANN: wxPython 2.8.3.0
Announcing
--
The 2.8.3.0 release of wxPython is now available for download at
http://wxpython.org/download.php. This release includes a number of
bug fixes and also some new enhancements, including updates to the
XRCed tool and the new InspectionTool.
Source code is available, as well as binaries for both Python 2.4 and
2.5, for Windows and Mac, as well some pacakges for various Linux
distributions. A summary of changes is listed below and also at
http://wxpython.org/recentchanges.php.
What is wxPython?
-
wxPython is a GUI toolkit for the Python programming language. It
allows Python programmers to create programs with a robust, highly
functional graphical user interface, simply and easily. It is
implemented as a Python extension module that wraps the GUI components
of the popular wxWidgets cross platform library, which is written in
C++.
wxPython is a cross-platform toolkit. This means that the same program
will usually run on multiple platforms without modifications.
Currently supported platforms are 32-bit Microsoft Windows, most Linux
or other Unix-like systems using GTK2, and Mac OS X 10.3+, in most
cases the native widgets are used on each platform to provide a 100%
native look and feel for the application.
Changes in 2.8.3.0
--
Added wx.ToolBar.SetToolNormalBitmap and SetToolDisabledBitmap
methods. (Keep in mind however that the disabled bitmap is currently
generated on the fly by most native toolbar widgets, so this
SetToolDisabledBitmap method won't have any affect on them...)
Refactored the inspection tool such that it can be used as a wx.App
mix-in class as it was used before (with the wx.lib.mixins.inspect
module) and also as a non mix-in tool (using
wx.lib.inspect.InspectionTool).
Add wx.lib.mixins.treemixin from Frank Niessink.
Added the wx.SizerFlags class, and also added AddF, InsertF and
PrependF methods to wx.Sizer. The wxSizerFlags class provides a
convienient and easier to read way to add items to a sizer. It was
added as a new set of methods of the wx.Sizer class so as to not
disturb existing code. For example, instead of writing::
sizer.Add(ctrl, 0, wx.EXPAND | wx.ALL, 10)
you can now write::
sizer.AddF(ctrl, wx.SizerFlags().Expand().Border(wx.ALL,10))
Will Sadkin provided a patch for the wx.lib.masked package that fixes
its support for using the navigation keys on the numeric keypad.
wx.lib.plot: patch #1663937 to allow user to turn off scientific
notation on plot.
wxGTK: Most of the remaining TODOs for the wx.GraphicsContext on wxGTK
have been done. This includes implementations for GetTextExtent,
Clip, DrawBitmap, fixing the drawing position of text to be at the
upper left corner instead of the baseline, etc.
wx.lib.customtreectrl patches from Andrea:
1. ExpandAll has been renamed as ExpandAllChildren, and the new
ExpandAll now takes no input arguments (consistent with
wx.TreeCtrl)
2. ctstyle keyword is now defaulted to 0: every style related to
CustomTreeCtrl and the underlying wx.PyScrolledWindow should be
declared using the keyword "style" only. For backward
compatibility, ctstyle continues to work as I merged ctstyle and
style in the __init__ method.
3. GetClassDefaultAttributes is now a classmethod.
4. UnselectAll bug fixed.
Renamed the wx.lib.inspect and wx.lib.mixins.inspect modules to
inspection, in order to avoid conflicts with the inspect module in the
standard Python library.
Lots of changes to XRCed from Roman Rolinsky:
* Preferences for default "sizeritem" parameters for new panels and
controls can be configured ("File">"Preferences...").
* Implemented comment object for including simple one-line comments
and comment directives as tree nodes. No validation is performed
for a valid XML string so comments must not contain "-->". Comment
directive is a special comment starting with '%' character,
followed by a line of python code. It is executed using 'exec'
when the resource file is opened. This is useful to import plugin
modules containing custom handlers which are specific to the
resource file, hovewer this is of course a security hole if you
use foreign XRC files. A warning is displayed if the preference
option 'ask' is selected (by default).
* Added support for custom controls and plugin modules. Refer to
this wxPythonWiki for the details:
http://wiki.wxpython.org/index.cgi/XRCed#custom
* Tool panel sections can be collapsed/expanded by clicking on the
label of a tool group.
* Some undo/redo and other fixes.
* Fixes for wxMSW (notebook highlighting, control sizes, tree
Unselect).
* Notebook page highlighting fix. Highlight resizes when the window
is resized. ParamUnit spin button detects event handler re-entry
(wxGTK probably has a bug in wxSpinButton with repeated events).
* Fix for dealing with empty 'growable' property, u
Re: Python object overhead?
On Fri, 23 Mar 2007 15:11:35 -0600, Matt Garman wrote: > > Is this "just the way it is" or am I overlooking something obvious? > Matt, If you iterate over even the smallest object instantiation a large amount of times, it will be costly compared to a simple list append. I don't think you can get around some overhead with the objects. However, in terms of generally efficiency not specifically related to object instantiation, you should look into xreadlines(). I'd suggest doing the following instead of that while loop: for line in open(sys.argv[1]).xreadlines(): .. -- Mark Nenadov -> skype: marknenadov, web: http://www.marknenadov.com -> "Glory is fleeting, but obscurity is forever." -- Napoleon Bonapart -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
This reminds me of something I once wanted to do: How can I install Python in a totally non-gui way on Windows (without the use of VNC)? I think I was telnetted into a computer (or something like that) and I was unable to run the usual Python installer because it uses a GUI. Laurent Pointal wrote: Jorgen Grahn wrote: On 23 Mar 2007 03:47:14 -0700, Godzilla <[EMAIL PROTECTED]> wrote: Hello, How do you create/spawn new processes in XP over telnet using python? I.e. I would like to create a new process and have it running in the background... Ssh -- or even rsh -- are better choices than telnet for these things. For some reason, they are not standard in Windows, though. ssh somewhere some command with arguments rsh somewhere some command with arguments compared to telnet somewhere and then performing expect-like things (basically simulating someone typing "some command with arguments" in the telnet session). + for an sshd running as a service under XP, look at CopSSH. + hope started process doesn't want a GUI... else, look at UltraVNC running as daemon, and port redirection using ssh. when I terminate the telnet connection, I would what the spawned processes to keep running until I shut it off... That's a function of the remote OS; what happens when its terminal goes away is not under the control of the client side. Maybe the process starting job can be done by a Python program running as Windows service and waiting for requests on a port (or Pyro object or Corba object...). No need for telnet/ssh connection, no logout problem. Just care of possible security problems :-) -- Shane Geiger IT Director National Council on Economic Education [EMAIL PROTECTED] | 402-438-8958 | http://www.ncee.net Leading the Campaign for Economic and Financial Literacy begin:vcard fn:Shane Geiger n:Geiger;Shane org:National Council on Economic Education (NCEE) adr:Suite 215;;201 N. 8th Street;Lincoln;NE;68508;United States email;internet:[EMAIL PROTECTED] title:IT Director tel;work:402-438-8958 x-mozilla-html:FALSE url:http://www.ncee.net version:2.1 end:vcard -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
On Fri, Mar 23, 2007 at 03:11:35PM -0600, Matt Garman wrote:
> I'm trying to use Python to work with large pipe ('|') delimited data
> files. The files range in size from 25 MB to 200 MB.
>
> Since each line corresponds to a record, what I'm trying to do is
> create an object from each record. However, it seems that doing this
> causes the memory overhead to go up two or three times.
>
> See the two examples below: running each on the same input file
> results in 3x the memory usage for Example 2. (Memory usage is
> checked using top.)
[snip]
When you are just appending all the lines in a big list your overhead
looks like:
records = []
for line in file_ob:
records.append(line)
But when you wrap each line in a small class the overhead is
records = []
for line in file_ob:
records.append(line) # the actual string
records.append(object()) # allocation for the object instance
records.append({}) # dictionary for per instance attributes
For small strings like dictionary words the overhead over the second
is about 5x the overhead of a plain list. Most of it is the per
instance dictionary.
If you make the record a new style class (inherit from object) you can
specify the __slots__ attribute on the class. This eliminates the per
instance dictionary overhead in exchange for less flexibility.
Another solution would be to only wrap the lines as they are accessed.
Make one class that holds a collection of raw records. Have that return
a fancy class wrapping each record right before it is used and discarded.
class RecordCollection(object):
def __init__(self, raw_records):
self.raw_records = raw_records
def __getitem__(self, i):
return Record(self.raw_records[i])
If you are operating on each of the records in serial you only have
the class overhead for one at any given time.
Hope that helps,
-Jack
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Re: Python object overhead?
En Fri, 23 Mar 2007 18:27:25 -0300, Mark Nenadov <[EMAIL PROTECTED]> escribió: > I'd suggest doing the following instead of that while loop: > > for line in open(sys.argv[1]).xreadlines(): Poor xreadlines method had a short life: it was born on Python 2.1 and got deprecated on 2.3 :( A file is now its own line iterator: f = open(...) for line in f: ... -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
En Fri, 23 Mar 2007 18:11:35 -0300, Matt Garman <[EMAIL PROTECTED]> escribió: > Example 2: read lines into objects: > # begin readobjects.py > import sys, time > class FileRecord: > def __init__(self, line): > self.line = line > records = list() > file = open(sys.argv[1]) > while True: > line = file.readline() > if len(line) == 0: break # EOF > rec = FileRecord(line) > records.append(rec) > file.close() > print "data read; sleeping 20 seconds..." > time.sleep(20) # gives time to check top > # end readobjects.py Your file record requires at least two objects in addition to the line itself: the FileRecord instance and the dictionary instance (__dict__) used to hold its attributes. You can use a new style class with __slots__ to omit that dictionary: class FileRecord(object): __slots__ = ['line'] def __init__(self, line): self.line = line or defer instance creation: class FileRecords(list): # store here all the lines, maybe using readlines() def __getitem__(self, index): return FileRecord(list.__getitem__(self, index)) -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
On text processing
Hi list, I'm in a process of rewriting a bash/awk/sed script -- that grew to big -- in python. I can rewrite it in a simple line-by-line way but that results in ugly python code and I'm sure there is a simple pythonic way. The bash script processed text files of the form: ### key1value1 key2value2 key3value3 key4value4 spec11 spec12 spec13 spec14 spec21 spec22 spec23 spec24 spec31 spec32 spec33 spec34 key5value5 key6value6 key7value7 more11 more12 more13 more21 more22 more23 key8value8 ### I guess you get the point. If a line has two entries it is a key/value pair which should end up in a dictionary. If a key/value pair is followed by consequtive lines with more then two entries, it is a matrix that should end up in a list of lists (matrix) that can be identified by the key preceeding it. The empty line after the last line of a matrix signifies that the matrix is finished and we are back to a key/value situation. Note that a matrix is always preceeded by a key/value pair so that it can really be identified by the key. Any elegant solution for this? -- http://mail.python.org/mailman/listinfo/python-list
Re: On Java's Interface (the meaning of interface in computer programing)
Lew <[EMAIL PROTECTED]> writes: > But if Xah were being trollish, why didn't they jump on my response > and call me names? Xah never replies to the threads he starts. At least, I've never known him to do so. > I still think that analysis of the original post is a useful exercise > to learn Java. Maybe so - I don't know enough Java to comment on that. But there's nothing useful to cross-posting the original to a fistful of non-Java lists. > The more subtle Xah or other > minions of Satan get in their presentations, the more interesting the > forensic exercise to dig out the truth. The truth is that Xah wants to start an argument. He cross-posts for that reason, so that the "forensic exercise" you're speaking of then becomes an argument among proponents of the various languages about which language is closer to the "truth". Don't take my word for it though - check Google Groups. You'll find he's been doing this for a long time. sherm-- -- Web Hosting by West Virginians, for West Virginians: http://wv-www.net Cocoa programming in Perl: http://camelbones.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
Re: fine grain logging cotrol
Peter Otten wrote:
> Eric S. Johansson wrote:
>
> Here is yet another revision of my example then:
it's making more and more sense although I don't quite follow 'property'
quite yet. But I see that get_logger is invoked prior to the
__logger.info call.
I was looking at how to implement one of my other requirements
(conditional based on a predicate) and I see that I could use a filter.
I've experimented a little but come up empty. This is what I changed:
class filter_test (logging.Filter):
test_names = { "Felis.alpha" : True,
"Catus.alpha" : False,
}
def ___init__ (self, name):
"""simple filter test """
self.name = name
def filter(self, record):
"""test and forget """
return test_names.has_key(self.name) and test_names[self.name]
class LoggedType(type):
def __new__(mcl, name, bases, classdict):
def get_logger(self):
tag = "%s.%s" % (name,sys._getframe(1).f_code.co_name)
lgr = logging.getLogger(tag)
lgr.addFilter(filter_test)
return lgr
classdict["_%s__logger" % name] = property(get_logger)
return type.__new__(mcl, name, bases, classdict)
It's probably real obvious but I keep getting a:
File "C:\Python24\lib\logging\__init__.py", line 539, in filter
if not f.filter(record):
TypeError: unbound method filter() must be called with filter_test
instance as first argument (got LogRecord instance instead)
I'm puzzled that I thought I was adding the filter object at the right
point in time with addFilter. I wouldn't be surprised if I was totally
off base but I'd be interested in figuring out how I went off the rails
so I can fill in the knowledge.
---eric
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