🌐 Mailman 3 January 2002 - Python-list - python.org

Please comment on Draft PEP for Enhanced Generators
by Raymond Hettinger Feb. 6, 2002

Feb. 6, 2002

I have written a draft PEP summarizing proposed enhancements to generators: http://users.javanet.com/~othello/download/genpep.htm The draft reflects all the comments I've received to date on the threads where the ideas where first proposed. Please post your comments (and maybe a little encouragment) here on comp.lang.py or email them directly to me. Thank you, Raymond Hettinger othello(a)javanet.com

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Re: lists, uppercase?
by Steve Holden Feb. 6, 2002

Feb. 6, 2002

"Bjorn Pettersen" <BPettersen(a)NAREX.com> wrote in message news:mailman.1012427749.9821.python-list@python.org... > From: maximilianscherr [mailto:MaximilianScherr@T-Online.de] > > just two questions this time: > [list reversal] > how can i get to know if a string is totally uppercase? if myString == myString.upper(): # it's all upper case Well, not strictly true: what that tells you is that there are no lower-case letters in the string. But "123" == "123".upper() even though there's not an upper case character to be seen. Depends exactly what the requirement is, I suspect. regards Steve -- Consulting, training, speaking: http://www.holdenweb.com/ Python Web Programming: http://pydish.holdenweb.com/pwp/

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Re: Rue the day...
by rony.steelandt＠bucodi.com Feb. 5, 2002

Feb. 5, 2002

"Chris Gonnerman" <chris.gonnerman(a)newcenturycomputers.net> wrote in message news:<mailman.1012274265.29834.python-list(a)python.org>... > Guys, I know we have the reputation as the nicest bunch of nerds on > the 'Net, but Rue is consuming more of our time and bandwidth than spam. > Despite his comments to the contrary, no one on this list gives him > any credence. Yes it's true that there is a nice bunch here. BUT what keeps me amazing here, is : 1. How you keep defending the Python language over and over again. Don't understand me wrong, Python is a VERY good language and we are using it for years now, like a lot of you. But each time some guy asks here a question like 'Should i use Python of Perl' or 'Python or C for a real world application' evrybody here starts here to defend Python. IMHO this is useless, since allready the question is stupid... The language you want to choose depends on a lot of items and not only wether you have to use brackets of indents to structure code block, or to have to declare variables or not. Even the developmentspeed issues like you see here often depends on a lot of things, we have as an example 2 C goeroes in house that develop at the speed of other python applications, only the applications will be different and THAT is the reason that some application is written in C and others in Python... So if someone asks if he should use Python , the only real answer could be 'Have a look at it, try it and decide... you're a big boy'. 2. How you keep answerring the same questions over and over again. Style 'WIch IDE to use to develop with python' or worse 'Does python have a compiler'. If you think this is just a small part of the question here, take google and do a search on IDE or compiler on this group. But it's true you are a great bunch here . Rony > > Realize that he lives on this BS. His "project" does not exist except > in his fevered brain; VIC seems to be everything and nothing. He's been > "working" on it for something like, what, 10 years, and it is still > no more than a website and some Python code that seems to do nothing. > > It doesn't matter whether your response is kind or cruel, agreeable or > argumentative, it's the *attention* he craves. Just don't talk to him. > Not at all, even if he calls you terrible names. If we ignore him long > enough, he'll eventually go away. > > Chris Gonnerman -- chris.gonnerman(a)newcenturycomputers.net > http://newcenturycomputers.net

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tt = a, b = t
by rihad Feb. 5, 2002

Feb. 5, 2002

Playing with Python goes on.... tup = 1, 2 tuptup = a, None = tup >>> tup (1, 2) >>> a 1 >>> tuptup (1, 2) How did 2 manage to propagate to tuptup through None?

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Re: RELEASED - StandaloneZODB 1.0 release candidate 1
by woodsplitter＠rocketmail.com Feb. 5, 2002

Feb. 5, 2002

> Today we are releasing StandaloneZODB 1.0 release candidate 1. We > expect to release the final version on 1-Feb-2002. StandaloneZODB-1.0-rc1 + Standard Python 2.2 + Visual C++ 6.0 + WinNT 4.0-SP6a: "python setup.py build" -- works fine "python setup.py test" -- throws this exception Traceback (most recent call last): File "lib.win32-2.2\ZEO\tests\winserver.py", line 61, in ? main(sys.argv[1], sys.argv[2], sys.argv[3:]) File "lib.win32-2.2\ZEO\tests\winserver.py", line 50, in main klass = load_storage_class(storage_name) File "lib.win32-2.2\ZEO\tests\winserver.py", line 45, in load_storage_class package = __import__("ZODB." + name) File "lib.win32-2.2\ZODB\FileStorage.py", line 133, in ? from fsIndex import fsIndex File "lib.win32-2.2\ZODB\fsIndex.py", line 36, in ? from BTrees._fsBTree import fsBTree as _fsBTree File "lib.win32-2.2\BTrees\__init__.py", line 11, in ? import Interfaces File "lib.win32-2.2\BTrees\Interfaces.py", line 98, in ? class IDictionaryIsh(IKeyed, Interface.Standard.MinimalDictionary): AttributeError: 'module' object has no attribute 'MinimalDictionary'

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Backwards Compatibility of Python versions
by Sheila King Feb. 4, 2002

Feb. 4, 2002

I'm trying to persuade my web host to install a more recent version of Python than 1.5.2. Yes, they have RH Linux system with the default 1.5.2. While I've installed my own more recent version of Python within my own space, since all of my "friends" at the webhost only have access to 1.5.2, I usually try to restrict my code to a subset that will run under 1.5.2 so that I can distribute it to others at my host. In the past, the system admin has mentioned that he is not wanting to upgrade Python because the system utilities in RH Linux depend on the 1.5.2 and he doesn't want to break anything. Recently, I brought this topic up again (in the community discussion forums) and asked if it wouldn't be possible to install a more recent version *ALONGSIDE* the system default version. (I know the answer to this is 'yes', but I'm trying to 'suggest' it...) He did respond that he is *thinking* about it. However, in addition to the aforementioned concern (breaking system utilities) he now added the following comments: """ Also, from what I understand of python, when they roll out upgrades, there are somewhat unforgiving of backwards compatibility... What I don't want to happen is I roll out a new python (version of the month) and our support box is stuffed with - why did you upgrade it if it was working fine??? Now you have broken all my programs going from python 2.0 --> 2.1 --> 2.2 --> etc... This is what turns me off of tracking python, from a server administrators viewpoint... At least with Perl and PHP - they do everything possible to retain backwards compatibility... Perhaps this is all FUD, spread by the Perl and PHP camps... """ I responded, that it is essentially FUD. But, Python did recently release an upgrade that breaks old code (the whole division operator issue). Would someone like to respond to these concerns? I told the sysadmin that I would research this issue and report back. -- Sheila King http://www.thinkspot.net/sheila/ http://www.k12groups.org/

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Hiding the DOS console on a console application on Windows
by Eric Brunel Feb. 4, 2002

Feb. 4, 2002

Hi all, We've got a problem for which we were unable to find a solution: we have an Windows application that communicates with a console application and that needs to occasionally send it a Ctrl-Break. The only way we found to do that was to use the Windows function "GenerateConsoleCtrlEvent" via an extension module. Problem: this function only works if the parent and child processes share the same console, so our application has to be run or built as a console application. That means a start-up script with a .py extension (no .pyw, or it doesn't work), or a build without the option suppressing the console (e.g., no '--noconsole' option with Gordon McMillan's installer). However, our application has a GUI of its own, and we need to get rid of the DOS console that opens automatically when our script is run. Does anybody know a means to hide this console? We understand that this window has to be created, but we just don't want to see it... Our application uses Python 2.1.1 with a Tkinter GUI under Windows2k. TIA - eric -

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Defending the Python lanuage...
by rony.steelandt＠bucodi.com Feb. 4, 2002

Feb. 4, 2002

I din't answer all the answers one by one because they all make a point somehow ... but seem to miss my point. Perhaps i wasn't clear enough, this could be because english is not my native language. What i mean is that IMHO very often the wrong questions are aked here, or perhaps it depends of the job of the person who is asking the question. I myself i'm a manager of a software developping company, so i see these from a managment point of view. If, tomorrow, my chief software engineer comes to me and says "from now on i would like to use language X for our development", my questions would be : - Why ? What are the benefits and why should we change or add this language - What happens with the thousands of lines of code we wrote for our standard librarys and wich we are using for every project. And THIS is a very important question i think, because you're talking money here (sorry for the open source guys here <wink> ). If, as a company, you have to trow away a couple of thousand hours of investment because your development team wants to change you need a serious reason for this. And this goes even further than that, another point is how good will it be supported ? Here i don't mean only the language it self but allso his librarys. Take Python as an example. The language itself is going trough a *normal* growing cycle and is very well supported, but imaging that with version Python 3000 (:)the "community" has decided that the Tkinter library won't be supported any more.. I can assure you that this would be a very expensive decission for us, our whole GUI library is based on that now. And isn't this a risk with many open source projects ? - What will be the investment for training of our development team and how much time will it take - Do we have a 'small ' project we can use as a testcase and what do we have to do if we where wrong ?!! As i wanted to point out here there are a couple of other important questions that are very rarely asked here .... and who are IMHO more important as question but allso as answer and argument to use Python than the fact that you don't have to declare variables ... (as a stupid example)

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just another Tkinter installation problem
by heiko.wolf＠dlr.de Feb. 4, 2002

Feb. 4, 2002

Hi there, I know there are thousands of postings about this topic (I already read a lot), but they couldn't solve my problem... I hope that the people at comp.lang.python don't mind that I just post it ;) I'm using Python2.2 on Solaris 2.7... Now I wanted to add a small GUI to my prog, using Tkinter... Now I was told: if you want to use Tkinter, you'll need Tcl/Tk. So now I downloaded Tcl8.3.3 and Tk8.3.3. I installed everything that way: for Python: configure --prefix=/home/myhome/python then Tcl: configure --prefix=/home/myhome/tcl-tk make make install Tk: configure --prefix=/home/myhome/tcl-tk --with-tcl=/home/myhome/tcl_inst_dir/unix make make install no problems so far... Next step is editing the file "setup" in the Modules-subdirectory.. I simply changed the pathes there to the Tcl and Tk directory, I also did the other things recommended. but now when I want to do (again for Python): make I get the following message: ranlib libpython2.2.a gcc -o python \ Modules/python.o \ libpython2.2.a -lsocket -lnsl -ldl -lpthread -lthread -lm Undefined first referenced symbol in file init_tkinter libpython2.2.a(config.o) ld: fatal: Symbol referencing errors. No output written to python collect2: ld returned 1 exit status *** Error code 1 make: Fatal error: Command failed for target `python' Now, I tried to install again, but it ended up the same way.. Did I forget any important option at "configure" or something? I have to install all the files local, cause I've no rights on this system... Thanks in advance... Cheers, Heiko

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Re: Equivalent of Perl chomp?
by Steve Holden Feb. 4, 2002

Feb. 4, 2002

"Mark McEahern" <marklists(a)mceahern.com> wrote in message news:mailman.1012513005.17840.python-list@python.org... > Tim Peters wrote: > > Well, you're in for some fun of a kind I didn't have in mind <wink>. Do a > > sanity check here: what's the clock rate on your box? How many cycles go > > by in 0.07 seconds (let alone 0.36!)? Can you think of *any* > > non-insane way > > to implement these operations that would take so bloody long? > > > > [...] you might want to > > contemplate the sensibility of using a 100MB string. > > I admit to being perfectly clueless about these subtleties, which I'm sure > my code only demonstrated all too abundantly. ;-) > Indeed, but it also demonstrated you are the kind of person who can generate 100 MB strings without having to sit there and listen to the hardware wailing and gnashing its teeth, so I'm jealous already. Besides which, you show a laudable propensity to satisfy your curiosity by experiment, which makes a pleasant change from people asking questions they should be answering for themselves with web searches :-) Well done! > Anyway, switching the order and trying the test again only leads to further > confusion: > > <function sliceIt at 0x100f9510> : 0.00 seconds. > <function endsWith at 0x100f94d0> : 0.00 seconds. > > And, when I switch the order back, I get the same thing: > > <function endsWith at 0x100f94d0> : 0.00 seconds. > <function sliceIt at 0x100f9510> : 0.00 seconds. > So they both take exactly the same length of time, then? Perhaps not ... maybe you need a few more significant figures? > Is it: > > 1) That using time.time() for timing is brain dead? No, using time.time() is fairly well-accepted, with the proviso that its behavior in the large is much more reliable than its behavior in the small. On Windows, for example, the clock tends to tick around eighteen times a minute, so events timed naively can take either zero or about 50 milliseconds! So, it's usually a good idea to repeat your test many times, and average out the timings. > 2) I'm using an unrealistically large string? > Infeasibly for me and my little laptop, I'm afraid, , but the length of the string isn't really the point either. Your next exercise will be to see if it makes any difference... > Tim, is your point that the performance difference in normal cases is > negligible? If so, I would guess the further point would be to choose > endswith() because it's more legible. > I think Tim is pointing out that the things you are measuring had better happen in rather less than ten millliseconds if Python users aren't to take up cudgels and beat the development team to death with the floating-point unit from a Cray 1. From your latest timings the difference certainly appears negligible, but things are often not what they seem. Another thing to take into account is that testing invariably has to spend some time in "framework" code, whose duration should really be subtracted out if comparisons are to be meaningful. > I generally prefer the more legible approach and don't worry too much about > what's faster, but I thought I'd try to see whether these two different > approaches to endswith had a significant performance difference. > Here's a rewrite of your program (I added the comments after I got it working). #! /usr/bin/env python import time def getString(n): return "s" * n+ '\n' def endsWith(s): s.endswith('\n') def sliceIt(s): s[-1:] == '\n' # A "do nothing" for comparison def nullFunc(s): return s # Now we do a million tests, and average # the results for more sensible results def timeIt(func): n = 1000000 i = 1000000 s = getString(n) timeIn = time.time() for i in xrange(i): func(s) timeOut = time.time() return (timeOut - timeIn)/(i*1.0) # How long does it take to do nothing? nullTime = timeIt(nullFunc) # The reported times have the null time removed print "Endswith %1.8f" % (timeIt(endsWith)-nullTime) print "sliceIt %1.8f" % (timeIt(sliceIt)-nullTime) My results follow. You may find you need to add a couple more decimal places to get sensible results, my Thinkpad is a bit of a cronker ... D:\Steve\Projects\Python>python time1.py Endswith 0.00000511 sliceIt 0.00000434 D:\Steve\Projects\Python>python time1.py Endswith 0.00000511 sliceIt 0.00000186 D:\Steve\Projects\Python>python time1.py Endswith 0.00000505 sliceIt 0.00000209 As you can see there is still some variability but slicing looks like a clear winner. Increasing the iteration count might produce convergence on the timings. You might also ponder why sliceIt appear more variable than Endswith (tell me if you think of a good reason, I have no clue - this isn't a trick question). Tim actually dealt with you very kindly. Perhaps we were lucky he's busy. >From what I've been able to gather, in a former incarnation he was responsible for all kinds of hairy floating point stuff, and would go over his benchmark programs with a sharp chisel to shave off the last few microseconds. So he knows more about performance measurement than both of us put together. and-averaged-out-over-a-million-lifetimes-ly y'rs - steve -- Consulting, training, speaking: http://www.holdenweb.com/ Python Web Programming: http://pydish.holdenweb.com/pwp/

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