🌐 Mailman 3 June 2009 - Python-list - python.org

Re: renice
by Dan July 14, 2009

July 14, 2009

On Oct 26, 4:30 am, mokhtar <mbmessa...(a)yahoo.com> wrote: > Hi > > Is it possible to renice the python process executing the current python > script ?:confused: > -- > View this message in context:http://www.nabble.com/renice-tf4695834.html#a13422771 > Sent from the Python - python-list mailing list archive at Nabble.com. On UNIX: >>> import os >>> os.system("renice -n %d %d" % ( new_nice, os.getpid() ) ) (untested) I don't know if windows has the concept of renice... -Dan

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python3 fail to start
by ts July 9, 2009

July 9, 2009

i just install the python 3.1 dmg onto my mac. when i run python3, it fail with : Fatal Python error: Py_Initialize: can't initialize sys standard streams LookupError: unknown encoding: Abort trap couldnt understand the problem. anyone can help?

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Re: waling a directory with very many files
by Steven D'Aprano July 8, 2009

July 8, 2009

On Sun, 14 Jun 2009 22:35:50 +0200, Andre Engels wrote: > On Sun, Jun 14, 2009 at 6:35 PM, tom<fsb(a)thefsb.org> wrote: >> i can traverse a directory using os.listdir() or os.walk(). but if a >> directory has a very large number of files, these methods produce very >> large objects talking a lot of memory. >> >> in other languages one can avoid generating such an object by walking a >> directory as a liked list. for example, in c, perl or php one can use >> opendir() and then repeatedly readdir() until getting to the end of the >> file list. it seems this could be more efficient in some applications. >> >> is there a way to do this in python? i'm relatively new to the >> language. i looked through the documentation and tried googling but >> came up empty. > > What kind of directories are those that just a list of files would > result in a "very large" object? I don't think I have ever seen > directories with more than a few thousand files... You haven't looked very hard :) $ pwd /home/steve/.thumbnails/normal $ ls | wc -l 33956 And I periodically delete thumbnails, to prevent the number of files growing to hundreds of thousands. -- Steven

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Re: SSH utility
by Sean DiZazzo July 8, 2009

July 8, 2009

On Aug 11, 5:17 am, Edwin.Mad...(a)VerizonWireless.com wrote: > for similar tasks, I use pexpecthttp://pypi.python.org/pypi/pexpect. > > spawning bash process and simulate an interactive session. Here sending ls command, retrieving results and exiting. In the spawned process ssh or any other command, is just another command. > > ------------actual session-------------------------- > $ python > Python 2.5.1 (r251:54863, May 18 2007, 16:56:43) > [GCC 3.4.4 (cygming special, gdc 0.12, using dmd 0.125)] on cygwin > Type "help", "copyright", "credits" or "license" for more information.>>> import pexpect > >>> c = pexpect.spawn('/bin/bash') > >>> c.expect([pexpect.TIMEOUT, pexpect.EOF, '\$ ']) > 2 > >>> c.before, c.after > > ('\x1b[?1034hmadared@NJWARHQD0IT696A:~\r\n', '$ ')>>> c.sendline('ls') > 3 > >>> c.expect([pexpect.TIMEOUT, pexpect.EOF, '\$ ']) > 2 > >>> c.before, c.after > > ('ls\r\x.txt xx.txt xy.txt y.txt\r\nmadared@NJWARHQD0IT696A:~\r\n', '$ ')>>> c.sendline('exit') > 5 > >>> c.expect([pexpect.TIMEOUT, pexpect.EOF, '\$ ']) > 1 > >>> c.before, c.after > > ('exit\r\nexit\r\n', <class 'pexpect.EOF'>)>>> exit() > > madared@NJWARHQD0IT696A:~ > $ > --------------------------------------------------------------- > > hope that helps. > > regards. > Edwin > > -----Original Message----- > From: python-list-bounces+edwin.madari=verizonwireless....(a)python.org > > [mailto:python-list-bounces+edwin.madari=verizonwireless....@python.org] > On Behalf Of James Brady > Sent: Monday, August 11, 2008 12:26 AM > To: python-l...(a)python.org > Subject: SSH utility > > Hi all, > I'm looking for a python library that lets me execute shell commands > on remote machines. > > I've tried a few SSH utilities so far: paramiko, PySSH and pssh; > unfortunately all been unreliable, and repeated questions on their > respective mailing lists haven't been answered... > > It seems like the sort of commodity task that there should be a pretty > robust library for. Are there any suggestions for alternative > libraries or approaches? > > Thanks! > James > --http://mail.python.org/mailman/listinfo/python-list > > The information contained in this message and any attachment may be > proprietary, confidential, and privileged or subject to the work > product doctrine and thus protected from disclosure. If the reader > of this message is not the intended recipient, or an employee or > agent responsible for delivering this message to the intended > recipient, you are hereby notified that any dissemination, > distribution or copying of this communication is strictly prohibited. > If you have received this communication in error, please notify me > immediately by replying to this message and deleting it and all > copies and backups thereof. Thank you. I second pexpect and the nice little module that comes with it ssh_session.py. Been using it for ages now! ~Sean

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why PyObject_VAR_HEAD?
by kio July 7, 2009

July 7, 2009

Hi, I'm studying the CPython source code. I don’t quite understand why they’re using PyObject_VAR_HEAD to define struct like PyListObject. To define such kind of struct, could I use _PyObject_HEAD_EXTRA as a header and add "items" pointer and "allocated" count explicity? Is there any difference? Thanks. Eric

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Re: Wrapping comments
by Nick Craig-Wood July 5, 2009

July 5, 2009

Rhodri James <rhodri(a)wildebst.demon.co.uk> wrote: > On Sun, 10 May 2009 08:32:23 +0100, Tobias Weber <towb(a)gmx.net> wrote: > > > In article <m2bpq2ngup.fsf(a)googlemail.com>, > > Arnaud Delobelle <arnodel(a)googlemail.com> wrote: > > > >> A simple Alt-Q will reformat everything nicely. > > > > Now that's something. Thanks! > > > > (still not gonna use software that doesn't let me type # because it's > > alt+3 on a UK layout; having to re-learn or configure that is just sick) > > What on earth are you talking about? '#' has its own key on a UK layout > (shared with '~', but you know what I mean), just to the left of the > RETURN key. Emacs is my editor of choice, and I've never once come > across anything like this. You probably haven't used MAC OS X then! I vnc to a mac and use emacs and I just can't type a #. "Ctrl-Q 43 Return" is my best effort! -- Nick Craig-Wood <nick(a)craig-wood.com> -- http://www.craig-wood.com/nick

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Re: Direct interaction with subprocess - the curse of blocking I/O
by Nobody July 2, 2009

July 2, 2009

On Mon, 29 Jun 2009 21:15:52 +0200, Pascal Chambon wrote: > I've had real issues with subprocesses recently : from a python script, > on windows, I wanted to "give control" to a command line utility, i.e > forward user in put to it and display its output on console. Are you talking about a popen(..., 'w') situation? I.e. where Python feeds data to the child's stdin but the child's stdout doesn't go through Python? Or a slave process, where both stdin and stdout/stderr are piped to/from Python? The latter is inherently tricky (which is why C's popen() lets you connect to stdin or stdout but not both). You have to use either multiple threads, select/poll, or non-blocking I/O. If the child's output is to the console, it should presumably be the former, i.e. piping stdin but allowing the child to inherit stdout, in which case, where's the problem? Or are you piping its stdout via Python for the hell of it?

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whizBase vs. Python
by NurAzije July 2, 2009

July 2, 2009

Hi, I am working on a study and I need expert opinion, I did not work with Python before, can anyone help me with a comparison between WhizBase (www.whizbase.com) and Python please. Thank you in advance, Ashraf Gheith

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Re: pep 8 constants
by Steven D'Aprano July 2, 2009

July 2, 2009

On Mon, 29 Jun 2009 22:37:15 -0400, Eric S. Johansson wrote: > Steven D'Aprano wrote: ... >> Sounds to me that your speech environment needs a command to turn >> capslock on and off, and your problem with PEP 8 is solved: > > you haven't used recognition, have you? No. >> x equals caps on red caps off plus three > > it also means "red" is a single utterance. "RED" is three utterances. > You've just tripled vocal load for single word which means vat you just > cut my ability to work by two thirds. That assumes that every word is all caps. In practice, for real-life Python code, I've tripled the vocal load of perhaps one percent of your utterances, which cuts your productivity by 2%. If you have 10000 words in you per day, and one percent get wrapped with a leading and trailing "capslock", you have: 9900 regular words plus 100 constants versus 9700 regular words plus 100 constants plus 200 by capslock. Your productivity goes down by 200 words out of 10,000, or two percent. >>> Heck, have you ever noticed how most Python smart editors can't even >>> indent properly according to local contexts. Emacs is the only one and >>> even that one sometimes fails >> >> I use kwrite for editing, and I can't say I've ever noticed a failure. > > okay, it fails from a speech recognition user perspective. Put the > cursor on the line and hit the tab key. Insert spaces/tabs in the line > of text. Not good for speech recognition. If mess of indentation and > hit the tab key, it doesn't automatically indent to the right location. > I'll be damned if I'm in the sit there speaking > "tabkeytabkeytabkeytabkeytabkey" because the error should take care of > it for me and save my voice. Like I said, Emacs does it correctly and > nobody else does as far as I can tell. I don't understand what you're describing. If you set kwrite to use "Python style" indent mode, then starting a new line will automatically indent to either the current indent level, or one extra indent level if the line ends with a colon. You shouldn't need to indent forward more than one level at a time when writing Python code, although you will need to dedent multiple levels on occasion. > I only have about 1000 keystrokes equivalents today in my hands. Where > am I going to use them? Try adding (driving), preparing food, personal > hygiene, or typing PEP-8 compliant code? Your choice naturally. > You're looking at it from the classical anti-accommodation perspective. > Don't change the convention, give us the tools so we can comply with > what the rest of you do. Just a minute. You're the one who started this discussion rejecting the convention. Your first post started off: "I reject this convention..." and then finished with "so I reject pep 8 because I have no voice safe alternative" Do you blame us for reading this as a protest against uppercase identifiers? Now you're saying you're happy for us to keep the all-uppercase convention and just want better tools. Okay, you want better tools. Great. If you're attempting to raise the profile of disabled programmers, you've done so, but what exactly are you expecting? I've already said it's your right to reject the convention for your own code. Go right ahead. This is only a problem if you're editing other people's code which is using uppercase constants. You've rejected capslock red capslock because it takes three utterances, but said you use constant_red instead. That's two utterances, saving you only one. If you actually have to say the underscore, your convention takes six syllables versus five for my idea. >> Especially when these coding conventions are entirely optional. > > these conventions are religion for some special if you want to > contribute code. Does your editor have search and replace? Before you contribute code, do a global replacement of constant_red for RED. > But look at the bigger issue. Yes, we get it. It sucks to have a physical disability. The universe isn't arranged to make it easy for those who do, and even systems built by people are only indifferently suitable. So, let's get down to practical matters: Do you wish to register a protest against all-caps constants in PEP 8? Do you wish to ask the Python Dev team to rethink their decision? Do you wish to raise the profile of disabled programmers? Do you wish to start a project developing a better, smarter editor, and are looking for volunteers? -- Steven

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Re: pep 8 constants
by Steven D'Aprano July 2, 2009

July 2, 2009

On Mon, 29 Jun 2009 11:49:04 -0400, Eric S. Johansson wrote: > alex23 wrote: >> "Eric S. Johansson" <e...(a)harvee.org> wrote: >>> no, I know the value if convention when editors can't tell you >>> anything about the name in question. I would like to see more support >>> for disabled programmers like myself and the thousands of programmers >>> injured every year and forced to leave the field. seriously, there is >>> no money in disability access especially for programmers. >> >> Well, if we can't use conventions like uppercasing, camelcasing and >> underscoring, what are you recommending we do instead? > > help build a smart editing environment please. Why do you think a smart editing environment is in opposition to coding conventions? Surely an editor smart enough to know a variable name spoken as "pear tree" is an instance and therefore spelled as pear_tree (to use your own example) would be smart enough to know a variable name spoken as "red" is a constant and therefore spelled "RED"? Sounds to me that your speech environment needs a command to turn capslock on and off, and your problem with PEP 8 is solved: x equals caps on red caps off plus three > Heck, have you ever noticed how most Python smart editors can't even > indent properly according to local contexts. Emacs is the only one and > even that one sometimes fails I use kwrite for editing, and I can't say I've ever noticed a failure. > I've lived this works and probably have put more deep thought and 8kloc > into it because I do not accept circures tricks as a way of life. I > want it to work right and I know how to do it. I just don't have the > hands and hte money to pay me to do it. You're using a speech interface, right? You've written about "putting a gun to your wrists", said you can't follow PEP 8 because it's not voice safe, and generally given the impression that you can't use a keyboard. So... just how do you get "hte" from saying "the"? If you are using a keyboard to type this post, then surely it's not such a huge imposition to type a couple of words in all caps here and there while you speak the rest of the code? <speak> x equals </speak> <type> <caplock> R E D </type> <speak> plus three </speak> I know that doesn't resolve the issue for those people who truly can't use a keyboard at all, even for a single character, but it's unfair to insist that the only permitted coding conventions are the ones suitable for the tiny minority who, frankly, are going to have problems no matter what coding conventions we have. Especially when these coding conventions are entirely optional. -- Steven

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