🌐 Mailman 3 September 2007 - Python-list - python.org

Re: list index()
by Steve Holden Sept. 1, 2007

Sept. 1, 2007

Dennis Lee Bieber wrote: > On Fri, 31 Aug 2007 21:15:10 +0100, DaveM <asma61(a)dsl.pipex.com> > declaimed the following in comp.lang.python: > > >> No - but I would pronounce "lever" and "fever" the same way, if that helps. >> > <shudder> To me, those are different... I suppose you also add an > extra "i" to aluminum <G> No, he just spells it with two i's like sensible people do. Who would ever want *three* I's in "aluminium" (which, by the way, you misspelled ;-)? Such things are matters of practical significance to me, since I have adopted a policy of using English spelling when in the UK and US spelling when elsewhere. Since I am now pretty much full-time in the US, I am finally having to come to terms with its crazy spelling. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --------------- Asciimercial ------------------ Get on the web: Blog, lens and tag the Internet Many services currently offer free registration ----------- Thank You for Reading -------------

1 0

HowTo Use Cython on a Windows XP Box?
by David Lees Sept. 1, 2007

Sept. 1, 2007

August 31, 2007 I just downloaded the current Cython release and have no problem running the cpython.py translator on the demo code. But when I try compiling, I get an error complaining that my version of Python (which is the current 2.5.1 downloaded from python.org) was compiled with Visual C++ 2003. I only have Visual C++ 2005 on my machine and am unable to find a download of 2003 on the Microsoft site (no big surprise). I have never built Python from source. Is it necessary or can someone suggest an alternative? TIA david lees

4 5

Re: status of Programming by Contract (PEP 316)?
by Russ Sept. 1, 2007

Sept. 1, 2007

On Aug 31, 6:45 pm, Steve Holden > We probably need to distinguish between "mission-critical", where a > program has to work reliably for an organization to meet its goals, and > "safety-critical" where people die or get hurt if the program misbehaves. The term "mission critical" itself can have a wide range of connotations. If a software failure would force a military pilot to abort his mission and hobble back home with a partially disabled aircraft, that's what I think of as "mission critical" software. If Google needs reliable software on its servers to maintain its revenue stream, that's another kind of "mission critical" software, but the criticality is certainly less immediate in that case. In the first case, the software glitch definitely causes mission failure. In the Google case, the software problems *may* ultimately cause mission failure, but probably only if nothing is done for quite some time to rectify the situation. If that is the case, then the software itself is not the critical factor unless it cannot be corrected and made to function properly in a reasonable amount of time.

1 0

Re: strings (dollar.cents) into floats
by Ben Finney Sept. 1, 2007

Sept. 1, 2007

luca bertini <luca.bertini(a)email.it> writes: > i have strings which look like money values (ie 34.45) > is there a way to convert them into float variables? You most likely do *not* want floating-point numbers for currency, since they rely on the operating system's binary floating point support which cannot accurately represent decimal fractions. >>> float("34.45") 34.450000000000003 Use the arbitrary-precision decimal.Decimal type instead. >>> from decimal import Decimal >>> Decimal("34.45") Decimal("34.45") They support the full range of arithmetic operations, without cumulative precision errors that floats are prone to. -- \ "As the evening sky faded from a salmon color to a sort of | `\ flint gray, I thought back to the salmon I caught that morning, | _o__) and how gray he was, and how I named him Flint." -- Jack Handey | Ben Finney

8 11

Automation and scheduling of front page publishing using python
by andrew.arobert＠gmail.com Sept. 1, 2007

Sept. 1, 2007

Good afternoon, We have numerous web sites which are currently being manually published via Front Page. Doing one or two sites on an ad-hoc basis was not too bad but we are now over 20 or thirty at set times during a business day. What I would love to do is find a way of automating this task, ideally by the command line, and called from a central automated task scheduler such as Maestro. Using Cygwin's rsync or Microsoft's Robocopy successfully moves a site from one file system path to another but the front page extensions and navigation/etc are broken. Does anyone know of an alternative method for handling this using Python? I did a google search and a scan of the cheese shop but nothing seems to jump out as a place to start. Any advice you can give on this would be fantastic. I've been trying to introduce Python to my shop for some time but they have been most resistant, usually insisting on Perl. Thanks, Andy

3 2

Parameter Passing - String Variable Truncated ?
by goldtech Sept. 1, 2007

Sept. 1, 2007

Hi, I'm passing what I think is a string parameter to another Python program (spawn.py) - see the code snip below. But only the counter part gets printed to a log file via spawn.py. Yet the echo print to the output window shows the whole string with the fc part. Better explained below I hope, there's the calling .py and the spawn script .py: ...snip... while fc: counter = counter + 1 fc_cntr = str(counter) + ' : ' + fc print fc_cntr + '\n' # Print to Pythonwin interactive window - eg. "1 : New York" - all is printed OK arglist = [] arglist.append(pythonPath) arglist.append(spawn_script) arglist.append(fc_cntr) # This gets sent to the spawn_script but only "1" gets printed os.spawnv(os.P_WAIT, pythonPath, arglist) fc = fcs.next() ... -------------------------- ## the spawn_script import win32com.client, sys, os, time, re in_featclass = sys.argv[1] handle = open('C:\\log_file.txt', 'a') handle.write(in_featclass + "\n") # ONLY the counter part gets printed to the log file! Why? -------------------------- Thanks, for help.

3 4

Python weather application
by seancron Sept. 1, 2007

Sept. 1, 2007

Does anybody have any suggestions for getting started on desigining a desktop weather application in Python? I've been looking for access to weather data and while I have found several including the weather.com service I've decided to use the Yahoo! Rss Weather feed since it doesn't have a license like the weather.com service does. However one problem I have with it is that it only accepts zip codes or locations ids. So if a user was to enter the name of the city instead of those two there would be an error. I could make it so they could only enter in the location code or zip code but I would really prefer to have it be automatically corrected. Does anyone have ideas on how to go about this or have an other suggestions? Thanks, Sean

3 2

Re: list index()
by Lawrence D'Oliveiro Sept. 1, 2007

Sept. 1, 2007

In message <mailman.156.1188498891.28954.python-list(a)python.org>, Carsten Haese wrote: > On Thu, 2007-08-30 at 11:21 -0700, zzbbaadd(a)aol.com wrote: > >> I wish they were not >> getting rid of dict.has_key() in Python 3, which I prefer to IN. > > That wish will only come true if you maintain your own fork of Python 3. > has_key() will go away, period. It has been made obsolete by "in", which > is faster and more concise. And is also a backdoor way of introducing non-virtual methods into Python, is it not.

2 1

Re: status of Programming by Contract (PEP 316)?
by Russ Sept. 1, 2007

Sept. 1, 2007

Ricardo Aráoz wrote: > Actually my point was that if a program is to be trusted in a critical > situation (critical as in catastrophe if it goes wrong) then the OS, the > compiler/interpreter etc should abide by the same rules. That is > obviously not possible, so there's not much case in making the time > investment necessary for correctness proof of a little program (or > usually a little function inside a program) when the possibilities for > failure are all around it and even in the code that will run that > function. And we should resort to other more sensible answers to the > safety problem. I don't quite see it that way. I would agree that if your OS and compiler are unreliable, then it doesn't make much sense to bend over backwards worrying about the reliability of your application. But for real safety-critical applications, you have no excuse for not using a highly reliable OS and compiler. For really critical stuff, I think the real-time OSs are usually stripped down to the bare basics. And if you are using something like SPARK Ada, the language itself is stripped of many of the fancier features in Ada itself. (There's also something called the Ada Ravenscar profile, which I believe is geared for safety-critical use but is not quite as restrictive as SPARK.) Keep in mind that the OS and compiler are typically also used for many other applications, so they tend to get tested fairly thoroughly. And remember also that you won't have extraneous applications running -- like a web browser or a video game, so the OS will probably not be heavily stressed. The most likely source of failure is likely to be your application, so bending over backwards to get it right makes sense. Then again, if you are running C on Windows, you might as well just give up on reliability from the start. You don't have a prayer.

1 0

Re: Python Unicode to String conversion
by John Machin Sept. 1, 2007

Sept. 1, 2007

On Sep 1, 9:56 am, "Chris Mellon" <arka...(a)gmail.com> wrote: > On 8/31/07, thijs.br...(a)gmail.com <thijs.br...(a)gmail.com> wrote: > > > Hi everyone, > > > I'm having quite some troubles trying to convert Unicode to String > > (for use in psycopg, which apparently doesn't know how to cope with > > unicode strings). > > > The error I keep having is something like this: > > ERREUR: Séquence d'octets invalide pour le codage «UTF8» : 0xe02063 > > > (sorry, locale is french, it means "byte sequence invalid for encoding > > <<utf8>>", the value is probably an e with one of the french accents) > > > I've found lots of stuff about this googling the error, but I don't > > seem to be able to find a "works always"-function just to convert a > > unicode variable back to string... > > encode(). > > You didn't post the code that was failing, I can encode that value > into UTF-8 What is "that value"? (1) unichr(0xe02063)? You must have a wide unicode build of Python ... (2) u"\xe0\x20\x63"? Of course you can encode it; so what? > (and unless I'm very much mistaken, you should be able to > encode any unicode string to UTF-8). That is true, by definition. However you are barking this truism up the wrong tree. The unknown complainant's whinge is that it is expecting a sequence of octets (an 8-bit string) that is valid UTF8, but the actuality is something else. It is *NOT* trying to say that a unicode input can't be converted to UTF8.

1 0