web2py 1.40 is out
web2py 1.40 is out A web2py book is out too: http://he-cda.wiley.com/WileyCDA/Section/id-321954.html Here is a sample: http://mdp.cti.depaul.edu/examples/static/web2py_manual_cut.pdf Here are some videos: http://www.vimeo.com/videos/search:web2py version 1.40 includes: - Database Abstraction Layer for SQLite, MySQL, PostgreSQL, MSSQL, FireBird, Oracle, and the Google App Engine. - More handlers for wsgi, fastcgi, mod_python and cgi (for the google app engine). - Setup scripts for production deployment. SUPER EASY === Here is an example of a complete minimalist web app: def index(): return Hello World Here is an example of a complete minimalist web app with a counter: def index(): session.counter=session.counter+1 if session.counter else 1 return dict(counter=session.counter) EXPRESSIVE === Here is an example of a complete app that asks your name and greats you with an AJAX flash message: def index(): form=FORM(INPUT(_name='your_name',requires=IS_NOT_EMPTY ()),INPUT(_type='submit')) if form.accepts(request.vars): response.flash='Hello '+form.vars.your_name return dict(form=form) POWERFUL == Here is an example of a complex query (nested select): rows=db(db.table1.field1.belongs(db()._select (db.table2.field2)).select(orderby=db.table1.field2,limitby=(10,20)) a left join: rows=db().select(db.table1.ALL,db.table2.ALL,left=db.table2.on (db.table1.field1==db.table2.field2)) Have fun! Massimo -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: max(), sum(), next()
On Sep 4, 12:20�am, Mensanator [EMAIL PROTECTED] wrote: On Sep 3, 8:30 pm, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Wed, 03 Sep 2008 16:20:39 -0700, Mensanator wrote: sum([]) 0 is a bug, just as it's a bug in Excel to evaluate blank cells as 0. It should return None or throw an exception like sum([None,1]) does. You're wrong, because 99.9% of the time when users leave a blank cell in Excel, they want it to be treated as zero. Then 99.9% of users want the wrong thing. Microsoft knows that this is a bug but refuses to fix it to prevent breaking legacy documents (probably dating back to VisiCalc). When graphimg data, a missing value should be interpreted as a hole in the graph +--+ � � � � � � +--+--+--+-+ and not evaluated as 0 +--+ � � � � � � +--+--+--+-+ � � � � \ � � � � � / � � � � �\ � � � � / � � � � � \ � � � / � � � � � �\ � � / � � � � � � \ � / � � � � � � �\+/ (depending on the context of the graph, of course). And Microsoft provides a workaround for graphs to make 0's appear as holes. Of course, this will cause legitimate 0 values to disappear, so the workaround is inconsistent. I just checked and I mis-remembered how this works. The option is for blanks to plot as holes or 0 or be interpolated. 0 always plots as 0. The inconsistency is that blanks are still evaluated as 0 in formulae and macros. Spreadsheet sum() is not the same as mathematician's sum, which doesn't have a concept of blank cells. (But if it did, it would treat them as zero, since that's the only useful thing and mathematicians are just as much pragmatists as spreadsheet users.) The Excel code does the right thing, and your pure solution would do the unwanted and unexpected thing and is therefore buggy. Apparently, you don't use databases or make surface contours. Contour programs REQUIRE that blanks are null, not 0, so that the Kriging algorithm interpolates around the holes rather than return false calculations. Excel's treatment of blank cells is inconsistent with Access' treatment of Nulls and therefore wrong, anyway you slice it. Math isn't a democracy, what most people want is irrelevant. I don't pull these things out of my ass, it's real world stuff I observe when I help CAD operators and such debug problems. Maybe you want to say a bug is when it doesn't do what the author intended, but I say if what the intention was is wrong, then a perfect implentation is still a bug because it doesn't do what it's supposed to do. Bugs are defined by does the code do what the user wants it to do?, not is it mathematically pure?. ReallY? So you think math IS a democracy? There is no reason to violate mathematical purity. If I don't get EXACTLY the same answer from Excel, Access, Mathematica and Python, then SOMEBODY is wrong. It would be a shame if that somebody was Python. The current behaviour of sum([]) does the right thing for the 99% of the time when users expect an integer. Why shouldn't the users expect an exception? Isn't that why we have try:except? Maybr 99% of users expect sum([])==0, but _I_ expect to be able to distinguish an empty list from [4,-4]. And the rest of the time, they have to specify a starting value for the sum anyway, and so sum([], initial_value) does the right thing *always*. So if you really want [] to be 0, why not say sum([],0)? Why shouldn't nothing added to nothing return nothing? Having it evaluate to 0 is wrong 99.9% of the time. The only time it does the wrong thing[1] is when you forget to pass an initial value but expect a non-numeric result. And that's the programmer's error, not a function bug. [1] I believe it also does the wrong thing by refusing to sum strings, but that's another story. -- Steven- Hide quoted text - - Show quoted text - -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
Mensanator wrote: No it isn't. Nothing is not 0, check with MS-Access, for instance: Null + 1 returns Null. Any arithmetic expression involving a Null evaluates to Null. Adding something to an unknown returns an unknown, as it should. It is a logical fallacy to equate unknown with 0. http://en.wikipedia.org/wiki/Empty_sum In mathematics, the empty sum, or nullary sum, is the result of adding no numbers, in summation for example. Its numerical value is zero. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Wed, 03 Sep 2008 22:20:43 -0700, Mensanator wrote: On Sep 3, 8:30�pm, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Wed, 03 Sep 2008 16:20:39 -0700, Mensanator wrote: sum([]) 0 is a bug, just as it's a bug in Excel to evaluate blank cells as 0. It should return None or throw an exception like sum([None,1]) does. You're wrong, because 99.9% of the time when users leave a blank cell in Excel, they want it to be treated as zero. Then 99.9% of users want the wrong thing. It is to laugh. Microsoft knows that this is a bug Says you. but refuses to fix it to prevent breaking legacy documents (probably dating back to VisiCalc). When graphimg data, a missing value should be interpreted as a hole in the graph Graphing data is not sum(). I don't expect graphing data to result in the same result as sum(), why would I expect them to interpret input the same way? +--+ +--+--+--+-+ Why should the graphing application ignore blanks (missing data), but sum() treat missing data as an error? That makes no sense at all. and not evaluated as 0 And Microsoft provides a workaround for graphs to make 0's appear as holes. Of course, this will cause legitimate 0 values to disappear, so the workaround is inconsistent. I'm not aware of any spreadsheet that treats empty cells as zero for the purpose of graphing, and I find your claim that Excel can't draw graphs with zero in them implausible, but I don't have a copy of Excel to test it. Spreadsheet sum() is not the same as mathematician's sum, which doesn't have a concept of blank cells. (But if it did, it would treat them as zero, since that's the only useful thing and mathematicians are just as much pragmatists as spreadsheet users.) The Excel code does the right thing, and your pure solution would do the unwanted and unexpected thing and is therefore buggy. Apparently, you don't use databases or make surface contours. Neither databases nor surface contours are sum(). What possible relevance are they to the question of what sum() should do? Do you perhaps imagine that there is only ONE POSSIBLE CORRECT WAY to deal with missing data, and every function and program must deal with it the same way? Contour programs REQUIRE that blanks are null, not 0 Lucky for them that null is not 0 then. so that the Kriging algorithm interpolates around the holes rather than return false calculations. Excel's treatment of blank cells is inconsistent with Access' treatment of Nulls and therefore wrong, anyway you slice it. No no no, you messed that sentence up. What you *really* meant was: Access' treatment of Nulls is inconsistent with Excel's treatment of blank cells and therefore wrong, anyway you slice it. No of course not. That would be stupid, just as stupid as your sentence. Excel is not Access. They do different things. Why should they necessarily interpret data the same way? Maybe you want to say a bug is when it doesn't do what the author intended, but I say if what the intention was is wrong, then a perfect implentation is still a bug because it doesn't do what it's supposed to do. Who decides what it is supposed to do if not the author? You, in your ivory tower who doesn't care a fig for what people want the software to do? Bug report: Software does what users want it to do. Fix: Make the software do something that users don't want. Great. Bugs are defined by does the code do what the user wants it to do?, not is it mathematically pure?. ReallY? So you think math IS a democracy? There is no reason to violate mathematical purity. You've given a good example yourself: the Kriging algorithm needs a Null value which is not zero. There is no mathematical null which is distinct from zero, so there's an excellent violation of mathematical purity right there. If I am given the job of adding up the number of widgets inside a box, and the box is empty, I answer that there are 0 widgets inside it. If I were to follow your advice and declare that An error occurred, can't determine the number of widgets inside an empty box! people would treat me as an idiot, and rightly so. If I don't get EXACTLY the same answer from Excel, Access, Mathematica and Python, then SOMEBODY is wrong. It would be a shame if that somebody was Python. Well Excel, Python agree that the sum of an empty list is 0. What do Access and Mathematica do? The current behaviour of sum([]) does the right thing for the 99% of the time when users expect an integer. Why shouldn't the users expect an exception? Isn't that why we have try:except? Maybr 99% of users expect sum([])==0, but _I_ expect to be able to distinguish an empty list from [4,-4]. The way to distinguish lists is NOT to add them up and compare the sums: sum([4, -4]) == sum([0]) == sum([1, 2, 3, -6]) == sum([-1, 2, -1]) True The correct way is by comparing the lists themselves: [] == [4, -4]
Re: Coming from .NET and VB and C
2008/9/3 Dennis Lee Bieber [EMAIL PROTECTED]: non-relational DBMS (if any such are still in use), There certainly are... SO, I'm interested in using my Google App space (free 500MB) to develop a quick database application. Using Python. I found Dive Into Python which I will be reading shortly. So one question: what RDBMs are supported in that space? ... and the Google's BigTable (see http://en.wikipedia.org/wiki/BigTable) is one of them. -- Cheers, Simon B. -- http://mail.python.org/mailman/listinfo/python-list
Re: python/xpath question..
Hi, you should really read about XPath. There are also newsgroups specifically for this topic, please use them. bruce wrote: in my python, i'm using the xpath function to iterate/parse some html. i can do something like s=d.xpath(//tr/td/text()) count=len(s) and get the number of nodes that have text That is a wrong assumption. It will give you the number of text nodes, not the number of elements. They may or may not be the same. i can then do something like s=d.xpath(//tr/td) count2=len(s) and get the number of total nodes... by subtracting, i can get the number of nodes, without text.. is there an easier way??!! Yes, learn to use XPath, e.g. //tr/td[not string()] Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: xml + mmap cross
castironpi wrote: Any interest in pursuing/developing/working together on a mmaped-xml class? Faster, not readable in text editor. Any hints on what you are talking about? Stefan -- http://mail.python.org/mailman/listinfo/python-list
use str as variable name
Hi, I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value rather than : if arg == 'height': a.height = new_value elif arg == 'width'; a.width = new_value Can I do this with python ? How ? Thanks, Mathieu -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
On Thu, Sep 4, 2008 at 12:25 AM, Mathieu Prevot [EMAIL PROTECTED] wrote: Hi, I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): You should subclass 'object', so that should be: class Foo(object): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value You're looking for the setattr() built-in function. In this exact case: setattr(a, arg, new_value) This is probably covered in the Python tutorial, please read it. Regards, Chris rather than : if arg == 'height': a.height = new_value elif arg == 'width'; a.width = new_value Can I do this with python ? How ? Thanks, Mathieu -- http://mail.python.org/mailman/listinfo/python-list -- Follow the path of the Iguana... http://rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
Mathieu Prevot wrote: I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value rather than : if arg == 'height': a.height = new_value elif arg == 'width'; a.width = new_value Can I do this with python ? How ? assuming you mean instance variable (a is an instance of the class foo), you can use setattr: a = foo() arg = 'height' setattr(a, arg, new_value) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
En Thu, 04 Sep 2008 04:25:37 -0300, Mathieu Prevot [EMAIL PROTECTED] escribi�: I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value rather than : if arg == 'height': a.height = new_value elif arg == 'width'; a.width = new_value You're looking for setattr: setattr(a, arg, new_value) http://docs.python.org/lib/built-in-funcs.html#l2h-66 Can I do this with python ? How ? Thanks, Mathieu -- http://mail.python.org/mailman/listinfo/python-list -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
2008/9/4 Chris Rebert [EMAIL PROTECTED]: On Thu, Sep 4, 2008 at 12:25 AM, Mathieu Prevot [EMAIL PROTECTED] wrote: Hi, I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): You should subclass 'object', so that should be: class Foo(object): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value You're looking for the setattr() built-in function. In this exact case: setattr(a, arg, new_value) This is probably covered in the Python tutorial, please read it. Regards, Chris Indeed. I'll use: a.__setattr__(height, new_value) Thanks to all Mathieu -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
Mathieu Prevot wrote: I'll use: a.__setattr__(height, new_value) that's an implementation detail. please use setattr() instead, like everyone else. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Late initialization using __getattribute__
bukzor a écrit : On Sep 3, 1:02 pm, Bruno Desthuilliers [EMAIL PROTECTED] wrote: bukzor a écrit : (snip) Thanks for the reply. Just to see it not work, I tried to remove __getattribute__ from LateInitMixIn, but couldn't get it to work. ??? Sorry, I don't get what you mean... Since you said __getattribute__ is an attribute of the class, I tried to run (something to the effect of) delattr(self.__class__, __getattribute__), Ah, ok. Definitively *not* a thing to do... but it threw an AttributeError. You'd have to call it on the mixin class itself, not on a subclass. My Base class is a C class (_mysql.connection from MySQLdb) that sometimes segfaults if you try to use it before it's fully initialized, ... I have used MySQLdb for years on more than a dozen linux distribs, and never had such a problem. Is this a known bug ? Or is there something wrong with your setup ? I'm trying to optimize my number of connections Connection pooling anyone ? IIRC, this is something that already exists in quite a couple libs / frameworks. Is there a reason you try to roll your own ? by not fully initializing (read: not connecting) my connection until it's used in some way. Of course the maintainer didn't envision this (mis)use, so the object sometimes throws bad errors until it's fully initialized. Ok. Of course the *correct* way to do this is to be more careful about when I create connections, but I think I should be able to get this to work, and it (would be) much easier to do it The Right Way once it works. Please pardon me for repeating the same thing over and over, but messing with __getattribute__ is certainly not the way to go. so unfortunately I think I need to use __getattribute__ to do this. I'm doing all this just to make the connection not actually connect until used. I may be dumb, but I don't get how this is supposed to solve your problem. But anyway : there's a known design pattern for what you're trying to do, that doesn't require mixins nor messing with __getattribute__ (which, I repeat, is more often than not something you *don't* want to do). The name of the design pattern is proxy. I strongly suggest that you 1/ try to cure the real problem instead of hacking around and 2/ read about the proxy design pattern. My 2 cents... I like the idea of mix-ins, but can't figure out how to make a proxy work that way. You mean, how to use a proxy for lazy initialization ? Heck, that's the exact use case in the GoF. For a long time I had a proxy class that added five or six features on top of the MySQLdb package, but it wasn't configurable enough, and I'm working on splitting each feature into its own MixIn class. As an aside, this is working for me pretty well. The reconnect method (inheritied from a Reconnectable mixin) uses several of the object's attributes, so I need to set _inited beforehand so that I don't get into an infinite __getattribute__ loop. What I'd *really* like to do is remove __getattribute__ from the object at that point. You can't. Or, more exactly, all you can do is remove __getattribute__ from the mixin class - but then the mixin class won't work anymore. I don't mean to be condescendant, but it looks like you don't have a clear understanding of Python's object model here - else you wouldn't even consider doing such a thing. FWIW, I posted a solution based on the __getattr__ hook, which did work - at least for the specs implied by your code snippet. -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 4, 1:26 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Wed, 03 Sep 2008 22:20:43 -0700, Mensanator wrote: On Sep 3, 8:30 pm, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Wed, 03 Sep 2008 16:20:39 -0700, Mensanator wrote: sum([]) 0 is a bug, just as it's a bug in Excel to evaluate blank cells as 0. It should return None or throw an exception like sum([None,1]) does. You're wrong, because 99.9% of the time when users leave a blank cell in Excel, they want it to be treated as zero. Then 99.9% of users want the wrong thing. It is to laugh. Microsoft knows that this is a bug Says you. but refuses to fix it to prevent breaking legacy documents (probably dating back to VisiCalc). When graphimg data, a missing value should be interpreted as a hole in the graph Graphing data is not sum(). I don't expect graphing data to result in the same result as sum(), why would I expect them to interpret input the same way? +--+ +--+--+--+-+ Why should the graphing application ignore blanks (missing data), but sum() treat missing data as an error? That makes no sense at all. Maybe it's important to know data is missing. You can see the holes in a graph. You can't see the holes in a sum. and not evaluated as 0 And Microsoft provides a workaround for graphs to make 0's appear as holes. Of course, this will cause legitimate 0 values to disappear, so the workaround is inconsistent. I'm not aware of any spreadsheet that treats empty cells as zero for the purpose of graphing, and I find your claim that Excel can't draw graphs with zero in them implausible, but I don't have a copy of Excel to test it. That was a mistake. I made a followup correction, but you probably didn't see it. Spreadsheet sum() is not the same as mathematician's sum, which doesn't have a concept of blank cells. (But if it did, it would treat them as zero, since that's the only useful thing and mathematicians are just as much pragmatists as spreadsheet users.) The Excel code does the right thing, and your pure solution would do the unwanted and unexpected thing and is therefore buggy. Apparently, you don't use databases or make surface contours. Neither databases nor surface contours are sum(). What possible relevance are they to the question of what sum() should do? Because a sum that includes Nulls isn't valid. If you treated Nulls as 0, then not only would your sum be wrong, but so would your count and the average based on those. Now you can EXPLICITLY tell the database to only consider non-Null values, which doesn't change the total, but DOES change the count. Do you perhaps imagine that there is only ONE POSSIBLE CORRECT WAY to deal with missing data, and every function and program must deal with it the same way? But that's what sum() is doing now, treating sum([]) the same as sum([],0). Why isn't sum() defined such that ...if list is empty, return start, IF SPECIFIED, otherwise raise exception. Then, instead of ONE POSSIBLE CORRECT WAY, the user could specify whether he wants Excel compatible behaviour or Access compatible behaviour. Contour programs REQUIRE that blanks are null, not 0 Lucky for them that null is not 0 then. No, but blank cells are 0 as far as Excel is concerned. That behaviour causes nothing but trouble and I am saddened to see Python emulate such nonsense. so that the Kriging algorithm interpolates around the holes rather than return false calculations. Excel's treatment of blank cells is inconsistent with Access' treatment of Nulls and therefore wrong, anyway you slice it. No no no, you messed that sentence up. What you *really* meant was: Access' treatment of Nulls is inconsistent with Excel's treatment of blank cells and therefore wrong, anyway you slice it. No of course not. That would be stupid, just as stupid as your sentence. Excel is not Access. They do different things. Why should they necessarily interpret data the same way? Because you want consistent results? Maybe you want to say a bug is when it doesn't do what the author intended, but I say if what the intention was is wrong, then a perfect implentation is still a bug because it doesn't do what it's supposed to do. Who decides what it is supposed to do if not the author? The author can't change math on a whim. You, in your ivory tower who doesn't care a fig for what people want the software to do? True, I could care less what peole want to do... ...as long as they do it consistently. Bug report: Software does what users want it to do. Fix: Make the software do something that users don't want. What the users want doesn't carry any weight with respect to what the database wants. The user must conform to the needs of the database because the other way ain't ever gonna happen. Great. If only. But then, I probably wouldn't have a job. Bugs are defined
Re: PyGUI as a standard GUI API for Python?
On 2008-09-04 07:49, Kay Schluehr wrote: 3) Following the public rumor mill and the latest hype RIA i.e. the merge of web- and desktop applications with systems like Adobe AIR, JavaFX, Google Gears and MS Silverlight is the future of frontend development. With the exception of IronPython and Silverlight, Python hasn't even entered this game and no one knows if it ever will. Actually, it has already and quite some time ago: http://www.artima.com/weblogs/viewpost.jsp?thread=208528 The recipe is simple: use Python for the business logic, database interfacing, etc and have it talk to a Flex front-end via XML-RPC or REST. As a nice side-effect, this also results in a better separation between GUI and backend, effectively making the solution future-proof and easy to adapt to other front-end technologies. We've been working with this approach for almost a year now and so far never had to look back. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Sep 04 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
Mathieu Prevot a écrit : 2008/9/4 Chris Rebert [EMAIL PROTECTED]: (snip) You're looking for the setattr() built-in function. In this exact case: setattr(a, arg, new_value) This is probably covered in the Python tutorial, please read it. Regards, Chris Indeed. I'll use: a.__setattr__(height, new_value) Please don't. Use the generic setattr() function instead. This holds for any __magic__ method : they are *implementation* for operators and generic functions - which you can think of as operators with a function syntax -, and are not meant to be called directly. You wouldn't write something like 2.__add__(3), would you ? -- http://mail.python.org/mailman/listinfo/python-list
CREDIT CARD DEPT
CREDIT CARD DEPT http://creditcarddept.googlepages.com -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
Mathieu Prevot [EMAIL PROTECTED] wrote: Hi, I have a program that take a word as argument, and I would like to link this word to a class variable. eg. class foo(): width = 10 height = 20 a=foo() arg='height' a.__argname__= new_value Not quite sure what the above is supposed to achieve rather than : if arg == 'height': a.height = new_value elif arg == 'width'; a.width = new_value Can I do this with python ? How ? setattr(a, arg, new_value) See: http://docs.python.org/lib/built-in-funcs.html -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
Bruno Desthuilliers wrote: You wouldn't write something like 2.__add__(3), would you ? Don't give the it's only OO if I write obj.method(args) crowd more bad ideas, please ;-) (...as Bruno implies, setattr(), len() et al can be and should be viewed as generic functions. A specific Python implementation may use custom code to implement behaviour for a given object; behaviour that's more efficient than a full Python-level method call. For example, in CPython, len(L) is about twice as fast as L.__len__() for built-in sequences.) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: PyGUI as a standard GUI API for Python?
On 4 Sep., 10:31, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 07:49, Kay Schluehr wrote: 3) Following the public rumor mill and the latest hype RIA i.e. the merge of web- and desktop applications with systems like Adobe AIR, JavaFX, Google Gears and MS Silverlight is the future of frontend development. With the exception of IronPython and Silverlight, Python hasn't even entered this game and no one knows if it ever will. Actually, it has already and quite some time ago: http://www.artima.com/weblogs/viewpost.jsp?thread=208528 The recipe is simple: use Python for the business logic, database interfacing, etc and have it talk to a Flex front-end via XML-RPC or REST. Python is still server-side in this scenario and plays no role in UI definitions. So one doesn't get more than e.g. Django apps that respond to HTTP requests triggered by JavaScript forms except that JavaScript+HTML+Browser is replaced by Flex = AS3+MXML+FlashPlayer. The role of Python is somewhat arbitrary. This could change only if Python becomes a client side language executed by AVM, V8 etc. like IronPython in Silverlight. About separating UI from application logics by assigning functionality to different general purpose languages I have to admit that I don't think it is such a great idea ... -- http://mail.python.org/mailman/listinfo/python-list
Re: How to write verbose scripts
On Tue, 02 Sep 2008 13:07:33 -0400, Joe Riopel wrote: On Tue, Sep 2, 2008 at 12:55 PM, Steven D'Aprano [EMAIL PROTECTED] wrote: Is there a better way of doing this than the way I am going about it? Would the logging module help, and just print the output to the stdout (or a file) instead? Thank you to everyone who answered. As I feared, it seems that there's no really simple way of dealing with arbitrary messages at arbitrary parts of my code. I'm currently playing around with a few ideas, one of which is a decorator to print information about function calls. However, what I'd like to avoid is having to explicitly call the decorator on every method. I guess that there's metaclass trickery I can play. Does anyone have any pointers on how I can apply a decorator to every method in a class automatically? -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Numeric literal syntax
Steven D'Aprano [EMAIL PROTECTED] writes: On Thu, 04 Sep 2008 01:22:22 +0100, Alexander Schmolck wrote: It seems to me that the right choice for thousands seperator is the apostrophe. You mean the character already used as a string delimiter? Yup. No ambiguity or problem here; indeed unlike space seperation or '_' it would work straighforwardly as a syntax extension in pretty much any programming language I can think as well as end-user output (I think that writing e.g. 1'000'000 on a website would be perfectly acceptable; unlike 1_000_000). 'as -- http://mail.python.org/mailman/listinfo/python-list
guenstige kredite
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guenstige kredite
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Re: Numeric literal syntax
[EMAIL PROTECTED] writes: A problem is that '1234' in Python is a string, so using ' in numbers looks a bit dangerous to me (and my editor will color those numbers as alternated strings, I think). Yeah, editors, especially those with crummy syntax highlighting (like emacs) might get it wrong. This should be easy enough to fix though. Indeed unlike raw and tripplequoted strings which were adopted without major hitches this new syntax wouldn't have any bearing on what's a valid string. 'as -- http://mail.python.org/mailman/listinfo/python-list
overwrite set behavior
Hi all, I want to modify the method that set use for see if there is already an object inside its obj-list. Something like this: class foo: pass bar1 = foo() bar1.attr = 1 bar2 = foo() bar2.attr = 1 set( (bar1, bar2), key=lambda o: o.attr) and, of course, set has only one value. It's possible? Thanks, Michele -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
On Thu, 04 Sep 2008 11:48:18 +0200, Michele Petrazzo wrote: Hi all, I want to modify the method that set use for see if there is already an object inside its obj-list. Something like this: ... It's possible? As far as I understand you, you need descriptors: http://users.rcn.com/python/download/Descriptor.htm -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
Ciao, Michele: On Thu, Sep 4, 2008 at 11:48 AM, Michele Petrazzo [EMAIL PROTECTED] wrote: Hi all, I want to modify the method that set use for see if there is already an object inside its obj-list. Something like this: class foo: pass bar1 = foo() bar1.attr = 1 bar2 = foo() bar2.attr = 1 set( (bar1, bar2), key=lambda o: o.attr) and, of course, set has only one value. It's possible? Thanks, Michele -- http://mail.python.org/mailman/listinfo/python-list looking at the source, maybe you could create a subclass of Set redefining the __contains__ method? Regards Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
On Thu, Sep 4, 2008 at 11:58 AM, Wojtek Walczak [EMAIL PROTECTED] wrote: On Thu, 04 Sep 2008 11:48:18 +0200, Michele Petrazzo wrote: Hi all, I want to modify the method that set use for see if there is already an object inside its obj-list. Something like this: ... It's possible? As far as I understand you, you need descriptors: http://users.rcn.com/python/download/Descriptor.htm I know descriptors a litte, Wojtek, but didn't use them often; can you elaborate a little more on your idea? -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list Saluti Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Issue warning if no return in function?
What would you suggest to check python programs for non-syntax error. One example I could think of that one might forget to return a value from a function. How could I check for these and maybe other mistakes? -- http://mail.python.org/mailman/listinfo/python-list
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Re: Issue warning if no return in function?
On Sep 4, 5:05 am, Poster28 [EMAIL PROTECTED] wrote: What would you suggest to check python programs for non-syntax error. One example I could think of that one might forget to return a value from a function. How could I check for these and maybe other mistakes? Check out PyLint (http://www.logilab.org/857) or PyChecker (http:// pychecker.sourceforge.net/). -- http://mail.python.org/mailman/listinfo/python-list
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Re: PyGUI as a standard GUI API for Python?
On 2008-09-04 11:14, Kay Schluehr wrote: On 4 Sep., 10:31, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 07:49, Kay Schluehr wrote: 3) Following the public rumor mill and the latest hype RIA i.e. the merge of web- and desktop applications with systems like Adobe AIR, JavaFX, Google Gears and MS Silverlight is the future of frontend development. With the exception of IronPython and Silverlight, Python hasn't even entered this game and no one knows if it ever will. Actually, it has already and quite some time ago: http://www.artima.com/weblogs/viewpost.jsp?thread=208528 The recipe is simple: use Python for the business logic, database interfacing, etc and have it talk to a Flex front-end via XML-RPC or REST. Python is still server-side in this scenario and plays no role in UI definitions. That depends on how you design the application. It is well possible to have Python drive the GUI by sending the required details to the Flex front-end via XML (ie. data-driven GUIs). So one doesn't get more than e.g. Django apps that respond to HTTP requests triggered by JavaScript forms except that JavaScript+HTML+Browser is replaced by Flex = AS3+MXML+FlashPlayer. You really can't compare the Flex stack to an AJAX stack. Flex has a lot more to offer for GUI programming than AJAX, it also doesn't suffer from the problems of AJAX having to support several different sets of browser or library bugs. We switched from an AJAX approach to a Flex-based approach last year and never even considered moving back again. The role of Python is somewhat arbitrary. This could change only if Python becomes a client side language executed by AVM, V8 etc. like IronPython in Silverlight. About separating UI from application logics by assigning functionality to different general purpose languages I have to admit that I don't think it is such a great idea ... In my experience, Flex + Python gives you the best of both worlds, the nice GUI features of Flex and the efficiency of Python for the business logic. A long time ago, there was a Python plugin for Netscape which allowed you to run Python straight in the browser. Perhaps it's time to revive such an idea... but then you're still missing out on the GUI part, since you're still stuck with what the browser has to offer in terms of widget support. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Sep 04 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 -- http://mail.python.org/mailman/listinfo/python-list
Re: Issue warning if no return in function?
On Thu, 04 Sep 2008 12:05:45 +0200, Poster28 wrote: What would you suggest to check python programs for non-syntax error. One example I could think of that one might forget to return a value from a function. How could I check for these and maybe other mistakes? Check pychecker or figleaf: http://pychecker.sourceforge.net http://darcs.idyll.org/~t/projects/figleaf/doc/ -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Serial I/O problem with pywin32 ?
On 3 Sep, 16:33, Diez B. Roggisch [EMAIL PROTECTED] wrote: Xavier schrieb: Hi, I try to access to a Bluetooth GPS data-logger with Python. I use pySerial. Sending and receiving little messages (~100 char) works fine. However, when I ask the GPS to dump the trails, it returns some Mbytes and here is the problem : in the stream of bytes, I randomly losts chunks of ~100bytes. I tried USPP and pyBlueZ instead of pySerial : same problem. It doesn't like it is a bufferoverun bug from me because : - the GPS seems to wait when I do not read the stream, - there is never more than 200 inWainting() characters, - my code to test it is quite simple : seriallink = serial.Serial(COM40) fileName = data.dump out = open(fileName, 'w') while 1: c = seriallink.read() out.write( %0.2X % ord(c)) print *, out.close() (with pyBluez : sock=BluetoothSocket( RFCOMM ) sock.connect((00:0A:..., 1))) I tried my program on two different PC with two Bluetooth dongle, (with pySerial, USPP, pyBluez). The same things are : - windows - the GPS (which works fine with the dumper program of the constructor) - pyWin32 I've found another guy with a similar problem : http://www.generation-nt.com/reponses/rs232-entraide-142097.html He says: - no problem with little messages - lost of one byte every hour when receiving a lot of data Any known problems with pywin32 and serial I/O when downloading a big stream of data ? From my experience with serial lines I'd say: that's the culprit. They tend to be rather unreliable, as there is no real protocol ensuring data integrity. You might consider downloading chunks of data if that's somehow possible, and re-try failed chunks. Diez Could be hardware flow control. See this sometimes on the bluetooth connections that are using Serial Port Protocol and the hardware flow control hasn't been physically implemented. Do you lose data after exactly the same amount of data has been received? -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from .NET and VB and C
On Thu, Sep 4, 2008 at 12:16 AM, Dennis Lee Bieber [EMAIL PROTECTED] wrote: On Wed, 3 Sep 2008 09:52:06 -0700 (PDT), ToPostMustJoinGroup22 [EMAIL PROTECTED] declaimed the following in comp.lang.python: have no preference with MySQL or SQL, stored procedures or ad-hoc queries. Please note: MySQL is specific relational database management system (RDBMs), which uses a dialect of structured query language (SQL). SQL by itself is just a semi-standardized query language -- and can technically be used to access non-relational DBMS (if any such are still in use), though the query processor would be a pain to program (map a relational join into a hierarchical DBMS schema? ugh). SO, I'm interested in using my Google App space (free 500MB) to develop a quick database application. Using Python. I found Dive Into Python which I will be reading shortly. So one question: what RDBMs are supported in that space? The appearance is not an RDBMS, at least, maybe it is, but under the surface. Looks more that you've persistent objects with a SQL-like language to query them. Regards Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
Mensanator [EMAIL PROTECTED] wrote: No, but blank cells are 0 as far as Excel is concerned. That behaviour causes nothing but trouble and I am saddened to see Python emulate such nonsense. Then you should feel glad that the Python sum() function *does* signal an error for the closest equivalent of blank cells in a list: sum([1, 2, 3, None, 5, 6]) Traceback (most recent call last): File stdin, line 1, in module TypeError: unsupported operand type(s) for +: 'int' and 'NoneType' Summing the elements of an empty list is *not* the same thing as summing elements of a list where one element is None. There are no empty boxes. There are only boxes with known quantities and those with unknown quantities. I hope that's not too ivory tower. The sum() function in Python requires exactly one box. That box can be empty, can contain known quantities (numbers, presumably), or unknown quantities (non-numbers, e.g., None). But you can't give it zero boxes, or three boxes. I don't have a strong view of whether sum([]) should return 0 or raise an error, but please do not mix that question up with what a sum over empty cells or over NULL values should yield. They are very different questions. As it happens, the SQL sum() function (at least in MySQL; I don't have any other database easily available, nor any SQL standard to read) does return NULL for a sum over the empty sequence, so you could argue that that would be the correct behaviour for the Python sum() function as well, but you can't argue that because a sum *involving* a NULL value returns NULL. -- Thomas Bellman, Lysator Computer Club, Linköping University, Sweden This isn't right. This isn't even wrong. ! bellman @ lysator.liu.se -- Wolfgang Pauli ! Make Love -- Nicht Wahr! -- http://mail.python.org/mailman/listinfo/python-list
cPickle
I have 3 objects and want to save in one pickle file. I used cPickle to dump 3 objects in a pkl file i.e cPickle.dump(object1, fileobject, -1) cPickle.dump(object2, fileobject, -1) cPickle.dump(object3, fileobject, -1) I have changed the 3rd object and want to save the updated 3rd object in the pickle file. I have to dump all the 3 objects again. Is there any way to dump only the 3rd object in to the pkl file. -- http://mail.python.org/mailman/listinfo/python-list
Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
Let's say I've a class a, where I can write: -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: PyGUI as a standard GUI API for Python?
On Thu, Sep 4, 2008 at 3:45 PM, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 11:14, Kay Schluehr wrote: On 4 Sep., 10:31, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 07:49, Kay Schluehr wrote: 3) Following the public rumor mill and the latest hype RIA i.e. the merge of web- and desktop applications with systems like Adobe AIR, JavaFX, Google Gears and MS Silverlight is the future of frontend development. With the exception of IronPython and Silverlight, Python hasn't even entered this game and no one knows if it ever will. Actually, it has already and quite some time ago: http://www.artima.com/weblogs/viewpost.jsp?thread=208528 The recipe is simple: use Python for the business logic, database interfacing, etc and have it talk to a Flex front-end via XML-RPC or REST. Python is still server-side in this scenario and plays no role in UI definitions. That depends on how you design the application. It is well possible to have Python drive the GUI by sending the required details to the Flex front-end via XML (ie. data-driven GUIs). So one doesn't get more than e.g. Django apps that respond to HTTP requests triggered by JavaScript forms except that JavaScript+HTML+Browser is replaced by Flex = AS3+MXML+FlashPlayer. You really can't compare the Flex stack to an AJAX stack. Flex has a lot more to offer for GUI programming than AJAX, it also doesn't suffer from the problems of AJAX having to support several different sets of browser or library bugs. We switched from an AJAX approach to a Flex-based approach last year and never even considered moving back again. The approach does seem quite impressive, but isn't Flex's platform neutrality quite over-rated ? I mean after-all, it assumes that Flex is available for and available on the platform. Flex today is not yet so ubiquitous as the JRE... Are there some established best-practices on how to package such applications -- s.a. shipping with its's own Flex runtime, offer-download if missing etc. ? What happens if owner of target machine decides to upgrade their version of Flex, will it impact the application package in anyway, and render rest of it non-upgradable ? The role of Python is somewhat arbitrary. This could change only if Python becomes a client side language executed by AVM, V8 etc. like IronPython in Silverlight. About separating UI from application logics by assigning functionality to different general purpose languages I have to admit that I don't think it is such a great idea ... In my experience, Flex + Python gives you the best of both worlds, the nice GUI features of Flex and the efficiency of Python for the business logic. A long time ago, there was a Python plugin for Netscape which allowed you to run Python straight in the browser. Perhaps it's time to revive such an idea... but then you're still missing out on the GUI part, since you're still stuck with what the browser has to offer in terms of widget support. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Sep 04 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 -- http://mail.python.org/mailman/listinfo/python-list -- regards, Banibrata http://www.linkedin.com/in/bdutta http://octapod.wordpress.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
Marco Bizzarri wrote: Let's say I've a class a, where I can write: Anticipating this obviously premature posting: http://dirtsimple.org/2004/12/python-is-not-java.html Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: cPickle
gopal mishra wrote: I have 3 objects and want to save in one pickle file. I used cPickle to dump 3 objects in a pkl file i.e cPickle.dump(object1, fileobject, -1) cPickle.dump(object2, fileobject, -1) cPickle.dump(object3, fileobject, -1) I have changed the 3^rd object and want to save the updated 3^rd object in the pickle file. I have to dump all the 3 objects again. Is there any way to dump only the 3^rd object in to the pkl file. No, there isn't. You could, of course, save each object in its own pickle file. Or use an object database like ZODB instead. -- Gerhard -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
On Thu, Sep 4, 2008 at 1:00 PM, Diez B. Roggisch [EMAIL PROTECTED] wrote: Marco Bizzarri wrote: Let's say I've a class a, where I can write: Anticipating this obviously premature posting: http://dirtsimple.org/2004/12/python-is-not-java.html Diez -- http://mail.python.org/mailman/listinfo/python-list Ehi, Diez, that was fast :-) ! Thanks for the link, I saw it in the past days and I read it; and I appreciated it a lot (actually, it was a door to a new world in Python, for me). But I'm asking something I feel is a little different, as you can read in my message, once it is full. Regards Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
Sorry... pressed enter but really didn't want to. As I said, let's say I have a class class A: def __init__(self): self.x = None Python makes the decision to allow the developers to directly access the attribute x, so that they can directly write: a.x = 1, or whatever; this has for me the unfortunate side effect that if I write, for example a.y = 1, when I really wanted to write a.x = 1 no one cares about it, and I'm unable to spot this error until later. Of course, I know that while I'm fresh, I've a good knowledge of the code, and anything else, I will be able to avoid such stupid errors; however, I'm afraid of the times when I'm tired, when I have to put my hands on the code of someone else, and so on. Please, understand that I'm not stating that python is wrong... after all, if it is wrong, I can move to a language like Java, which has a different approach on it. I'm really very interested in reading past discussion on it, if they are available. Regards Marco On Thu, Sep 4, 2008 at 12:57 PM, Marco Bizzarri [EMAIL PROTECTED] wrote: Let's say I've a class a, where I can write: -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
Michele Petrazzo wrote: Hi all, I want to modify the method that set use for see if there is already an object inside its obj-list. Something like this: class foo: pass bar1 = foo() bar1.attr = 1 bar2 = foo() bar2.attr = 1 set( (bar1, bar2), key=lambda o: o.attr) and, of course, set has only one value. It's possible? Using a decorator/delegate-pattern, yes: class Foo(object): def __init__(self, delegate): self.delegate = delegate def __hash__(self): return hash(self.delegate.attr) def __cmp__(self, other): return cmp(self.delegate.attr, other.delegate.attr) set(Foo(a) for a in bar1, bar2) Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
Of course, I know that while I'm fresh, I've a good knowledge of the code, and anything else, I will be able to avoid such stupid errors; however, I'm afraid of the times when I'm tired, when I have to put my hands on the code of someone else, and so on. Please, understand that I'm not stating that python is wrong... after all, if it is wrong, I can move to a language like Java, which has a different approach on it. I'm really very interested in reading past discussion on it, if they are available. This has not much to do with the question of setters and getters. Because in your code you could write def setX(self, x): self.y = x def getX(self): return self.x So the error occurs in the same way. What you are essentially asking is: why is python dynamic instead of static? Because *that* is what is the difference. In a static language, you need to declare first what you want to be available, e.g. which variables and methods are available and such. Of course then the compiler (or whoever evaluates the static declarations) can puke on you if you attempt a stunt like the one you describe. Python (and other languages such as Ruby, Javascript) chose other. They give you the freedom to add instance variables (or even methods) at will, with the cost of the occasional error like the above. OTOH, Java makes me write s much more code that me becoming tired and doing some stupid mistake (and there are lots of them doable in static languages as well, otherwise no C/C++ or Java-program would crash) becomes much more likelyYMMV. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from .NET and VB and C
Marco Bizzarri a écrit : On Thu, Sep 4, 2008 at 12:16 AM, Dennis Lee Bieber [EMAIL PROTECTED] wrote: On Wed, 3 Sep 2008 09:52:06 -0700 (PDT), ToPostMustJoinGroup22 [EMAIL PROTECTED] declaimed the following in comp.lang.python: have no preference with MySQL or SQL, stored procedures or ad-hoc queries. Please note: MySQL is specific relational database management system (RDBMs), which uses a dialect of structured query language (SQL). SQL by itself is just a semi-standardized query language -- and can technically be used to access non-relational DBMS (if any such are still in use), though the query processor would be a pain to program (map a relational join into a hierarchical DBMS schema? ugh). SO, I'm interested in using my Google App space (free 500MB) to develop a quick database application. Using Python. I found Dive Into Python which I will be reading shortly. So one question: what RDBMs are supported in that space? The appearance is not an RDBMS, at least, maybe it is, but under the surface. Not AFAIK, cf: http://en.wikipedia.org/wiki/BigTable -- http://mail.python.org/mailman/listinfo/python-list
Safely move an element into a heap
Hi, I wanted to know if does exist a safe way to, given a heap, move an arbitrary element to the first position of the heap. Something like: heap = [0,3,6,8,10] heapq.move_to_first_position(heap, 4) heap = [10, 0,3,6,8] --- Giampaolo http://code.google.com/p/pyftpdlib/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from .NET and VB and C
On Thu, Sep 4, 2008 at 1:23 PM, Bruno Desthuilliers [EMAIL PROTECTED] wrote: The appearance is not an RDBMS, at least, maybe it is, but under the surface. Not AFAIK, cf: http://en.wikipedia.org/wiki/BigTable -- http://mail.python.org/mailman/listinfo/python-list Thanks for the pointer, Bruno... I wrote from my memory, but there is some bank of it which need quick replace ;) -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Safely move an element into a heap
I'm not sure what you expect as an answer, but if you mean the heap as in the data structure, you can not just arbitrarily move one key where you want as it will destroy the heap property. Giampaolo Rodola' wrote: Hi, I wanted to know if does exist a safe way to, given a heap, move an arbitrary element to the first position of the heap. Something like: heap = [0,3,6,8,10] heapq.move_to_first_position(heap, 4) heap = [10, 0,3,6,8] --- Giampaolo http://code.google.com/p/pyftpdlib/ -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: cPickle
Le Thursday 04 September 2008 13:08:59 Gerhard Häring, vous avez écrit :
gopal mishra wrote:
I have 3 objects and want to save in one pickle file.
I used cPickle to dump 3 objects in a pkl file
i.e cPickle.dump(object1, fileobject, -1)
cPickle.dump(object2, fileobject, -1)
cPickle.dump(object3, fileobject, -1)
I have changed the 3^rd object and want to save the updated 3^rd object
in the pickle file.
I have to dump all the 3 objects again.
Is there any way to dump only the 3^rd object in to the pkl file.
No, there isn't. You could, of course, save each object in its own
pickle file. Or use an object database like ZODB instead.
Shelve is another alternative, shipped with python and rather straightforward.
Shelve as ZODB use pickles of objects but, unlike ZODB, won't need you change
anything to your actual classes.
[8]: import shelve
[9]: s = shelve.open('db')
[10]: a, b, c = 5, 4., (foo, bar)
[11]: s['a'], s['b'], s['c'] = a, b, c
[12]: s.close()
[13]:
[EMAIL PROTECTED] 13:46:42:~$ file db
db: Berkeley DB (Hash, version 8, native byte-order)
[EMAIL PROTECTED] 13:46:44:~$ ipython
[1]: import shelve
[2]: s = shelve.open('db')
[3]: for name, value in s.items() : print name, value
...:
b 4.0
a 5
c ('foo', 'bar')
[5]: del s['b']
[6]: s['c'] += ('baz',)
[7]: s.sync()
[8]:
[EMAIL PROTECTED] 13:48:12:~$ ipython
[1]: import shelve
[2]: s = shelve.open('db')
[3]: for name, value in s.items() : print name, value
...:
a 5
c ('foo', 'bar', 'baz')
The sync method may not work on all platform, maybe you'll have to close and
re-open the db file to write to disk.
--
_
Maric Michaud
--
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Re: Safely move an element into a heap
On 4 Set, 13:49, Alexandru Palade [EMAIL PROTECTED] wrote: I'm not sure what you expect as an answer, but if you mean the heap as in the data structure, you can not just arbitrarily move one key where you want as it will destroy the heap property. Giampaolo Rodola' wrote: Hi, I wanted to know if does exist a safe way to, given a heap, move an arbitrary element to the first position of the heap. Something like: heap = [0,3,6,8,10] heapq.move_to_first_position(heap, 4) heap = [10, 0,3,6,8] --- Giampaolo http://code.google.com/p/pyftpdlib/ -- http://mail.python.org/mailman/listinfo/python-list- Nascondi testo citato - Mostra testo citato - Could I be able to do that if every element I want to move will have the value of 0 which is the smallest value I can have into my heap? What I'm trying to do is implementing a timeout: sometimes I want a given event which was scheduled to happen within X seconds to happen immediately. --- Giampaolo http://code.google.com/p/pyftpdlib/ -- http://mail.python.org/mailman/listinfo/python-list
help in execfile function
Hi i have 3 python files and i want to execute the files sequentially using the execfile command.Hence ,i have written the following program fileList = [a.py,b.py,c.py] for fileName in fileList : execfile(fileName) however,when i try running it,the program keeps calling execfile on a.py and thus an infinite loop is created.I am running this on Windows XP. Please suggest a sloution whereby i can use execfile to execute all files in fileList.Please tell me where in my program i may have gone wrong. moijes12 -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
In article [EMAIL PROTECTED], Bruno Desthuilliers [EMAIL PROTECTED] wrote: Mathieu Prevot a écrit : 2008/9/4 Chris Rebert [EMAIL PROTECTED]: (snip) You're looking for the setattr() built-in function. In this exact case: setattr(a, arg, new_value) This is probably covered in the Python tutorial, please read it. Regards, Chris Indeed. I'll use: a.__setattr__(height, new_value) Please don't. Use the generic setattr() function instead. This holds for any __magic__ method : they are *implementation* for operators and generic functions - which you can think of as operators with a function syntax -, and are not meant to be called directly. You wouldn't write something like 2.__add__(3), would you ? Along with the good advice the usual suspects have given, my intuition is that there's an even better implementation that doesn't setattr() at all. While it's impossible to know, of course, because we don't have the original poster's true requirements, I conjecture that, rather than to link this [user-supplied] word to a class variable, what will serve him best is to regard the user text as an index into a class dictionary. -- http://mail.python.org/mailman/listinfo/python-list
Re: help in execfile function
On Thu, 04 Sep 2008 05:03:57 -0700, moijes12 wrote:
Hi
i have 3 python files and i want to execute the files sequentially using
the execfile command.Hence ,i have written the following program
fileList = [a.py,b.py,c.py]
for fileName in fileList :
execfile(fileName)
however,when i try running it,the program keeps calling execfile on a.py
and thus an infinite loop is created.I am running this on Windows XP.
Change the line execfile(fileName) to print fileName and you may
discover that the problem isn't with execfile but with your code.
Then read about modules and import, and you may discover that there is a
better way than execfile.
(I wish that eval, exec and execfile were hidden in a module where noobs
couldn't trip over them and decide they are the answer to every problem.
Sigh.)
Please suggest a sloution whereby i can use execfile to execute all
files in fileList.Please tell me where in my program i may have gone
wrong.
Looking into my crystal ball, I'm guessing that file a.py contains a line
that says execfile('a.py').
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
Marco Bizzarri wrote: looking at the source, maybe you could create a subclass of Set redefining the __contains__ method? Made some tries, but __contains__ are never called class foo(set): ... def __contains__(self, value): ... print value ... a = foo((1,2)) Thanks, Michele -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
Marco Bizzarri a écrit : Sorry... pressed enter but really didn't want to. As I said, let's say I have a class class A: def __init__(self): self.x = None Python makes the decision to allow the developers to directly access the attribute x, So do Java, if you make your attribute public (which would be a big error given Java's lack of support for computed attribute, but this is another problem). so that they can directly write: a.x = 1, or whatever; this has for me the unfortunate side effect that if I write, for example a.y = 1, when I really wanted to write a.x = 1 no one cares about it, I assume *you* do !-) But this is barely related to having explicit setters or not - it comes from the fact that the default[1] Python's object behaviour is to support arbitrary attribute setting. [1] some objects don't, but this is mostly for optimization reasons. and I'm unable to spot this error until later. Not sure, but IIRC tools like pylint or pychecker might be able to warn you about this. But anyway : Of course, I know that while I'm fresh, I've a good knowledge of the code, and anything else, I will be able to avoid such stupid errors; however, I'm afraid of the times when I'm tired, when I have to put my hands on the code of someone else, and so on. The edit/test cycle in Python is usually fast enough so you should spot the problem *pretty* quickly. This is at least what I learned from 8+ years of python (and a couple other dynamic languages) programming... Not to say that problems like the one you mention (or similar problems with dynamic typing etc) never happens, nor that they're never painful to track down and fix - just that they happen way less often than one might fear, and are most of the time really quickly spotted and fixed. Please, understand that I'm not stating that python is wrong... after all, if it is wrong, I can move to a language like Java, which has a different approach on it. I don't think it's a matter of right or wrong - mostly a matter of tradeoffs and balance. But if you go for static typing and (allegedly) provable correctness, you may want to have a look at languages like OCaml. I'm really very interested in reading past discussion on it, if they are available. Well... Most of these discussions alas boil down to bondagediscipline proponants asserting - against all evidences - that dynamic languages are unsafe and unusable for anything else than simple throw-away scripts or toy projects, and dynamic proponants arguing - against all evidences - that static typing and everything related is just a waste of time (FWIW, you might find myself in the first camp until approx year 2k and the second for the five or six following years). And sometimes, someone a bit more sensible trying to take a more balanced approach to the problem, usually to no avail. -- http://mail.python.org/mailman/listinfo/python-list
[ANN] The Python Papers, Volume 3 Issue 2
Hi everyone After a long wait of nearly 5 month, we are back in business to bring the latest edition of The Python Papers - Volume 3 Issue 2 (http:// ojs.pythonpapers.org/index.php/tpp/issue/current). From this issue onwards, we will be having only 3 issues per year instead of 4. This is in compliance with our ISSN registration. What's new = 1. We have expanded our editorial team with 2 new Associate Editors, Sarah Mount (from UK) and Guy Kloss from (New Zealand). 2. TPP is now managed using Open Journal System and it can be assessed at http://ojs.pythonpapers.org/tpp 3. Backporting of previous issues of TPP from Volume 1 Issue 1 is complete 4. We had soft-launched TWO new periodicals - The Python Papers Monographs (for monograph-length submissions which may include dissertations, conference proceedings, case studies and advanced-level lectures) and The Python Papers Source Codes (modeled after ACM Collected Algorithms and provides a collection of software and source codes, usually associated with papers published in The Python Papers and The Python Papers Monograph). They shall be TPPM and TPPSC respectively. 5. Collectively, TPP, TPPM and TPPSC will be umbrella-ed as The Python Papers Anthology (TPPA) and managed under the same editorial committee. 6. Probably the most important development to TPP is that TPP is currently indexed by a number of services, including Google Scholar and OAIster, as a result of using Open Journal System. So, please enjoy our latest edition and we look towards all of your continued support and contributions. Thank you. Cheers Maurice Ling Co-Editor-in-Chief, The Python Papers Anthology -- http://mail.python.org/mailman/listinfo/python-list
Re: use str as variable name
2008/9/4 Fredrik Lundh [EMAIL PROTECTED]: Bruno Desthuilliers wrote: You wouldn't write something like 2.__add__(3), would you ? Don't give the it's only OO if I write obj.method(args) crowd more bad ideas, please ;-) (...as Bruno implies, setattr(), len() et al can be and should be viewed as generic functions. A specific Python implementation may use custom code to implement behaviour for a given object; behaviour that's more efficient than a full Python-level method call. For example, in CPython, len(L) is about twice as fast as L.__len__() for built-in sequences.) Got it. Thanks :) Mathieu -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
Le Thursday 04 September 2008 14:31:23 Michele Petrazzo, vous avez écrit : Marco Bizzarri wrote: looking at the source, maybe you could create a subclass of Set redefining the __contains__ method? Made some tries, but __contains__ are never called No, __contains__ is only called with in operator, not for internal hashing. Anyway this solution is bad, you'll need to compare the new element with all the set contain, which would result in a O(n) algorithm for adding elements to the set in place of the O(1) it use. The right way to go is one like Diez show you in a previous post. class foo(set): ... def __contains__(self, value): ... print value ... a = foo((1,2)) -- _ Maric Michaud -- http://mail.python.org/mailman/listinfo/python-list
Re: The Python Papers, Volume 3 Issue 2
On Sep 4, 8:58 am, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi everyone After a long wait of nearly 5 month, we are back in business to bring the latest edition of The Python Papers - Volume 3 Issue 2 (http:// ojs.pythonpapers.org/index.php/tpp/issue/current). From this issue onwards, we will be having only 3 issues per year instead of 4. This is in compliance with our ISSN registration. What's new = 1. We have expanded our editorial team with 2 new Associate Editors, Sarah Mount (from UK) and Guy Kloss from (New Zealand). 2. TPP is now managed using Open Journal System and it can be assessed athttp://ojs.pythonpapers.org/tpp 3. Backporting of previous issues of TPP from Volume 1 Issue 1 is complete 4. We had soft-launched TWO new periodicals - The Python Papers Monographs (for monograph-length submissions which may include dissertations, conference proceedings, case studies and advanced-level lectures) and The Python Papers Source Codes (modeled after ACM Collected Algorithms and provides a collection of software and source codes, usually associated with papers published in The Python Papers and The Python Papers Monograph). They shall be TPPM and TPPSC respectively. 5. Collectively, TPP, TPPM and TPPSC will be umbrella-ed as The Python Papers Anthology (TPPA) and managed under the same editorial committee. 6. Probably the most important development to TPP is that TPP is currently indexed by a number of services, including Google Scholar and OAIster, as a result of using Open Journal System. So, please enjoy our latest edition and we look towards all of your continued support and contributions. Thank you. Cheers Maurice Ling Co-Editor-in-Chief, The Python Papers Anthology Good to see that the newest edition of the journal is out. Also, I believe the correct URL should either be: http://ojs.pythonpapers.org/ or http://ojs.pythonpapers.org/index.php/tpp Thanks for providing this great resource. Samir -- http://mail.python.org/mailman/listinfo/python-list
Re: How to write verbose scripts
Steven D'Aprano [EMAIL PROTECTED] writes: On Tue, 02 Sep 2008 13:07:33 -0400, Joe Riopel wrote: On Tue, Sep 2, 2008 at 12:55 PM, Steven D'Aprano [EMAIL PROTECTED] wrote: Is there a better way of doing this than the way I am going about it? Would the logging module help, and just print the output to the stdout (or a file) instead? Thank you to everyone who answered. As I feared, it seems that there's no really simple way of dealing with arbitrary messages at arbitrary parts of my code. I would think the 'logging' module *is* the simple way to do this. At least, it's as simple as it could be without leading to massive re-visiting of the arbitrary parts of one's code when later desiring to change the way the messages are handled. -- \ “We must become the change we want to see.” —Mahatma Gandhi | `\ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Assalamu'alaikum wr. wb.
Assalamu'alaikum wr. wb., Faith Freedom Indonesia (http://www.indonesia.faithfreedom.org/forum/) The Amazing Racist: Moslem Mosque (http://13gb.com/videos/923/) Forum Murtadin Indonesia (http://mantanmuslim.blogspot.com/) Wassalam -- http://mail.python.org/mailman/listinfo/python-list
Xpath for HTML processing
Can anyone suggest something inthat can process an XPath like the following: /html/body/table[2]/tbody/tr/td[5]/table/tbody/tr[3]/td/table[3]/ tbody/tr[5]/td Cheers -- http://mail.python.org/mailman/listinfo/python-list
path slashes cleaning
Hi, for scripts that take arguments, I would like to remove the trailing slash if it's present. Is there something else than: a='/usr/local/lib/' if a[-1] == '/': a = list(a) a.pop() ''.join(a) Thanks, Mathieu -- http://mail.python.org/mailman/listinfo/python-list
Re: path slashes cleaning
On Sep 4, 8:25 am, Mathieu Prevot [EMAIL PROTECTED] wrote: Hi, for scripts that take arguments, I would like to remove the trailing slash if it's present. Is there something else than: a='/usr/local/lib/' if a[-1] == '/': a = list(a) a.pop() ''.join(a) Thanks, Mathieu How about this: if a[-1] == '/': a = a[:-1] Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: path slashes cleaning
2008/9/4 Mathieu Prevot [EMAIL PROTECTED]:
Hi,
for scripts that take arguments, I would like to remove the trailing
slash if it's present.
Is there something else than:
a='/usr/local/lib/'
if a[-1] == '/':
a = list(a)
a.pop()
''.join(a)
A dummy
a.rstrip('/')
Sorry for the noise
Mathieu
--
http://mail.python.org/mailman/listinfo/python-list
Re: path slashes cleaning
On Thu, Sep 4, 2008 at 3:25 PM, Mathieu Prevot [EMAIL PROTECTED] wrote:
Hi,
for scripts that take arguments, I would like to remove the trailing
slash if it's present.
Is there something else than:
a='/usr/local/lib/'
if a[-1] == '/':
a = list(a)
a.pop()
''.join(a)
Thanks,
Mathieu
a.rstrip('/') does the job.
bye,
Francesco
--
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Re: Access to Windows Add/Remove Programs?
On Sep 3, 9:41 pm, Sean DiZazzo [EMAIL PROTECTED] wrote: On Sep 3, 7:13 pm, Gabriel Genellina [EMAIL PROTECTED] wrote: En Wed, 03 Sep 2008 21:51:59 -0300, Sean DiZazzo [EMAIL PROTECTED] escribi : I'm trying to find a way to get a list of all the installed programs on a Windows box via Python. I thought of a few hacks that might partially work, and then thought about Add/Remove Programs Seems like the right way to go. I looked over the pywin32 docs a bit, but nothing slapped me in the face. Is there any reliable way to get at that info? You may enumerate the entries under this registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall -- Gabriel Genellina Thank both of you. Perfect! ~Sean I have used both of these methods, but it should be noted that not all programs register themselves in the registry. The usual suspects are spyware related. But there are still a few programs that you can just download and unzip that don't write anything to the registry. But this does work for probably 99% of programs on Windows. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: PyGUI as a standard GUI API for Python?
On 2008-09-04 12:57, Banibrata Dutta wrote: On Thu, Sep 4, 2008 at 3:45 PM, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 11:14, Kay Schluehr wrote: On 4 Sep., 10:31, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-09-04 07:49, Kay Schluehr wrote: 3) Following the public rumor mill and the latest hype RIA i.e. the merge of web- and desktop applications with systems like Adobe AIR, JavaFX, Google Gears and MS Silverlight is the future of frontend development. With the exception of IronPython and Silverlight, Python hasn't even entered this game and no one knows if it ever will. Actually, it has already and quite some time ago: http://www.artima.com/weblogs/viewpost.jsp?thread=208528 The recipe is simple: use Python for the business logic, database interfacing, etc and have it talk to a Flex front-end via XML-RPC or REST. Python is still server-side in this scenario and plays no role in UI definitions. That depends on how you design the application. It is well possible to have Python drive the GUI by sending the required details to the Flex front-end via XML (ie. data-driven GUIs). So one doesn't get more than e.g. Django apps that respond to HTTP requests triggered by JavaScript forms except that JavaScript+HTML+Browser is replaced by Flex = AS3+MXML+FlashPlayer. You really can't compare the Flex stack to an AJAX stack. Flex has a lot more to offer for GUI programming than AJAX, it also doesn't suffer from the problems of AJAX having to support several different sets of browser or library bugs. We switched from an AJAX approach to a Flex-based approach last year and never even considered moving back again. The approach does seem quite impressive, but isn't Flex's platform neutrality quite over-rated ? I mean after-all, it assumes that Flex is available for and available on the platform. Flex today is not yet so ubiquitous as the JRE... Since Flex is compiled to Flash and runs inside the Flash player, it is fairly easy to get Flex apps running. You do have to have the Flash9 player installed and the default minimum is 9.0.115.0 for Flex builder 3. Are there some established best-practices on how to package such applications -- s.a. shipping with its's own Flex runtime, offer-download if missing etc. ? What happens if owner of target machine decides to upgrade their version of Flex, will it impact the application package in anyway, and render rest of it non-upgradable ? So far we have not had any such problems, but that could change when Flash10 starts to ship, of course. We currently ship the application as a server application. The only requirement on the client side is having a browser with Flash9 installed. Pointing the browser at the server will then load the compiled Flex application (as .swf file). An alternative approach is bundling the client as AIR application which then runs as stand-alone app on the client side, but we haven't tried that yet. The role of Python is somewhat arbitrary. This could change only if Python becomes a client side language executed by AVM, V8 etc. like IronPython in Silverlight. About separating UI from application logics by assigning functionality to different general purpose languages I have to admit that I don't think it is such a great idea ... In my experience, Flex + Python gives you the best of both worlds, the nice GUI features of Flex and the efficiency of Python for the business logic. A long time ago, there was a Python plugin for Netscape which allowed you to run Python straight in the browser. Perhaps it's time to revive such an idea... but then you're still missing out on the GUI part, since you're still stuck with what the browser has to offer in terms of widget support. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Sep 04 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Sep 04 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/
Investments Are Faltering in Chrysler and GMAC
Mr. Feinberg’s giant investment fund, Cerberus Capital Management, is racing to salvage multibillion-dollar investments in Chrysler, the smallest of the Detroit automakers, and GMAC, the financing arm of General Motors. But for Cerberus, named after the mythological three-headed dog who guards the gates of hell, the news keeps getting worse. On Wednesday, Chrysler, which owns the Jeep and Dodge brands, said its sales in the United States fell by a third in August — nearly twice the industry average — as the downturn in the auto business dragged on. Honda eclipsed Chrysler as the nation’s No. 4 seller of cars, and Nissan is closing in fast. The same day, GMAC, in which Cerberus holds a 51 percent stake, said it was trying to stanch the bleeding from a business that was supposed to be immune to the ups and downs of the car industry: home mortgage lending. GMAC and its home loan unit, Residential Capital, announced that they would dismiss 5,000 employees, or 60 percent of the unit’s staff, and close all 200 of its retail mortgage branches. It is quite a comedown for Mr. Feinberg, who founded Cerberus in 1992 with $10 million and was initially hailed as a savior at Chrysler. Over the years, Cerberus excelled by gaining control of companies in bankruptcy and nursing them back to financial health. Now, Mr. Feinberg’s purchase of Chrysler and his deal for GMAC have knocked Cerberus down a peg. “Early on, in the Cerberus deal for Chrysler, when it first did these auto industry investments, the story was about how big and influential these funds are, that they think they can buy these iconic industrial companies,” said Colin C. Blaydon, director of the Center for Private Equity and Entrepreneurship at the Tuck School of Business at Dartmouth College. “So far, it does not seem to be working out well for them.” Chrysler is still recovering from its split a year ago from its German partner, Daimler, and is undergoing a big revamping under Cerberus. Top executives at Cerberus have said they are determined to fix the company and that their $7.4 billion investment will pay off. A Cerberus spokesman said in a statement on Wednesday that it remained confident in its management of Chrysler and GMAC. “No one is pleased with current market conditions,” he said. “However, Cerberus is a patient investor and not a market timer, and we take a long-term view of our investments. Our funds are structured accordingly.” Mr. Feinberg hired Robert L. Nardelli, the former chief executive of Home Depot, to turn Chrysler around. Their plan hinges on new offerings beginning in 2010. Since Cerberus acquired Chrysler, the automaker has been trying to squeeze out costs. It has announced the elimination of 28,000 jobs and sold $500 million worth of assets. Last week, Chrysler announced that it was studying a sale of its Dodge Viper sports car business. But like its larger competitors, General Motors and Ford Motor, Chrysler has faced questions over its ability to ride out a downturn in American auto sales that is expected to stretch through 2009. All three Detroit automakers have been hit hard by the sharp decline in sales of pickup trucks, sport utility vehicles and vans that followed the rise in gas prices this year. Chrysler, which has released limited financial data since Cerberus bought it, ended June with $11.7 billion in cash and had earnings before interest, tax, depreciation and amortization of $1.1 billion in the first half of the year. But with limited access to financial data, some analysts are skeptical of its overall health. The news on Wednesday from GMAC, meantime, underscored that Cerberus also must contend with the housing slump, which has led to huge losses at lenders across the spectrum. That includes Residential Capital, which became one of the nation’s biggest mortgage providers and plunged into the market for riskier home loans that could not be sold to Fannie Mae or Freddie Mac, the mortgage finance giants that have run into trouble themselves. Now, many of those loans are defaulting as home prices fall and the economy weakens. This summer, Residential Capital and its bondholders restructured $14 billion in bonds to ease its debt burden. That restructuring and new loans from GMAC have bought the company time to work out its problems, but analysts say it may not be enough to save the firm from rising defaults on mortgages. Residential Capital bonds are trading at about 70 cents on the dollar. “They have some time,” said Andrew Feltus, a bond fund manager at Pioneer Investments. But, he added, “This environment is going against them.” www.my-quickloans.com/finance -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
On Thu, Sep 4, 2008 at 3:07 PM, Maric Michaud [EMAIL PROTECTED] wrote: Le Thursday 04 September 2008 14:31:23 Michele Petrazzo, vous avez écrit : Marco Bizzarri wrote: looking at the source, maybe you could create a subclass of Set redefining the __contains__ method? Made some tries, but __contains__ are never called No, __contains__ is only called with in operator, not for internal hashing. Anyway this solution is bad, you'll need to compare the new element with all the set contain, which would result in a O(n) algorithm for adding elements to the set in place of the O(1) it use. Thanks for the clarification, Maric; I take notices to watch source more closely next time (( hopefully, before writing a wrong answer )). Regards Marco _ Maric Michaud -- http://mail.python.org/mailman/listinfo/python-list -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
On Thu, Sep 4, 2008 at 1:19 PM, Diez B. Roggisch [EMAIL PROTECTED] wrote: What you are essentially asking is: why is python dynamic instead of static? Most probably you're right. Maybe I will make a trip back to my university books and take a look at them again :-) Thanks Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
On Thu, Sep 4, 2008 at 4:39 PM, Marco Bizzarri [EMAIL PROTECTED] wrote: Most probably you're right. Maybe I will make a trip back to my university books and take a look at them again :-) Meant: you *are* right. Sorry. Saluti Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Numeric literal syntax
Alexander Schmolck wrote: A problem is that '1234' in Python is a string, so using ' in numbers looks a bit dangerous to me (and my editor will color those numbers as alternated strings, I think). Yeah, editors, especially those with crummy syntax highlighting (like emacs) might get it wrong. This should be easy enough to fix though. instead of forcing all editor developers to change their Python modes to allow you to use a crude emulation of a typographic convention in your Python source code, why not ask a few of them to implement the correct typographic convention (thin spaces) in their Python mode? /F -- http://mail.python.org/mailman/listinfo/python-list
Read Binary data
Hi guys,
I am trying to read a binary file created by the following matlab
command:
fid=fopen('a.bin','w','b'); fwrite(fid,a,'real*8'); fclose(fid);, and
wondering how to do it in Python. I googled it but still get
confused.
'b' in fopen is for 'big-endian', 'real*8' in fwrite is for 64bit
float.
Thank you very much!
Jinbo Wang
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Function decorators
Good day all, I am learning Python and came up to decorators. The question is: Why does function FoodList return value None? The code in attachment. Thank you, Aigars testingVarLogger.py Description: application/unknown-application-x-python -- http://mail.python.org/mailman/listinfo/python-list
Re: Function decorators
Aigars Aigars wrote: Good day all, I am learning Python and came up to decorators. The question is: Why does function FoodList return value None? The code in attachment. Thank you, Aigars -- http://mail.python.org/mailman/listinfo/python-list First of all, you should always inherit from object whenever it is possible. Then the answer: you did not return the result. Instead of self.func(*args, **kwargs) use this: return self.func(*args, **kwargs) Corrected example attached. Best, Laszlo class Logger(object): def __init__(self, function): self.func = function def __call__(self, *args, **kwargs): print Function %s called with args = %s, kwargs = %s % (self.func.__name__, str(args), str(kwargs)) return self.func(*args, **kwargs) # Return is important here! @Logger def FoodList(a, b, c=spam): text = Food is %s, %s, %s % (a, b, c) print text return text if __name__ == __main__: a = FoodList(eggs, potatoes) print a -- http://mail.python.org/mailman/listinfo/python-list
Re: overwrite set behavior
On Thu, 4 Sep 2008 12:06:14 +0200, Marco Bizzarri wrote: As far as I understand you, you need descriptors: http://users.rcn.com/python/download/Descriptor.htm I know descriptors a litte, Wojtek, but didn't use them often; can you elaborate a little more on your idea? Marco, I think that I misunderstood the OP, but I was thinking about immutable (or set-once) attributes. Something like this: --- class SetOnce(object): def __init__(self): self._attr1 = self._attr1flag = False def setatt(self, x): if self._attr1flag: raise ValueError(attribute already set) self._attr1flag = True self._attr1 = x def getatt(self): return self._attr1 attr1 = property(getatt, setatt) a = SetOnce() a.attr1 = 1 print a.attr1 try: a.attr1 = 2 except ValueError: print a.attr1 --- $ python immutattr.py 1 1 $ -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Function decorators
In article [EMAIL PROTECTED], Aigars Aigars [EMAIL PROTECTED] wrote: Good day all, I am learning Python and came up to decorators. The question is: Why does function FoodList return value None? Because the function doesn't return anything, and in Python a function that doesn't explicitly return anything returns None. The code in attachment. Thanks for not just pasting it into the post, like so: class Logger: def __init__(self, function): self.func = function def __call__(self, *args, **kwargs): print Function %s called with args = %s, kwargs = %s % (self.func.__name__, str(args), str(kwargs)) self.func(*args, **kwargs) @Logger def FoodList(a, b, c=spam): text = Food is %s, %s, %s % (a, b, c) print text return text if __name__ == __main__: a = FoodList(eggs, potatoes) print a Thank you, Aigars- [Image] -- David C. Ullrich -- http://mail.python.org/mailman/listinfo/python-list
Re: Function decorators
Aigars Aigars schrieb: Good day all, I am learning Python and came up to decorators. The question is: Why does function FoodList return value None? The code in attachment. Because the __call__ in Logger doesn't return the value of self.func. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: path slashes cleaning
On Sep 4, 6:32 am, Francesco Guerrieri [EMAIL PROTECTED]
wrote:
On Thu, Sep 4, 2008 at 3:25 PM, Mathieu Prevot [EMAIL PROTECTED] wrote:
Hi,
for scripts that take arguments, I would like to remove the trailing
slash if it's present.
Is there something else than:
a='/usr/local/lib/'
if a[-1] == '/':
a = list(a)
a.pop()
''.join(a)
Thanks,
Mathieu
a.rstrip('/') does the job.
bye,
Francesco
[1]: import os.path
[2]: os.path.normpath('/usr/bin')
'/usr/bin'
[3]: os.path.normpath('/usr/bin/')
'/usr/bin'
And on windows:
[1]: import os.path
[2]: os.path.normpath(r'c:\data')
'c:\\data'
[3]: os.path.normpath('c:\\data\\')
'c:\\data'
Use the functions provided in os.path.
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Re: Read Binary data
Mars creature wrote:
I am trying to read a binary file created by the following matlab
command:
fid=fopen('a.bin','w','b'); fwrite(fid,a,'real*8'); fclose(fid);, and
wondering how to do it in Python. I googled it but still get
confused.
'b' in fopen is for 'big-endian', 'real*8' in fwrite is for 64bit
float.
f = open(a.bin, rb) # read binary data
s = f.read() # read all bytes into a string
import array, sys
a = array.array(f, s) # f for float
if sys.byteorder != big:
a.byteswap()
/F
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Re: max(), sum(), next()
In article
[EMAIL PROTECTED],
Mensanator [EMAIL PROTECTED] wrote:
On Sep 3, 2:18 pm, Laszlo Nagy [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
Empty Python lists [] don't know the type of the items it will
contain, so this sounds strange:
sum([])
0
Because that [] may be an empty sequence of someobject:
You are right in that sum could be used to sum arbitrary objects.
However, in 99.99% of the cases, you will be summing numerical values.
When adding real numbers, the neutral element is zero. ( X + 0 = X) It
is very logical to return zero for empty sequences.
No it isn't. Nothing is not 0, check with MS-Access, for instance:
Null + 1 returns Null. Any arithmetic expression involving a
Null evaluates to Null. Adding something to an unknown returns
an unknown, as it should.
It is a logical fallacy to equate unknown with 0.
Which has nothing to do with the right value for an
empty sum. If they hear about what you said here in
sci.math they're gonna kick you out - what do you
imagine the universally accepted value of \sum_{j=1}^0
is?
For example, the water table elevation in ft above Mean Sea Level
is WTE = TopOfCasing - DepthToWater.
TopOfCasing is usually known and constant (until resurveyed).
But DepthToWater may or may not exist for a given event (well
may be covered with fire ants, for example).
Now, if you equate Null with 0, then the WTE calculation says
the water table elevation is flush with the top of the well,
falsely implying that the site is underwater.
And, since this particular site is on the Mississippi River,
it sometimes IS underwater, but this is NEVER determined by
water table elevations, which, due to the CORRECT treatment
of Nulls by Access, never returns FALSE calculations.
sum([])
0
is a bug, just as it's a bug in Excel to evaluate blank cells
as 0. It should return None or throw an exception like sum([None,1])
does.
Same way, if we would have a prod() function, it should return one for
empty sequences because X*1 = X. The neutral element for this operation
is one.
Of course this is not good for summing other types of objects. But how
clumsy would it be to use
sum( L +[0] )
or
if L:
value = sum(L)
else:
value = 0
instead of sum(L).
Once again, this is what sum() is used for in most cases, so this
behavior is the expected one.
Another argument to convince you: the sum() function in SQL for empty
row sets returns zero in most relational databases.
But of course it could have been implemented in a different way... I
believe that there have been excessive discussions about this decision,
and the current implementation is very good, if not the best.
Best,
Laszlo
--
David C. Ullrich
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Re: max(), sum(), next()
In article [EMAIL PROTECTED], [EMAIL PROTECTED] wrote: Empty Python lists [] don't know the type of the items it will contain, so this sounds strange: sum([]) 0 Because that [] may be an empty sequence of someobject: sum(s for s in [a, b] if len(s) 2) 0 In a statically typed language in that situation you may answer the initializer value of the type of the items of the list, as I do in the sum() in D. This sounds like a more correct/clean thing to do: max([]) Traceback (most recent call last): File stdin, line 1, in module ValueError: max() arg is an empty sequence So it may be better to make the sum([]) too raise a ValueError, I don't see why you feel the two should act the same. At least in mathematics, the sum of the elements of the empty set _is_ 0, while the maximum element of the empty set is undefined. And both for good reason: (i) If A and B are disjoint sets we certainly want to have sum(A union B) = sum(A) + sum(B). This requires sum(empty set) = 0. (ii) If A is a subset of B then we should have max(A) = max(B). This requires that max(empty set) be something that's smaller than everything else. So we give up on that. in Python 3/3.1 (if this isn't already true). On the other hand often enough I have code like this: max(fun(x) for x in iterable if predicate(x)) This may raise the ValueError both if iterable is empty of if the predicate on its items is always false, so instead of catching exceptions, that I try to avoid, I usually end with a normal loop, that's readable and fast: max_value = smallvalue for x in iterable: if predicate(x): max_value = max(max_value, fun(x)) Where running speed matters, I may even replace that max(max_value, fun(x)) with a more normal if/else. A possible alternative is to add a default to max(), like the next() built-in of Python 2.6: max((fun(x) for x in iterable if predicate(x)), default=smallvalue) This returns smallvalue if there are no items to compute the max of. Bye, bearophile -- David C. Ullrich -- http://mail.python.org/mailman/listinfo/python-list
Re: Read Binary data
On Sep 4, 12:03 pm, Fredrik Lundh [EMAIL PROTECTED] wrote:
Mars creature wrote:
I am trying to read a binary file created by the following matlab
command:
fid=fopen('a.bin','w','b'); fwrite(fid,a,'real*8'); fclose(fid);, and
wondering how to do it in Python. I googled it but still get
confused.
'b' in fopen is for 'big-endian', 'real*8' in fwrite is for 64bit
float.
f = open(a.bin, rb) # read binary data
s = f.read() # read all bytes into a string
import array, sys
a = array.array(f, s) # f for float
if sys.byteorder != big:
a.byteswap()
/F
Thanks Fredrik! I appreciate it!
The only thing is that a = array.array(f, s) should be a =
array.array(d, s) as the data is double precision.
Thanks again!
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Re: Late initialization using __getattribute__
so unfortunately I think I need to use __getattribute__
to do this. I'm doing all this just to make the connection not
actually connect until used.
I may be dumb, but I don't get how this is supposed to solve your
problem. But anyway : there's a known design pattern for what you're
trying to do, that doesn't require mixins nor messing with
__getattribute__ (which, I repeat, is more often than not something you
*don't* want to do). The name of the design pattern is proxy. I
strongly suggest that you 1/ try to cure the real problem instead of
hacking around and 2/ read about the proxy design pattern.
My 2 cents...
I like the idea of mix-ins, but can't figure out how to make a proxy
work that way.
You mean, how to use a proxy for lazy initialization ? Heck, that's
the exact use case in the GoF.
I mean, how to make a MixIn class that uses the proxy pattern. I'd
like to be able to do something like this:
class SuperCursor(FeatureOneMixIn, FeatureTwoMixin, ...,
VanillaCursor): pass
This works with my current implementation. After thinking about it
more, I think I've got such a thing written. I had to use
inspect.getmro and new.classobj to do it, but it works and it honors
the usual mro (as far as I can tell). I've put the code at the bottom
to (try to) maintain readability.
For a long time I had a proxy class that added five or
six features on top of the MySQLdb package, but it wasn't configurable
enough, and I'm working on splitting each feature into its own MixIn
class.
As an aside, this is working for me pretty well. The reconnect
method (inheritied from a Reconnectable mixin) uses several of the
object's attributes, so I need to set _inited beforehand so that I
don't get into an infinite __getattribute__ loop. What I'd *really*
like to do is remove __getattribute__ from the object at that point.
You can't. Or, more exactly, all you can do is remove __getattribute__
from the mixin class - but then the mixin class won't work anymore. I
don't mean to be condescendant, but it looks like you don't have a clear
understanding of Python's object model here - else you wouldn't even
consider doing such a thing. FWIW, I posted a solution based on the
__getattr__ hook, which did work - at least for the specs implied by
your code snippet.
My toy example turned out to be not the best representation of the
problem.
The base class has attributes that exist but either throw errors or
segfault
if used before reconnect() is called. This means that I need to
capture more than
just the attributes that would throw AttributeError.
#CODE
class Base(object):
def __init__(self, *args, **kwargs):
self.args = args
self.kwargs = kwargs
def __str__(self): return Base object created with %s %s %
(self.args, self.kwargs)
class MixIn2(object):
def __str__(self):
return MixIn2 with %s % super(MixIn2, self).__str__()
class MixIn1(object):
def __str__(self):
return MixIn1 with %s % super(MixIn1, self).__str__()
class ProxyMixIn(object):
def __init__(self, *args, **kwargs):
self.__proxied = None
self.__args = args
self.__kwargs = kwargs
def __getattr__(self, attr):
print Getting, attr
try: return getattr(self.__proxied, attr)
except AttributeError:
if self.__proxied: raise
else:
from inspect import getmro
mro = getmro(self.__class__)
mro = mro[list(mro).index(ProxyMixIn) + 1:]
print Proxied mro, mro
from new import classobj
self.__proxied = classobj(Proxied, mro, globals())
(*self.__args, **self.__kwargs)
return getattr(self.__proxied, attr)
def __str__(self):
return Proxy of %s % super(ProxyMixIn, self).__str__()
class Proxy(MixIn1, ProxyMixIn, MixIn2, Base): pass
def main():
p = Proxy(1,2,3, one=1, two=2)
print p
main()
#OUTPUT##
Getting args
Proxied mro (class '__main__.MixIn2', class '__main__.Base', type
'object')
Getting kwargs
MixIn1 with Proxy of MixIn2 with Base object created with (1, 2,
3) {'two': 2, 'one': 1}
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Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
On Sep 4, 7:09 am, Marco Bizzarri [EMAIL PROTECTED] wrote: Sorry... pressed enter but really didn't want to. As I said, let's say I have a class class A: def __init__(self): self.x = None Python makes the decision to allow the developers to directly access the attribute x, so that they can directly write: a.x = 1, or whatever; this has for me the unfortunate side effect that if I write, for example a.y = 1, when I really wanted to write a.x = 1 no one cares about it, and I'm unable to spot this error until later. Of course, I know that while I'm fresh, I've a good knowledge of the code, and anything else, I will be able to avoid such stupid errors; however, I'm afraid of the times when I'm tired, when I have to put my hands on the code of someone else, and so on. So what happens in Java (or any language for that matter) if there are indeed two attributes x and y with the same type and you mistype the one for the other ? Or if you meant to write x-y instead of y-x ? When coding tired or on someone's else code, stupid errors are the ones you should worry the least about. George -- http://mail.python.org/mailman/listinfo/python-list
Right to left language support
Most of you probably speaks Latin language, so you wont understand the problem. when I try to write Hebrew in my statictext the last punctuation marks get mixed up. does someone have a solution for this? this is the code : text=wx.StaticText(panel3, -1, Hebrew_string, style=wx.ALIGN_RIGHT) thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: Read Binary data
Am Thu, 04 Sep 2008 18:03:54 +0200 schrieb Fredrik Lundh: I am trying to read a binary file [...] f = open(a.bin, rb) # read binary data s = f.read() # read all bytes into a string import array, sys a = array.array(f, s) # f for float if sys.byteorder != big: a.byteswap() For more complicated structures, the struct module may help. HTH. Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Help needed to freeze a script.
Did you try py2exe instead offreeze? On the page http://www.py2exe.org/index.cgi/WorkingWithVariousPackagesAndModules there is only one brief mention of numpy packaging troubles, suggesting that it might work better. I have used py2exe in the past without much trouble. Unfortunately, I'm working under Linux and py2exe works only for windows as far as I know. Do you know if py2exe executable embedding a lot of C extensions - like numpy and scipy - can ben executed on another computer, with a different architecture (64bits vs 32 bits) and a different OS ? -- LB -- http://mail.python.org/mailman/listinfo/python-list
Re: Understanding the pythonic way: why a.x = 1 is better than a.setX(1) ?
On Thu, Sep 4, 2008 at 4:09 AM, Marco Bizzarri [EMAIL PROTECTED] wrote: Sorry... pressed enter but really didn't want to. As I said, let's say I have a class class A: def __init__(self): self.x = None Python makes the decision to allow the developers to directly access the attribute x, so that they can directly write: a.x = 1, or whatever; this has for me the unfortunate side effect that if I write, for example a.y = 1, when I really wanted to write a.x = 1 no one cares about it, and I'm unable to spot this error until later. Of course, I know that while I'm fresh, I've a good knowledge of the code, and anything else, I will be able to avoid such stupid errors; however, I'm afraid of the times when I'm tired, when I have to put my hands on the code of someone else, and so on. Please, understand that I'm not stating that python is wrong... after all, if it is wrong, I can move to a language like Java, which has a different approach on it. I'm really very interested in reading past discussion on it, if they are available. Regards Marco I think the most obvious solution to the problem is effective unit tests. If you type a.y =1 and have a test that asserts a.x == 1 then you would quite quickly discover that you made a typo. -- Stand Fast, tjg. [Timothy Grant] -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 4, 11:13 am, David C. Ullrich [EMAIL PROTECTED] wrote:
In article
[EMAIL PROTECTED],
Mensanator [EMAIL PROTECTED] wrote:
On Sep 3, 2:18 pm, Laszlo Nagy [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
Empty Python lists [] don't know the type of the items it will
contain, so this sounds strange:
sum([])
0
Because that [] may be an empty sequence of someobject:
You are right in that sum could be used to sum arbitrary objects.
However, in 99.99% of the cases, you will be summing numerical values.
When adding real numbers, the neutral element is zero. ( X + 0 = X) It
is very logical to return zero for empty sequences.
No it isn't. Nothing is not 0, check with MS-Access, for instance:
Null + 1 returns Null. Any arithmetic expression involving a
Null evaluates to Null. Adding something to an unknown returns
an unknown, as it should.
It is a logical fallacy to equate unknown with 0.
Which has nothing to do with the right value for an
empty sum.
I'm less concerned about the right value than a consistent
value. I'm fairly certain you can't get 0 from a query that
returns no records, so I don't like seeing empty being
treated as 0, even if it means that in set theory because
databases aren't sets.
If they hear about what you said here in
sci.math they're gonna kick you out
They usually don't kick me out, just kick me.
- what do you
imagine the universally accepted value of \sum_{j=1}^0
is?
I can't follow your banter, so I'm not sure what it should be.
For example, the water table elevation in ft above Mean Sea Level
is WTE = TopOfCasing - DepthToWater.
TopOfCasing is usually known and constant (until resurveyed).
But DepthToWater may or may not exist for a given event (well
may be covered with fire ants, for example).
Now, if you equate Null with 0, then the WTE calculation says
the water table elevation is flush with the top of the well,
falsely implying that the site is underwater.
And, since this particular site is on the Mississippi River,
it sometimes IS underwater, but this is NEVER determined by
water table elevations, which, due to the CORRECT treatment
of Nulls by Access, never returns FALSE calculations.
sum([])
0
is a bug, just as it's a bug in Excel to evaluate blank cells
as 0. It should return None or throw an exception like sum([None,1])
does.
Same way, if we would have a prod() function, it should return one for
empty sequences because X*1 = X. The neutral element for this operation
is one.
Of course this is not good for summing other types of objects. But how
clumsy would it be to use
sum( L +[0] )
or
if L:
value = sum(L)
else:
value = 0
instead of sum(L).
Once again, this is what sum() is used for in most cases, so this
behavior is the expected one.
Another argument to convince you: the sum() function in SQL for empty
row sets returns zero in most relational databases.
But of course it could have been implemented in a different way... I
believe that there have been excessive discussions about this decision,
and the current implementation is very good, if not the best.
Best,
Laszlo
--
David C. Ullrich
--
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Re: Python and Cyrillic characters in regular expression
On Sep 4, 3:42 pm, phasma [EMAIL PROTECTED] wrote:
Hi, I'm trying extract all alphabetic characters from string.
reg = re.compile('(?u)([\w\s]+)', re.UNICODE)
You don't need both (?u) and re.UNICODE: they mean the same thing.
This will actually match letters and whitespace.
buf = re.match(string)
But it's doesn't work. If string starts from Cyrillic character, all
works fine. But if string starts from Latin character, match returns
only Latin characters.
I'm encoding the Unicode results as UTF-8 in order to print them, but
I'm not having a problem with it otherwise:
Program
===
# -*- coding: utf-8 -*-
import re
reg = re.compile('(?u)([\w\s]+)')
found = reg.match(uya я)
print found.group(1).encode(utf-8)
found = reg.match(uя ya)
print found.group(1).encode(utf-8)
Output
==
ya я
я ya
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Re: Python and Cyrillic characters in regular expression
phasma wrote:
Hi, I'm trying extract all alphabetic characters from string.
reg = re.compile('(?u)([\w\s]+)', re.UNICODE)
buf = re.match(string)
But it's doesn't work. If string starts from Cyrillic character, all
works fine. But if string starts from Latin character, match returns
only Latin characters.
can you provide a few sample strings that show this behaviour?
/F
--
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Re: max(), sum(), next()
On Sep 4, 2:05 am, Thomas Bellman [EMAIL PROTECTED] wrote: Mensanator [EMAIL PROTECTED] wrote: No, but blank cells are 0 as far as Excel is concerned. That behaviour causes nothing but trouble and I am saddened to see Python emulate such nonsense. Then you should feel glad that the Python sum() function *does* signal an error for the closest equivalent of blank cells in a list: sum([1, 2, 3, None, 5, 6]) Traceback (most recent call last): File stdin, line 1, in module TypeError: unsupported operand type(s) for +: 'int' and 'NoneType' Yes, I am in fact happy to see that behaviour. Summing the elements of an empty list is *not* the same thing as summing elements of a list where one element is None. So, sum([1, 2, 3, None, 5, 6]) Traceback (most recent call last): File pyshell#0, line 1, in module sum([1, 2, 3, None, 5, 6]) TypeError: unsupported operand type(s) for +: 'int' and 'NoneType' gives me an error. As does sum([None, None, None, None, None, None]) Traceback (most recent call last): File pyshell#1, line 1, in module sum([None, None, None, None, None, None]) TypeError: unsupported operand type(s) for +: 'int' and 'NoneType' Why then, doesn't sum([A for A in [None, None, None, None, None, None] if A != None]) 0 give me an error? Ok, it's not a bug. This behaviour is by design. - Microsoft Knowledge Base I don't like it, but I guess I'll just have to live with it. There are no empty boxes. There are only boxes with known quantities and those with unknown quantities. I hope that's not too ivory tower. The sum() function in Python requires exactly one box. That box can be empty, can contain known quantities (numbers, presumably), or unknown quantities (non-numbers, e.g., None). But you can't give it zero boxes, or three boxes. I don't have a strong view of whether sum([]) should return 0 or raise an error, but please do not mix that question up with what a sum over empty cells or over NULL values should yield. They are very different questions. Ok, but I don't understand why an empty list is a valid sum whereas a list containing None is not. As it happens, the SQL sum() function (at least in MySQL; I don't have any other database easily available, nor any SQL standard to read) does return NULL for a sum over the empty sequence, so you could argue that that would be the correct behaviour for the Python sum() function as well, but you can't argue that because a sum *involving* a NULL value returns NULL. I'm not following that. Are you saying a query that returns no records doesn't have a specific field containg a Null so there are no Nulls to poison the sum? ...tap...tap...tap. Ok, I can see that, but you don't get 0 either. -- Thomas Bellman, Lysator Computer Club, Linköping University, Sweden This isn't right. This isn't even wrong. ! bellman @ lysator.liu.se -- Wolfgang Pauli ! Make Love -- Nicht Wahr! -- http://mail.python.org/mailman/listinfo/python-list
Re: Xpath for HTML processing
Astley Le Jasper wrote: Can anyone suggest something inthat can process an XPath like the following: /html/body/table[2]/tbody/tr/td[5]/table/tbody/tr[3]/td/table[3]/ tbody/tr[5]/td [skipping the obvious joke answer to your question] In case you're asking for a tool that can process HTML using XPath, try lxml.html. http://codespeak.net/lxml Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Thu, 4 Sep 2008 10:57:35 -0700 (PDT), Mensanator wrote: Why then, doesn't sum([A for A in [None, None, None, None, None, None] if A != None]) 0 give me an error? Because [A for A in [None, None, None, None, None, None] if A != None] returns an empty list, and sum([]) doesn't return an error. What did you expect? -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
