Mailman 3 March 2005 - Python-Dev

Change 'env var BROWSER override' semantics in webbrowser.py
by Rodrigo Dias Arruda Senra 28 Mar '05

28 Mar '05

Hi, I propose a small change in webbrowse.py module. At the present time: """ Under Unix, if the environment variable BROWSER exists, it is interpreted to override the platform default list of browsers,... """ (extract from Python-2.4/Doc/html/lib/module-webbrowser.html) I propose the following change: ''' --- webbrowser.py 2005-03-18 17:43:58.736854784 -0300 +++ webbrowser.py.new 2005-03-18 17:29:57.016815680 -0300 @@ -355,7 +355,7 @@ if "BROWSER" in os.environ: # It's the user's responsibility to register handlers for any unknown # browser referenced by this value, before calling open(). - _tryorder = os.environ["BROWSER"].split(os.pathsep) + _tryorder = os.environ["BROWSER"].split(os.pathsep) + _tryorder for cmd in _tryorder: if not cmd.lower() in _browsers: ''' This changes the semantics a bit, but in a positive way: - When the environment variable BROWSER is messed up, there is no reason not to try the other detected browser alternatives - If the BROWSER variable is Ok, than it is respected If nobody stand against it, or would like to propose an alternative (optimized) implementation, I can submit a patch to sf to alter both code and documentation. I'd appreciate to know if you consider this a bug or a new feature ? I consider this a bug: """ The webbrowser module provides a very high-level interface to allow displaying Web-based documents to users. The controller objects are easy to use and are platform-independent. Under most circumstances, simply calling the open() function from this module will do the right thing. """ (extract from Python-2.4/Doc/html/lib/module-webbrowser.html) Ignoring valid *already* detected browsers, due to a broken environment variable does not sound like _do the right thing_. <wink> cheers, Senra -- Rodrigo Senra MSc Computer Engineer rodsenra(a)gpr.com.br GPr Sistemas Ltda http://www.gpr.com.br

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Re: [Python-Dev] sum()
by Raymond Hettinger 28 Mar '05

28 Mar '05

[Alex] > > FWIW, when accuracy is an issue, I use: > > > > sum(sorted(data, key=abs)) > > ...and you may still lose a LOT of accuracy that way:-(. > > Raymond, you technically reviewed the 2nd ed Cookbook -- don't you > recall the sidebar about why partials are the RIGHT way to do > summations? I was SO proud of that one, thought I'd made the issue > clearest than anywhere previously in print... No doubt about it. Partials are superior. My little snippet meets my needs with no fuss -- my usual situation is many small values whose accuracy gets clobbered upon encountering a handful of large values. In the draft statistics module, nondist/sandbox/statistics/statistics.py , I used yet another approach and tracked a separate error term. The advantage is adding precision while still keeping O(n) summation speed. Of course, we can always use the decimal module to add as much precision as needed. Raymond

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Deprecating 2.2 old bugs
by Facundo Batista 28 Mar '05

28 Mar '05

Going on with the old bugs checking, here are the results for 2.2. When I'll finish this will be put in an informational PEP. When I verified the bug, I filled two fields: - Summary: the same subject as in SF - Group: the bug's group at verifying time. - Bug #: the bug number - Verified: is the date when I checked the bug. - Action: is what I did then. If the bug survived the verification, the next two fields are applicable (if not, I put a dash, the idea is to keep this info easily parseable): - Final: is the action took by someone who eliminated the bug from that category (closed, moved to Py2.4, etc). - By: is the someone who did the final action. So, here's the info... Summary: docs need to discuss // and __future__.division Group: 2.2 Bug #: 449093 Verified: 25-Nov-2004 Action: Deprecation alerted. Can't discern if it's really a bug or not. Final: Group changed to 2.4. By: facundobatista Summary: new int overflow handling needs docs Group: 2.2 Bug #: 454446 Verified: 25-Nov-2004 Action: Closed: Won't fix. Behaviour changed. Final: - By: - Summary: urllib2 proxyhandle won't work. Group: 2.2 Bug #: 487471 Verified: 25-Nov-2004 Action: Deprecation alerted. I can not try it, don't have that context. For a comment is not clear to me if it's a bug or not. Final: Closed: Won't fix. By: facundobatista Summary: BasHTTPServer IE Mac 5.1 size problem Group: 2.2 Bug #: 812340 Verified: 08-Nov-2004 Action: Deprecation alerted. I can not try it, don't have that context. Final: Closed: Won't fix. By: facundobatista Summary: Section 11.20: xmlrpclib Details Group: 2.2 Bug #: 791067 Verified: 11-Nov-2004 Action: Deprecation alerted. Doc changed a lot, don't know enough about the subject to be clear to me if the problem is solved or not. Final: Closed: Won't fix. By: facundobatista Summary: socket.inet_aton on 64bit platform Group: 2.2 Bug #: 767150 Verified: 11-Nov-2004 Action: Deprecation alerted. I can not try it, don't have that context. Final: Closed: Won't fix. By: facundobatista Summary: Error using Tkinter embeded in C++ Group: 2.2 Bug #: 699068 Verified: 11-Nov-2004 Action: Deprecation alerted. I can not try it, don't have that context. For a comment is not clear to me if the problem actually existed. Final: Closed: Won't fix. By: facundobatista Summary: raw_input defers alarm signal Group: 2.2 Bug #: 685846 Verified: 11-Nov-2004 Action: Changed to Group Py2.3, there's a patch: #706406 Final: - By: - Summary: repr.repr not always safe Group: 2.2 Bug #: 666958 Verified: 15-Nov-2004 Action: Changed to Group Py2.3: it seems a bug to me. Final: - By: - Summary: win32 os.path.normpath not correct for leading slash cases Group: 2.2 Bug #: 665336 Verified: 16-Nov-2004 Action: Changed to Group Py2.4: it seems a bug to me. Final: - By: - Summary: memory leaks when importing posix module Group: 2.2 Bug #: 613222 Verified: 21-Mar-2005 Action: Changed to Group Py2.3, considering original post. Final: - By: - Summary: xml.sax second time file loading problem Group: 2.2 Bug #: 606692 Verified: 15-Nov-2004 Action: Deprecation alerted. Final: Closed: Won't fix. By: facundobatista Summary: urllib ftp broken if Win32 proxy Group: 2.2 Bug #: 532007 Verified: 15-Nov-2004 Action: Deprecation alerted. Final: Closed: Won't fix. By: facundobatista Summary: Bugs in rfc822.parseaddr() Group: 2.2 Bug #: 531205 Verified: 24-Nov-2004 Action: Changed to Group Py2.4: it seems a bug to me. Final: Closed. Invalid. By: loewis Summary: shelve update fails on "large"; entry Group: 2.2 Bug #: 523425 Verified: 25-Nov-2004 Action: Deprecation alerted. Can't discern if it's really a bug or not. Final: Closed: Fixed (the original submitter posted that is fixed in later version) By: facundobatista Summary: exception cannot be new-style class Group: 2.2 Bug #: 518846 Verified: 24-Nov-2004 Action: Changed to Group Py2.3: it seems a bug to me. Final: - By: - Summary: Missing docs for module imputil Group: 2.2 Bug #: 515751 Verified: 25-Nov-2004 Action: Changed to Group Py2.4: it seems a bug to me. Final: - By: - Regards, . Facundo Blog: http://www.taniquetil.com.ar/plog/ PyAr: http://pyar.decode.com.ar/

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A bunch of patch reviews
by Michiel Jan Laurens de Hoon 27 Mar '05

27 Mar '05

Below are a set of five patch reviews. I don't have any patch to push for at this point, so these patch reviews are just for you to read and enjoy. Thanks everybody for developing and maintaining Python. I wouldn't know what to do without it. --Michiel. Patch [ 853890 ] Optional keyword unicode args not handled correctly The skipitem function in Python/getargs.c misses code for several argument formats. This patch solves one of them ('u' and 'u#'), patch 985713 solves another one ('w'). There are several more that need to be solved. I've asked the patch contributor to write a complete patch, including all missing formats. This patch is rather straightforward and solves a serious problem, so I'd recommend accepting it once it is complete. Patch [ 1167316 ] a fix for doctest crash when it is ran on itself doctest.py in Lib fails when it is run on itself. The error is due to missing "import doctest" statements and similar small problems in the doctest docstrings. Patch seems to work correctly. Patch [ 1166780 ] Fix _tryorder in webbrowser.py In webbrowser.py, a user can override the default list of web browsers to be opened by setting the BROWSER variable. Currently, if BROWSER is set, the default list is not used at all. The patch contributor notes that if BROWSER is set incorrectly, this may result in no browser being opened at all. While this is true, seeing a different browser open instead of the one specified in BROWSER may lead to confusion, and may lead to future bug reports saying "webbrowser.py ignores the BROWSER variable" if a user sets BROWSER incorrectly. So my suggestion is to at least print a warning message if the browser specified in BROWSER cannot be used, and then proceed by opening one of the default browsers. Patch [ 764221 ] add set/getattr interface to tkFont.Font objects This patch has already made it into Python2.4, so I think this patch can be closed. Patch [ 1163314 ] the quotes page on the Web site links to something broken The patch writer is correct that the link is broken, but it's not a Python bug. I've suggested him to write to the web master. -- Michiel de Hoon, Assistant Professor University of Tokyo, Institute of Medical Science Human Genome Center 4-6-1 Shirokane-dai, Minato-ku Tokyo 108-8639 Japan http://bonsai.ims.u-tokyo.ac.jp/~mdehoon

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FYI: news items about Burton Report on P-languages
by Guido van Rossum 26 Mar '05

26 Mar '05

---------- Forwarded message ---------- From: Google Alerts <googlealerts-noreply(a)google.com> Date: Fri, 25 Mar 2005 15:36:32 -0800 (PST) Subject: Google Alert - python -spamalot -monty To: gvanrossum(a)gmail.com Google Alert for: python -spamalot -monty Report: P-Languages Better For Enterprise InternetNews.com - USA PHP (define), Perl (define), and Python (define) (the P-Languages) have really come into their own over the last four or five years because of their ability to ... See all stories on this topic Perl, Python and PHP get the nod for Enterprise. HTML FIX IT.COM - Grand Rapids,MI,USA Perl Python and PHP are all Open Source programming languages and there is a ton of free software written in all of those languages available online. ... Report: P-Languages Better For Enterprise (InternetNews) ACM Queue - New York,NY,USA PHP, Perl and Python are mission-critical ready and more effective than C++, Java, and C# in some scripting scenarios, according to Burton Group. ... ________________________________ This once a day Google Alert is brought to you by Google. Remove this alert. Create another alert. Manage your alerts. -- --Guido van Rossum (home page: http://www.python.org/~guido/)

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tree data structure and python
by vivek khurana 26 Mar '05

26 Mar '05

Hi! all i am a new member on this list. I have to implement tree data structure using python. How it can be done in python. Is there an existing data structure which can be used as tree? I have searched archives and manuals but no luck. Regards VK Hug the REALITY ;-) Disclaimer The facts expressed here belong to everybody, the opinions to me. The distinction is yours to draw... __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/

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Using descriptors to dynamically attach methods written in Python to C-defined (new-style) types
by Travis Oliphant 26 Mar '05

26 Mar '05

In updating Numeric to take advantage of the new features in Python, I've come across the need to attach a Python-written function as a method to a C-builtin. I don't want to inherit, I just want to extend the methods of a builtin type using a Python function. I was thinking of updating the new type objects dictionary with a new entry that is a descriptor object. It seems that the descriptor mechanism makes this a relatively straightforward thing. My question is, can I use the already-available Descriptor objects to do this, or will I need to define another Descriptor object. (Perhaps a PythonMethod descriptor object to complement the Method Descriptor). Any hints will be helpful. -Travis Oliphant

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C API for the bool type?
by Bo Thorsen 24 Mar '05

24 Mar '05

Hi people, If this is not the correct place to post this problem, I apologize. In that case, please be gentle and point me to a better mailing list. I'm coding a text editor in Qt that uses Python for macros. The problem I have is that want to use the bool type introduced in 2.3, but I can't see how to do this. On http://docs.python.org/api/arg-parsing.html the format units are described, but no bool is there. I guess there are two possibilities. Either the documentation is not updated with the new format unit, or it doesn't exist. If it doesn't exist, I guess I should use the int format unit and call the http://docs.python.org/api/boolObjects.html functions to see if this is actually a bool or not? I hope you can help me with this question. Please CC me with answers, since I am not a member of this list. Thanks, Bo Thorsen. -- Thorsen Consulting ApS - Qt programming services http://www.thorsen-consulting.dk

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Shorthand for lambda
by Ka-Ping Yee 24 Mar '05

24 Mar '05

Hey folks, I'm sitting over here in the AppleScript talk and Jacob is explaining a module called 'appscript' that interfaces to the Apple Events system. What caught my eye was this example: from appscript import * ab = app('Address Book') people = ab.people.filter(its.emails != []) That last line asks the Address Book to select only entries with e-mail addresses. The weird 'its' object comes from the appscript module -- asking for its properties and using operators causes it to set up thunks for you. It dawned on me that you could use this idea to make the whole filter/lambda experience vastly more pleasant. I whipped up a quick implementation: >>> from placeholder import _ >>> numbers = [5, 9, 56, 34, 1, 24, 37, 89] >>> filter(_ < 30, numbers) [5, 9, 1, 24] >>> map(_ + 10, numbers) [15, 19, 66, 44, 11, 34, 47, 99] >>> Look ma, no lambdas! I bet someone has already done this before, right? -- ?!ng

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webbrowser.py: browser >/dev/null 2>&1
by Oleg Broytmann 24 Mar '05

24 Mar '05

Hello! While I'm working on webbrowser... Why do all graphical browsers are called with their stdout/stderr redirected to /dev/null? Do we really need to hide problems from the user? Browsers are usually silent beasts - they interact with the user using windows, not stdio. (Text-mode browsers, naturally, use stdout... for their windows). I'd like to remove all those redirects. Any opinion? Oleg. -- Oleg Broytmann http://phd.pp.ru/ phd(a)phd.pp.ru Programmers don't die, they just GOSUB without RETURN.

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