ANN: ConfigObj 4.6.0 and Validate 1.0.0 released
Finally a fresh release ConfigObj and Validate. * ConfigObj Home page: http://www.voidspace.org.uk/python/configobj.html * Validate Home page: http://www.voidspace.org.uk/python/validate.html **ConfigObj** is a simple to use but powerful Python library for the reading and writing of configuration (ini) files. Through **Validate** it integrates a config file validation and type conversion system. Features of ConfigObj include: * Nested sections (subsections), to any level * List values * Multiple line values * Full Unicode support * String interpolation (substitution) * Integrated with a powerful validation system - including automatic type checking/conversion - and allowing default values - repeated sections * All comments in the file are preserved * The order of keys/sections is preserved * Powerful ``unrepr`` mode for storing/retrieving Python data-types Release 4.6.0 fixes bugs and adds new features, particularly making configspec handling more flexible. Full details on the changes can be found at: http://www.voidspace.org.uk/python/weblog/arch_d7_2009_04_11.shtml#e1078 The changelog for ConfigObj 4.6.0 is: * Pickling of ConfigObj instances now supported (thanks to Christian Heimes) * Hashes in confgspecs are now allowed (see note below) * Replaced use of hasattr (which can swallow exceptions) with getattr * ``__many__`` in configspecs can refer to scalars (ordinary values) as well as sections * You can use ``___many___`` (three underscores!) where you want to use ``__many__`` as well * You can now have normal sections inside configspec sections that use ``__many__`` * You can now create an empty ConfigObj with a configspec, programmatically set values and then validate * A section that was supplied as a value (or vice-versa) in the actual config file would cause an exception during validation (the config file is still broken of course, but it is now handled gracefully) * Added ``as_list`` method * Removed the deprecated ``istrue``, ``encode`` and ``decode`` methods * Running test_configobj.py now also runs the doctests in the configobj module * Through the use of validate 1.0.0 ConfigObj can now validate multi- line values As the public API for Validate is stable, and there are no outstanding issues or feature requests, I've bumped the version number to 1.0.0. The full change log is: * BUGFIX: can now handle multiline strings * Addition of 'force_list' validation option -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: Domain Driven Design and Python
José María wrote: DDD is more or less a methodology. I've used it with C# and I like it very much. The objetive of DDD is to create software that mirror the domain of the problem, you isolate this domain from the technical problems (persistence, services,GUI). I presume that many Python programmers do this without calling it 'DDD'. -- http://mail.python.org/mailman/listinfo/python-list
Re: question about xrange performance
Paul McGuire: xrange is not really intended for in testing, Let's add the semantic of a good and fast in to xrange (and to the range of Python3). It hurts no one, allows for a natural idiom (especially when you have a stride you don't want to re-invent the logic of skipping absent numbers), and it's readable. My xrange() I have written in D language has a fast OpIn_r() method. I haven't found any bad side effect to such capability yet. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: Beginner: Portable Python, BeautifulSoup ScrapeNFeed
Was this code a complete waste of my time?
On Wed, Apr 15, 2009 at 1:09 AM, Brian brian.min...@colorado.edu wrote:
On Ubuntu:
sudo apt-get install python-pyrss2gen python-beautifulsoup # download
ScrapeNFeed
Python:
Not sure what's wrong with this but it's most of the code you'll need:
---
from urllib import urlopen
from BeautifulSoup import BeautifulSoup
from PyRSS2Gen import RSSItem, Guid
import ScrapeNFeed
import re
url='http://jobs.spb.ca.gov/exams_title.cfm'
job_html = urlopen(url).read()
job_soup = BeautifulSoup(job_html)
jobs = job_soup.findAll('strong', text=re.compile('.*RESEARCH.*'))
class JobFeed(ScrapeNFeed.ScrapedFeed):
def HTML2RSS(self, headers, body):
items = [RSSItem(title=job,
link=url,
description=job_soup.h2.string.strip())
for job in jobs]
self.addRSSItems(jobs)
JobFeed.load(job_soup.title.string.strip(),
url,
'jobs.rss',
'jobs.pickle',
managingEditor='',
)
On Tue, Apr 14, 2009 at 4:17 PM, Joe Larson j...@joelarson.com wrote:
Hello list!
I am a Python Beginner. I thought a good beginning project would be to use
the Portable Python environment http://www.portablepython.com/ with
Beautiful Soup http://www.crummy.com/software/BeautifulSoup/ and Scrape
'N' Feed http://www.crummy.com/software/ScrapeNFeed/ to create and RSS
feed of this page http://jobs.spb.ca.gov/exams_title.cfm - ideally
filtering just for positions with the string 'Research Analyst'.
In my day job I work on the Windows OS (hence the Portable Python) - at
home I use Ubuntu but also carry Portable Ubuntu as well.
I just wanted to shoot this to the list - see if anyone had any
suggestions or tips. I'm reading O'Reilly's Learning Python and The Python
Tutorial, but it's still very challenging as this is my first programming
language. Thanks all! Sincerely ~ joelar
--
http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
Re: Question to python C API
Andreas Otto wrote: just my first step in Cython 1. download Cython-0.11.1 2. read INSTALL.txt (1) Run the setup.py script in this directory as follows: python setup.py install This will install the Pyrex package into your Python system. Question 1: Why you wall it Pyrex package ? That's a left-over. We fixed the name almost everywhere by now, but that slipped through. That shows that the installation instructions haven't been touched in years (although they should work in general). 3. this happen python ./setup.py install Traceback (most recent call last): File ./setup.py, line 5, in module from Cython.Compiler.Version import version File /home/dev1usr/src/Cython-0.11.1/Cython/__init__.py, line 2, in module from Shadow import * ImportError: No module named Shadow Relative imports have changed in Py3, so as you write: 4. I use a thread enabled python V3 That's the core problem. :) Like many other Python packages, Cython doesn't currently run in Py3. You can run it in any Py2 version starting from 2.3, and the code it generates will run on 2.3 through 3.1a1. But the Cython compiler itself requires 2.x. This is being fixed up as we speak, and the 2to3 conversion tool works pretty well on the source by now, so there's a fair chance that Cython 0.12 will run on Py3. Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
On Fri, 17 Apr 2009 22:26:32 -0700, norseman wrote: The average programmer, who takes a moment to think it out, A moment? As in, a second or less? can out optimize all but the best commercial compilers. The meticulous individual can usually match or best the best commercials with fewer 'iterations' of review when using assembly. That might have been true in the 1970s and 80s, but it hasn't been true for 10-20 years now. The best machine-optimized code is significantly better than the best human beings can do today, and even free optimizing compilers can do better than most people. However, human programmers can, sometimes, hand-optimize the output of the optimizing compiler in order to gain a slight upper-hand. To paraphrase Charles Fiterman, the human should always win, because the human can use the machine, but the machine can't use the human. http://www.linux.com/base/ldp/howto/Assembly-HOWTO/howtonot.html Since one is already looking at the registers and addresses, self optimization is simple. If only modern day programming was that simple. The interaction with modern CPU makes optimization an order of magnitude harder than it was back in the days of hand-tuned assembly. I quote from the above link: The biggest problems on modern architectures with fast processors are due to delays from memory access, cache-misses, TLB-misses, and page- faults; register optimization becomes useless, and you'll more profitably re-think data structures and threading to achieve better locality in memory access. Toto-I-don't-think-we're-in-1975-anymore-ly y'rs, -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Suggestions wanted on Tkinter problem
On Thu, 16 Apr 2009 16:18:03 -0700, norseman wrote: At this point the program runs, but I cannot control gray-out of a specific Radiobutton. If I: counter=0 for mode, text c[counter] = Radiobuton(specified_frame,.. c[counter].pack() counter += 1 . . blockUseOf= $varSetElsewhere What language are you programming in? $varSetElsewhere isn't legal Python. c[blockUseOf].config(state = strSetElsewhere) Program crashes on Radiobutton line. No no, don't tell us *what* error you got! We LOVE guessing games!!! Hmm, this guessing game might be harder than I like. Not only aren't we told what the error is, but half of the line that contains the error is a secret. How about telling us what the actual error is, and the actual line that causes the error? Chances are very good that the error message will tell you everything you need to know about why the program fails. There are a number of Frames containing Radiobuttons in the program. The individual lists are long enough no one in their right mind wants to hand code such repetition and then try to maintain it. Then perhaps you should think about changing the user interface to make it simpler to manage, and simpler to use. Not every task requires a hammer. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
On Fri, 17 Apr 2009 20:45:30 -0700, Mensanator wrote: Nevertheless, somebody *has* implemented such functionality in Python. Not just GOTO, but also COMEFROM. Really? Well, _I_ for one, won't be beating a path to his door. Well you should. It's very clever code, and the way he solved the problem is intriguing. It was also a great April Fools joke. For reference, here's that URL again: http://entrian.com/goto/ GOTO in Pascal required that you defined a label in your code, then you could jump to that label. You can't jump to arbitrary parts of the program, only within the current procedure. And I deliberately made no effort to learn how to use them. And I never had a situation I couldn't solve the proper way. You need to distinguish between the use of unstructured jumps like Basic- style GOTOs and COMEFROMs, which can jump anywhere, and the use of structured GOTOs and jumps that have well-defined meanings. GOTO, after all, is just a jump, and we use jumps in Python all the time: raise Exception break continue if... elif... else... for... else... etc. Often -- well, sometimes -- you can write cleaner, simpler code with GOTO than without. Fortunately, 95% of those cases can be dealt with a break or continue in a loop. In a high level language, GOTO is never necessary and rarely useful, but it is useful on occasion. Any time you find yourself creating a flag variable just so you can skip a code block, or enter a code block, then a structured GOTO *could* be a clean replacement. But probably isn't. (This is not a call for Python to develop a GOTO, just a defence that they aren't always the Wrong Thing.) COMEFROM on the other hand is just the purest evil imaginable. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: script question
pyt...@bdurham.com wrote: Peter, Another eval-free variant: [x() for x in vars().values() if hasattr(x, _included)] If you use getattr(x, _included, False) instead of hasattr() you can un-include functions with ... YES! That's what I was struggling to do with my in-elegant use of eval(), eg. replacing eval() to expand dir() strings with a dictionary of local objects. Question: why vars() vs. globals()? My tests in IDLE (Python 2.6) show vars() and globals() returning the same items. Indeed, it doesn't matter here. I chose vars() because it uses the same logic as dir(), i. e. vars().keys() should give you the same names as dir(). Note that both vars() and dir() give you the same namespace as locals() which just happens to be the same as globals() on the module level. Inside a function you have to use globals() or vars(module) to access the module's global namespace. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Registering Cron using CronTab
On Apr 18, 5:21 am, Lawrence D'Oliveiro l...@geek- central.gen.new_zealand wrote: In message mailman.4054.1239976986.11746.python-l...@python.org, Philip Semanchuk wrote: On Apr 17, 2009, at 9:51 AM,gurcharan.sa...@gmail.com wrote: I'm stuck with the issue - if we execute the code from Apache the crontab is not getting updated, while it get updated if we run it from Django in-built webserver. Sure sounds like a permissions problem to me. Same here. Note that you can run a CGI under its owning user in Apache with the suexec feature. That might give you the permissions you need. Thanks, will go through the docs. -- http://mail.python.org/mailman/listinfo/python-list
Re: binary file compare...
Adam Olsen rha...@gmail.com (AO) wrote: AO The Wayback Machine has 150 billion pages, so 2**37. Google's index AO is a bit larger at over a trillion pages, so 2**40. A little closer AO than I'd like, but that's still 56294995000 to 1 odds of having AO *any* collisions between *any* of the files. Step up to SHA-256 and AO it becomes 1915619400 to AO 1. Sadly, I can't even give you the odds for SHA-512, Qalculate AO considers that too close to infinite to display. :) AO You should worry more about your head spontaneously exploding than you AO should about a hash collision on that scale. To do otherwise is AO irrational paranoia. And that is the probability if there being two files in that huge collection with the same hash. If you just take two files, not fabricated to collide, the probability of them having the same hash under MD5 is 2**-128 which I think is way smaller than the probability of the bit representing the answer being swapped by some physical cause in your computer. But then again, it doesn't make sense to use that instead of byte-by-byte comparison if the files are on the same machine. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Question to python C API
Andreas Otto aotto1...@onlinehome.de wrote about his attempts to install and run Cython: 5. and start to build the hello world example I changed: print Hello World to: print(Hello World)- this is V3 AFAIK Cython doesn't support Python 3, yet. See http://trac.cython.org/cython_trac/ticket/234 I suggest staying with Python 2.x. What C compiler are you going to use, btw.? -- Wir danken für die Beachtung aller Sicherheitsbestimmungen -- http://mail.python.org/mailman/listinfo/python-list
Re: Play sound at wanted frequency
On 15 Apr, 19:25, Scott David Daniels scott.dani...@acm.org wrote: Diez B. Roggisch wrote: Matteo schrieb: I need to playback a sound on a linux machine of a pre-determined frequency like, say, 440 Hz. How can I do that with python? I found the ossaudiodev package, but it says that the ossaudiodev.write() method accepts data as a raw string. It doesn't explain what the string should be like, and the oss documentation is mainly about C++. Do you have any tips to share? Try pygame. You can create samples with it, and play them. See e.g. this:http://www.pygame.org/docs/ref/sndarray.html And realize that if you can get that to work, you can always cut into pygame to see how _it_ accomplishes your task, and mimic that. --Scott David Daniels scott.dani...@acm.org I'll give it a try, thanks ;) -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
stephane.bisin...@gmail.com (SB) wrote: SB Hi all, SB I have a problem with Condition.wait(), it doesn't return after the SB given timeout. The thing is that if I try to create a simple program, SB it works as expected, but in the actual code, the timeout is not SB respected (albeit the notify()s work as expected). SB You can find the code I am talking about here: SB http://github.com/Kjir/amsn2/blob/6688da4c0b7cc16c0fe04d6d6018bc1b16d992a6/amsn2/gui/front_ends/curses/contact_list.py SB If you clone the repository, then you can run the program like this: SB $ python amsn2.py -f curses 2 run.log SB and in another term watch for prints with a tail -f run.log (You need SB an MSN account). You'll notice that after the initial downloading of SB the contact list, there won't be any logs (unless some of your SB contacts changes status, which will trigger a notify) SB Has anyone the slightest idea on what I may be doing wrong? Or am I SB just lucky enough to have stumbled across a bug? Maybe pollution from SB another module in other parts of the code? (Like gobject...) I haven't run it (too much hassle to setup) but I noticed one strange thing in your code: , | def groupUpdated(self, gView): | # Acquire the lock to do modifications | self._mod_lock.acquire() | | if not self._groups.has_key(gView.uid): | return ` In case the return is taken, the lock will not be released thereby blocking the rest. It could be that the timeout is taken, but before the wait can continue it has to acquire the lock again. It is best to put all your code after the acquire in a try: finally: like , | self._mod_lock.acquire() | try: | do something | finally: | self._mod_lock.release() ` or even better use the with statement: , | with self._mod_lock: | do something ` It will do the releasing automatically And then something else: , | def __thread_run(self): |while True: |import sys |print sys.stderr, at loop start |self._mod_lock.acquire() |t = time.time() |# We don't want to work before at least half a second has passed |while time.time() - t 0.5 or not self._modified: |print sys.stderr, Going to sleep\n |self._mod_lock.wait(timeout=1) |print sys.stderr, Ok time to see if we must repaint |self.__repaint() |t = time.time() |self._mod_lock.release() |print sys.stderr, at loop end |self._mod_lock.acquire() ` Your loop ends with self._mod_lock.acquire() but in the next round there is another self._mod_lock.acquire() at the beginning of the loop. So the acquire at the end isn't necessary. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python andBasic?
baykus b..@gmail.com wrote: I guess I did not articulate myself well enough. I was just looking for a toy to play around. I never suggested that Python+Basic would be better than Python and everyone should use it. Python is Python and Basic is Basic. I am not comparing them at all. I understand the merits of Python but that does not mean I can play with ideas? Apparently this is not allowed by the CS thought police. The reasoning is based on an Argument from Authority, namely the Dijkstra link. Now it looks to me when I read that article, that the jump is deprecated because it leads to code that is difficult to understand, which was based on the difficulty that Dijkstra had to construct a co-ordinate system for storing the state of a program at any given line of code. This was done without giving any reason as to why this should be important, or even desirable, except towards the end where he wanted to define instances in time when a count could conceivably be off by one, and he asserted without proof that having jumps in the code makes this more difficult. Even if this assertion were to be provably true, it does not really follow that jumps should be banned, but merely that one runs such a risk if one were to use them. Now to some minds, this difficulty may not be a difficulty at all: Processors and interrupt service routines are storing the state of multiple programmes at arbitrary points in the code, even as I type - and every one of those programmes include jumps. It is a non - issue. Mensanator had the same complaint based on difficulty earlier in this thread, when he described how he struggled to untangle some spaghetti code. He did not mention if the spaghetti was actually doing it's job, bug free, which IMO is the only rational test for the quality of a piece of code, because it is the reason for its existence. The aesthetics are, like all aesthetics, a matter of opinion. I do not agree with the reasoning that effectively says: If it is difficult to comprehend, it must be wrong If this were to be a tenet, then using the pickle module should be forbidden too, as it is a complex piece of code that (to me at least) is not easily understood on a first read-through. So does that mean I must stop using pickles? All Strength to Arnaud for his goto code! I am looking forward to the gosub and return. :-) - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Re: send() to a generator in a for loop with continue(val)??
Dale Roberts wrote: I've started using generators for some real work (love them!), and I need to use send() to send values back into the yield inside the generator. When I want to use the generator, though, I have to essentially duplicate the machinery of a for loop, because the for loop does not have a mechanism to send into the generator. Here is a toy example: def TestGen1(): for i in xrange(3): sendval = yield i printgot %s in TestGen() % sendval g = TestGen1() sendval = None try: while True: val = g.send(sendval) print 'val in while loop %d' % val sendval = val * 10 except StopIteration: pass I have to explicitly create the generator with an assignment, send an initial None to the generator on the first go, then have to catch the StopIteration exception. In other words, replicate the for mechanism, but use send() instead of next(). It would be nice if I could just do this instead: for val in TestGen1(): print 'val in for loop %d' % val continue(val*10) ...or something similar. Is this an old idea? Has it been shot down in the past already? Or is it worth pursuing? I Googled around and saw one hit here: http://mail.python.org/pipermail/python-ideas/2009-February/003111.html, but not much follow-up. I wonder if people want to keep the idea of an iterator style generator (where send() is not used) separate from the idea of a co- routine style generator (where send() is used). Maybe combining the two idioms in this way would cause confusion? What do folks think? If it were up to me I'd rip out send() immediatly. At first I thought I would see a compelling use case and be enlightened, but it never happened. I just grepped the python 3 source for '= yield' and the only matches were in the unit tests for generators and parser. Let it die while it hasn't polluted the wider code base. Peter -- http://mail.python.org/mailman/listinfo/python-list
pyqt4 qTableWidget add items help
I've been searching around the internet for an example of how to add a list of items to the qTableWidget for the last few hours with little success. I have a list orders [[34,940,30,50,67], [50,56,35,30,57]] as my example here I built the qTableWidget in designer, so it already has the header columns filled out. Date | time | Number | Price | Buyer ui.tb1_tblOrders.setRowCount(len(orders)) gives me the correct number of rows I want, but how do I fill the rows? I've been trying while(len(orders) i): ui.tb1_tblOrders.setCurrentCell(i,0,orders[i][1]) i+=1 which to me, says go add in the first column row with the first order, and it makes sense to me It just says Error: argument 3 of QTableWidget.setCurrenCell() has invalid type, I know it's the orders, but I can't figure out what the proper way of giving it what it wants is. -- http://mail.python.org/mailman/listinfo/python-list
Re: pyqt4 qTableWidget add items help
ookrin schrieb: I've been searching around the internet for an example of how to add a list of items to the qTableWidget for the last few hours with little success. I have a list orders [[34,940,30,50,67], [50,56,35,30,57]] as my example here I built the qTableWidget in designer, so it already has the header columns filled out. Date | time | Number | Price | Buyer ui.tb1_tblOrders.setRowCount(len(orders)) gives me the correct number of rows I want, but how do I fill the rows? I've been trying while(len(orders) i): ui.tb1_tblOrders.setCurrentCell(i,0,orders[i][1]) i+=1 which to me, says go add in the first column row with the first order, and it makes sense to me It just says Error: argument 3 of QTableWidget.setCurrenCell() has invalid type, I know it's the orders, but I can't figure out what the proper way of giving it what it wants is. I don't find setCurrentCell in the docs for QTableWidget - only for Q3Table. http://doc.trolltech.com/4.0/q3table.html#setCurrentCell However, that call isn't about setting the value of a cell, instead it's about giving a cell the focus. Use setItem instead. And don't use the wicked while-loop for generating indices - this is done in python using the enumerate-function: for i, order in enumerate(orders): ... Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: pyqt4 qTableWidget add items help
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 ookrin – Samstag, 18. April 2009 11:58 [...] I've been trying while(len(orders) i): ui.tb1_tblOrders.setCurrentCell(i,0,orders[i][1]) i+=1 which to me, says go add in the first column row with the first order, and it makes sense to me Read the documentation [1] to learn, what .setCurrentCell() actually does and what its arguments are! And please stop this wild guessing ... The method you're searching for is .setItem() [2], which adds a new QTableWidgetItem [3] to a QTableWidget. [1] http://doc.trolltech.com/4.5/qtablewidget.html#setCurrentCell [2] http://doc.trolltech.com/4.5/qtablewidget.html#setItem [3] http://doc.trolltech.com/4.5/qtablewidgetitem.html - -- Freedom is always the freedom of dissenters. (Rosa Luxemburg) -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.11 (GNU/Linux) iEYEARECAAYFAknpr4sACgkQGV4vxEMMOxdnawCfTXO55EffBJMQ7h91RGtMIpZ/ hcYAoLQ9yF5u/hBgNRvqxGRlIy5lPDgb =Q6ef -END PGP SIGNATURE- -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python andBasic?
On Apr 18, 4:44 am, Hendrik van Rooyen m...@microcorp.co.za wrote: baykus b..@gmail.com wrote: I guess I did not articulate myself well enough. I was just looking for a toy to play around. I never suggested that Python+Basic would be better than Python and everyone should use it. Python is Python and Basic is Basic. I am not comparing them at all. I understand the merits of Python but that does not mean I can play with ideas? Apparently this is not allowed by the CS thought police. The reasoning is based on an Argument from Authority, namely the Dijkstra link. Boo, Appeal to Authority! snip to untangle some spaghetti code. He did not mention if the spaghetti was actually doing it's job, bug free, which IMO is the only rational test for the quality of a piece I don't use 'rational' in the same way. Do you mean objective? Do readability, brevity, simplicity, purity, etc. contribute to quality? Is program quality equivalent (or identical) to code quality? of code, because it is the reason for its existence. The aesthetics are, like all aesthetics, a matter of opinion. I do not agree with the reasoning that effectively says: If it is difficult to comprehend, it must be wrong Wrong no, but impractical, possibly or probably or almost certainly, notwithstanding the subject-dependence of ease of comprehension. Simple code is more future-resilient than that which is difficult to comprehend, even holding the language (version) constant. It is a matter of priorities, which have no objective right. The amount of people that can comprehend a code structure is a competing value to that of exploration, pioneering, research, and development. However, even in simplest terms, some structures e.g. recursion, may be difficult to comprehend, but that doesn't mean they would be better more complicated. -- http://mail.python.org/mailman/listinfo/python-list
Re: question about xrange performance
On Fri, 17 Apr 2009 23:40:32 -0700 (PDT) bearophileh...@lycos.com wrote: Paul McGuire: xrange is not really intended for in testing, Let's add the semantic of a good and fast in to xrange (and to the range of Python3). It hurts no one, allows for a natural idiom (especially when you have a stride you don't want to re-invent the logic of skipping absent numbers), and it's readable. A fast in to xrange would be great. Why was it taken away? -- http://mail.python.org/mailman/listinfo/python-list
Re: Modifying the value of a float-like object
On Apr 15, 5:33 pm, Arnaud Delobelle arno...@googlemail.com wrote: I still don't think mutable floats are necessary. Here is an approach below - I'll let the code speak because I have to do some shopping! Hats off to you, Arnaud! I'm very impressed by the ideas found in your code. :) Your UExpr object is almost a mutable float, though (x=UVal(...); y=x; x.value =...; print y+0 gives a new value). What was not needed was some kind of external access to numbers with error, that would have allowed an external routine to modify them so as to perform calculations of Python expressions with different parameters. Your idea of building an expression (UExpr) that keeps track of the variables involved in it (basis) was great! I was somehow stuck with the idea that float with uncertainty objects should return a float, when involved in mathematical calculations. I adjusted your code in a few ways, and put the result at http://code.activestate.com/recipes/576721/ (with due credit): 1) There was a strange behavior, which is fixed (by performing only dynamic calculations of UExpr, with an optimization through a new constant class): x = UVal(100., 1.) y = 2*x x.value = 3.14 print y, should equal, y+0 # Values not equal! 200.0 +- 2.06348273 should equal 6.2802 +- 2.00131024 2) More operations are supported: calculations with integers (UVal (1)), comparisons, unary operators + and - (+Uval(1.)),... 3) The code is documented, and identifiers are longer and more explicit. Voilà! Thank you all for this lively and productive thread! -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
Steven D'Aprano wrote: To paraphrase Charles Fiterman, the human should always win, because the human can use the machine, but the machine can't use the human. Unless the machine is Omnius. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
I first started programming basic and i don't think it has hurt me much. I can somewhat sympathise with the op, neither python nor any other mainstream language can still do this: SCREEN 13 PSET 160,100,255 2009/4/17, Leguia, Tony legui...@grinnell.edu: Though I don't know why you would want to reference lines numbers, I assume it's for goto statements or something similar. With that said please read: 1) http://www.u.arizona.edu/~rubinson/copyright_violations/Go_To_Considered_Harmful.html I would also like to put forth my opinion, shared by many in the community, that Basic is actually dangerous as an educational programming language, and that writing large professional code in it is hard, and actually hampered by the language. I'm not trying to to start a flame war here but this post almost made me cry. Also python is functional, it's so powerful. Grow and learn to take advantage of that. Why hold yourself back? From: python-list-bounces+leguiato=grinnell@python.org [python-list-bounces+leguiato=grinnell@python.org] On Behalf Of baykus [baykusde...@gmail.com] Sent: Friday, April 17, 2009 3:37 PM To: python-list@python.org Subject: Is there a programming language that is combination of Python and Basic? Hi I am looking for one of those experimental languages that might be combination of python+basic. Now thta sounds weird and awkward I know. The reason I am asking is that I always liked how I could reference- call certain line number back in the days. It would be interesting to get similar functionality in Python. -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list -- mvh Björn -- http://mail.python.org/mailman/listinfo/python-list
Too early implementation
I am not a very disciplined person. Usually I rush to my next assignment and code furiously, hoping that my initial understanding of the stated problem will be just fine. And Python does very little to stop me ;-) If I had to do something in C++, I know I would have to write all those header files, fill stubs, etc., which is a lot of work, which I don't want to do twice. So I take a while and start to think, because it's better to be safe, than sorry. With Python you rarely are sorry, because you can do everything so quickly. And yet, at some point you see, that flaws in design get so annoying, that you need to do something about them. Usually at that point it's a bit problematic ;-) So, do you know some good methods to prevent myself from just starting coding (which I like very much) and do some thinking about the problem (which I like a little less ;-))? -- Filip Gruszczyński -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
On Apr 18, 10:24 am, Piet van Oostrum p...@cs.uu.nl wrote: I haven't run it (too much hassle to setup) but I noticed one strange thing in your code: , | def groupUpdated(self, gView): | # Acquire the lock to do modifications | self._mod_lock.acquire() | | if not self._groups.has_key(gView.uid): | return ` In case the return is taken, the lock will not be released thereby blocking the rest. It could be that the timeout is taken, but before the wait can continue it has to acquire the lock again. That is absolutely correct, but I guess with an RLock there shouldn't be a deadlock... Anyway I'm fixing that! It is best to put all your code after the acquire in a try: finally: like , | self._mod_lock.acquire() | try: | do something | finally: | self._mod_lock.release() ` or even better use the with statement: , | with self._mod_lock: | do something ` It will do the releasing automatically Thanks for the advice! And then something else: , | def __thread_run(self): | while True: | import sys | print sys.stderr, at loop start | self._mod_lock.acquire() | t = time.time() | # We don't want to work before at least half a second has passed | while time.time() - t 0.5 or not self._modified: | print sys.stderr, Going to sleep\n | self._mod_lock.wait(timeout=1) | print sys.stderr, Ok time to see if we must repaint | self.__repaint() | t = time.time() | self._mod_lock.release() | print sys.stderr, at loop end | self._mod_lock.acquire() ` Your loop ends with self._mod_lock.acquire() but in the next round there is another self._mod_lock.acquire() at the beginning of the loop. So the acquire at the end isn't necessary. I have no idea how that came to be, probably pasted one line where I shouldn't have, it's gone ;) Anyway I cleaned up that mess and here is the resulting code, with the same issues: http://github.com/Kjir/amsn2/commit/bda6829d0c7d50a1cbf1188cdfa3789c4b7967c5 http://github.com/Kjir/amsn2/blob/bda6829d0c7d50a1cbf1188cdfa3789c4b7967c5/amsn2/gui/front_ends/curses/contact_list.py I'll also file a bug report because I am more and more convinced this is a bug, if anything else at least in the documentation... -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
Filip Gruszczyński wrote: I am not a very disciplined person. Usually I rush to my next assignment and code furiously, hoping that my initial understanding of the stated problem will be just fine. And Python does very little to stop me ;-) If I had to do something in C++, I know I would have to write all those header files, fill stubs, etc., which is a lot of work, which I don't want to do twice. So I take a while and start to think, because it's better to be safe, than sorry. So, do you know some good methods to prevent myself from just starting coding (which I like very much) and do some thinking about the problem (which I like a little less ;-))? Well, you can force yourself to write tests first... -tkc -- http://mail.python.org/mailman/listinfo/python-list
any complete and actual pysqlite example?
I mean not a code to do seperated functions, but a real project I have read the doc of pysqlite, but since I know little about database, I found it is still very hard for me to cook a real database app from the scratch with the help of codelet in pysqlite doc. here is the simplified details: [TABLE 1] bookName text price num author -- this is actually linked with the [TABLE 2], for one author maybe write many books, I think it is better to do an external link [/TABLE 1] [TABLE 2] authorName text [/TABLE 2] Then [record for TABLE 1] id bookName price authoridx 1 The Definitive Guide to SQLite 30 1 2 Core Python 40 2 3 Dive Into Python35 3 [/record for TABLE 1] [record for TABLE 2] id authorName 1 Michael Owens 2 Wesley J. Chun 3 Mark Pilgrim [/record for TABLE 2] what I need 1. of cause, create the TABLE, and add real data into it. I don't know how to deal with the author item in [TABLE 1] 2. list the data. A question is, when I list the record in [TABLE 1], can I get something like following? The Definitive Guide to SQLite, 30.0, Michael Owens I mean, the authorName is returned automatically, but not only the authoridx 3. what if I del the 1st record in [TABLE 2] since a record in [TABLE 1] use it? 4.I want to do some group, for example, group the record in [TABLE 1] according to their price, so that [30] Book1Name Book2Name [40] Book3Name [50] Book4Name Book4Name does sqlite support this? or I have to do this in python? thanx -- http://mail.python.org/mailman/listinfo/python-list
Re: can't install new modules after updating python
In article f2a25d72-5e21-498a-95a4-59045f158...@r37g2000yqn.googlegroups.com, lie liewai...@gmail.com wrote: I've updated from python 2.5 to 2.6 on my Slackware 12.2, by compiling the 2.6 source. When I try to use slapt-get to install a new module for python, it installs in the old version, and I can't use it. How can I fix this? Should I go back to 2.5? Generally speaking, you should never directly update the system Python; most Linux systems these days rely on Python for their operation. Instead, you install an additional copy of Python, and you cannot use your OS package management to install modules; just install the modules manually. -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: send() to a generator in a for loop with continue(val)??
In article gsc7e1$rj6$0...@news.t-online.com, Peter Otten __pete...@web.de wrote: If it were up to me I'd rip out send() immediatly. At first I thought I would see a compelling use case and be enlightened, but it never happened. Too late -- it's likely to get an upgrade for 3.1 and 2.7. Basically, send() is useful for coroutines, and if you haven't yet read http://dabeaz.com/coroutines/ you really should (assuming you want to continue arguing). -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
In article 1eb44e98-3f32-42b3-92f8-1e635428c...@q9g2000yqc.googlegroups.com, stephane.bisin...@gmail.com wrote: I have a problem with Condition.wait(), it doesn't return after the given timeout. The thing is that if I try to create a simple program, it works as expected, but in the actual code, the timeout is not respected (albeit the notify()s work as expected). Whether or not there's a bug, you likely will simplify your code if you switch to using a Queue(). -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
On Apr 18, 2:05 pm, a...@pythoncraft.com (Aahz) wrote: Whether or not there's a bug, you likely will simplify your code if you switch to using a Queue(). I'm sorry, but I can't see how the queue would help me on this, since I only have 2 threads and the documentation esplicitly states that it helps with multiple threads. I have no items to put in the queue, my only concern is not to update the screen while I am changing the state of the contact list... Maybe there's something I didn't think of, but I'd need more details on your part if that is the case, because I really can't see the advantage of Queue in this situation... Thanks, Stéphane -- http://mail.python.org/mailman/listinfo/python-list
Re: question about xrange performance
[soapbox] Speaking about idiomacy, ... [end soapbox] soapbox] I ALREADY STEPPED DOWN FROM SOAPBOX (on this topic) [end soapbox] thanks for the comment anyhow. that an efficient `x in y` implementation used to be there and is gone now is gross. guess i'll just have to live with my own makeshift implementation. gross. cheers -- http://mail.python.org/mailman/listinfo/python-list
Re: send() to a generator in a for loop with continue(val)??
On Apr 18, 3:03 pm, a...@pythoncraft.com (Aahz) wrote: In article gsc7e1$rj6$0...@news.t-online.com, Peter Otten __pete...@web.de wrote: If it were up to me I'd rip out send() immediatly. At first I thought I would see a compelling use case and be enlightened, but it never happened. Too late -- it's likely to get an upgrade for 3.1 and 2.7. Basically, send() is useful for coroutines, and if you haven't yet readhttp://dabeaz.com/coroutines/ you really should (assuming you want to continue arguing). -- I suspect Peter knows everything about coroutines and still he is not convinced about .send. FWIW, I am sympathic with him. M. Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
On Apr 18, 9:48 pm, Filip Gruszczyński grusz...@gmail.com wrote: With Python you rarely are sorry, because you can do everything so quickly. And yet, at some point you see, that flaws in design get so annoying, that you need to do something about them. Usually at that point it's a bit problematic ;-) So, do you know some good methods to prevent myself from just starting coding (which I like very much) and do some thinking about the problem (which I like a little less ;-))? Try test-driven development: http://en.wikipedia.org/wiki/Test-driven_development -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
BJörn Lindqvist wrote: I first started programming basic and i don't think it has hurt me much. I can somewhat sympathise with the op, neither python nor any other mainstream language can still do this: SCREEN 13 PSET 160,100,255 Maybe, who is able to understand such nosense without a lot of apriori knowledge ? cheers, Stef -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
On Apr 18, 12:48 pm, Filip Gruszczyński grusz...@gmail.com wrote: So, do you know some good methods to prevent myself from just starting coding (which I like very much) and do some thinking about the problem (which I like a little less ;-))? Well you know, the thing is that according to Pike Kernighan in The Practice of Programming, your first implementation of a program should be scrapped and rewritten from scratch, so your approach might not be that wrong after all. The trouble is that if you overthink your code, you'll end up losing interest in the project and write bloated code that may be too generic for what you need. So either way there can be trouble, although it is right to try to balance yourself in between these two extremes... -- http://mail.python.org/mailman/listinfo/python-list
Re: Your confirmation is required to join the Python-list mailing list
Hello. i was wondering if there would be someone on the list that know of or have ideas for a beginner python project ? i have made a simple calculator Program with a if else loop. and such. but i need a new project. i know xml. html. css. and a bit JavaScript. so it can incorporate any or all of those languages. Any help / ideas are very much appreciated. /mads -- http://mail.python.org/mailman/listinfo/python-list
Re: can't install new modules after updating python
On Apr 18, 9:00 am, a...@pythoncraft.com (Aahz) wrote: In article f2a25d72-5e21-498a-95a4-59045f158...@r37g2000yqn.googlegroups.com, Generally speaking, you should never directly update the system Python; most Linux systems these days rely on Python for their operation. Instead, you install an additional copy of Python, and you cannot use your OS package management to install modules; just install the modules manually. Agreed. I tend to keep my own Python installation in ~/opt, and then use the usual `python setup.py install` to install modules. You just need to make sure you have $HOME/opt/py/bin in your $PATH before the system python (or else explicitly specify `~/opt/py/bin/python setup.py install` when you install modules). If your *system* Python needs modules, you install those with your OS package management utility. -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
Steven D'Aprano wrote: On Fri, 17 Apr 2009 14:00:18 -0700, Mensanator wrote: On Apr 17, 3:37 pm, baykus baykusde...@gmail.com wrote: Hi I am looking for one of those experimental languages that might be combination of python+basic. Now thta sounds weird and awkward I know. That's a clue you won't find anyone seriously contemplating such idiocy. The reason I am asking is that I always liked how I could reference- call certain line number back in the days. A bad idea. If you really want to write bad code, learn C. It would be interesting to get similar functionality in Python. Yeah, it would interesting just as a train wreck is interesting, as long as you're not the one who has to live through it. Nevertheless, somebody *has* implemented such functionality in Python. Not just GOTO, but also COMEFROM. http://entrian.com/goto/ I once translated a BASIC program to Pascal (hint: no goto allowed). Pascal has GOTOs. People rarely used them, because even in the 1970s and 80s they knew that unstructured gotos to arbitrary places was a terrible idea. GOTO in Pascal required that you defined a label in your code, then you could jump to that label. You can't jump to arbitrary parts of the program, only within the current procedure. What I found strange was that labels could be only unsigned integers, but they still had to be declared: label 1, 2, 3; Fortunately the version(s) I used (TurboPascal/Dephi) permitted identifiers. -- http://mail.python.org/mailman/listinfo/python-list
Re: class variables and class methods
In article 9c848013-2245-455e-bb30-48e430d56...@j9g2000prh.googlegroups.com, krishnaposti...@gmail.com wrote: I have a class whose job is to serve several other objects, [...] Sorry, I'm finding it difficult to understand what you want. It looks to me that you're confusing object and instance, and I think you're also confusing variable and attribute. You might find it helpful to read the following URLs and then re-post with new phrasing: http://docs.python.org/tutorial/classes.html http://starship.python.net/crew/mwh/hacks/objectthink.html http://effbot.org/zone/python-objects.htm -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: send() to a generator in a for loop with continue(val)??
In article 07ad771b-a6d1-4f08-b16c-07caf7462...@e18g2000yqo.googlegroups.com, Michele Simionato michele.simion...@gmail.com wrote: On Apr 18, 3:03=A0pm, a...@pythoncraft.com (Aahz) wrote: In article gsc7e1$rj6$0...@news.t-online.com, Peter Otten =A0__pete...@web.de wrote: If it were up to me I'd rip out send() immediatly. At first I thought I would see a compelling use case and be enlightened, but it never happened. Too late -- it's likely to get an upgrade for 3.1 and 2.7. Basically, send() is useful for coroutines, and if you haven't yet read http://dabeaz.com/coroutines/ you really should (assuming you want to continue arguing). I suspect Peter knows everything about coroutines and still he is not convinced about .send. FWIW, I am sympathic with him. Okay, I'm curious, is the argument that you shouldn't use generators for coroutines or something else? -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
In article 8373c927-5ef2-4511-a439-25caa3fd6...@v15g2000yqn.googlegroups.com, stephane.bisin...@gmail.com wrote: On Apr 18, 2:05=A0pm, a...@pythoncraft.com (Aahz) wrote: Whether or not there's a bug, you likely will simplify your code if you switch to using a Queue(). I'm sorry, but I can't see how the queue would help me on this, since I only have 2 threads and the documentation esplicitly states that it helps with multiple threads. I have no items to put in the queue, my only concern is not to update the screen while I am changing the state of the contact list... Maybe there's something I didn't think of, but I'd need more details on your part if that is the case, because I really can't see the advantage of Queue in this situation... Essentially, you use the Queue instead of the Condition. When you want to explicitly give up control in a thread, you get() on the Queue until you get an object (with the optional timeout). When the other thread is done processing, it puts an object on the Queue (optionally doing a get_nowait() at some point if it wants to make sure the Queue is cleaned up). The critical advantage of using Queue is that you don't have to do the acquire()/release() dance. It's not so much that there's an advantage to using Queue in this one specific case as the fact that you can use Queue for almost everything you'd use other kinds of locking mechanisms, so you can reduce your mental model for dealing with threading. -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
On Apr 18, 4:28 pm, a...@pythoncraft.com (Aahz) wrote: Essentially, you use the Queue instead of the Condition. When you want to explicitly give up control in a thread, you get() on the Queue until you get an object (with the optional timeout). When the other thread is done processing, it puts an object on the Queue (optionally doing a get_nowait() at some point if it wants to make sure the Queue is cleaned up). Yep but as I said I have nothing to pass around The critical advantage of using Queue is that you don't have to do the acquire()/release() dance. And neither do I have to using the with statement ;) It's not so much that there's an advantage to using Queue in this one specific case as the fact that you can use Queue for almost everything you'd use other kinds of locking mechanisms, so you can reduce your mental model for dealing with threading. That surely helps not making synchronization errors, but I like fully understanding the concept even if it means being bitten by it! But thanks for your tips, they will surely be helpful in some other situation... -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
In article f317e00e-042c-4894-83dc-bdd83fbbe...@y7g2000yqa.googlegroups.com, stephane.bisin...@gmail.com wrote: Well you know, the thing is that according to Pike Kernighan in The Practice of Programming, your first implementation of a program should be scrapped and rewritten from scratch, so your approach might not be that wrong after all. This observation was originally made in _The Mythical Man-Month_ by Fred Brooks, which ought to be required reading for all programmers. -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
On Apr 18, 4:44 pm, a...@pythoncraft.com (Aahz) wrote: This observation was originally made in _The Mythical Man-Month_ by Fred Brooks, which ought to be required reading for all programmers. I miss that one, yet :( Nice to know, though -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
In article 19475d1c-ee83-4466-ba55-b352ea760...@x5g2000yqk.googlegroups.com, stephane.bisin...@gmail.com wrote: On Apr 18, 4:28=A0pm, a...@pythoncraft.com (Aahz) wrote: Essentially, you use the Queue instead of the Condition. =A0When you want to explicitly give up control in a thread, you get() on the Queue until you get an object (with the optional timeout). =A0When the other thread i= s done processing, it puts an object on the Queue (optionally doing a get_nowait() at some point if it wants to make sure the Queue is cleaned up). Yep but as I said I have nothing to pass around You create it -- it's essentially a plain sentinel in this case. The critical advantage of using Queue is that you don't have to do the acquire()/release() dance. And neither do I have to using the with statement ;) Fair enough -- I was stuck on Python 2.3 in my last job and I still haven't caught up. -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] large db question about no joins
Daniel Fetchinson wrote: cut Thanks, this wikipedia entry was actually very useful as well as your other comments. Thanks again, Daniel Your welcome, I usually take quite a lot of effort into designing before I start coding. One tool I found very helpful was DIA, especially the UML section. Have a look at it you might find it useful. http://projects.gnome.org/dia/ -- MPH http://blog.dcuktec.com -- http://mail.python.org/mailman/listinfo/python-list
Re: need to start a new project , can python do all that ?
2009/4/17 Hyuga hyugaricd...@gmail.com: I'm not too assured... What are the actual requirements for this software? Is this intended for real world use in health care? I'm not too comfortable with a single individual with apparently limited experience in Python developing something like that. And limited experience in safety-related systems, if he thinks safety can be tested in, after the event. But of course it might be that the proposed system has gone through a proper safety analysis, and it /might/ have been determined that there are no safety or security risks with it, in which case there would be no reason for him not to cut his Python teeth (fangs?) on it. -- Tim Rowe -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
On Sat, 18 Apr 2009 13:39:23 +0200, BJörn Lindqvist wrote: I first started programming basic and i don't think it has hurt me much. I can somewhat sympathise with the op, neither python nor any other mainstream language can still do this: SCREEN 13 PSET 160,100,255 Maybe, maybe not. What on earth does it do? -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
On 18 Apr 2009 16:29:30 GMT Steven D'Aprano st...@remove-this-cybersource.com.au wrote: On Sat, 18 Apr 2009 13:39:23 +0200, BJörn Lindqvist wrote: SCREEN 13 PSET 160,100,255 Maybe, maybe not. What on earth does it do? It makes people scratch their heads and wonder what the hell it does. -- D'Arcy J.M. Cain da...@druid.net | Democracy is three wolves http://www.druid.net/darcy/| and a sheep voting on +1 416 425 1212 (DoD#0082)(eNTP) | what's for dinner. -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
2009/4/18 norseman norse...@hughes.net: ...only within the current procedure. That was one of the why Pascal didn't hang on as long as it might have. Really? I thought it was because of the lack of support for packaging, which was solved in different ways by Object Pascal/Delphi and by Modula 2, the latter of which in turn became Ada, which is still doing pretty well in mission-critical contexts. Another was it's COBAL structure in defining things. Just like today - the more typing the more errors, the longer to 'in service'. Got any evidence for that? There's a lot of typing in Ada (it shows its Pascal roots) but in all the studies I've seen Ada production code has consistently shown fewer errors than the more concise C/C++ family of languages. -- Tim Rowe -- http://mail.python.org/mailman/listinfo/python-list
Re: question about xrange performance
On Sat, 18 Apr 2009 13:05:34 +0200, mmanns wrote: On Fri, 17 Apr 2009 23:40:32 -0700 (PDT) bearophileh...@lycos.com wrote: Paul McGuire: xrange is not really intended for in testing, Let's add the semantic of a good and fast in to xrange (and to the range of Python3). It hurts no one, allows for a natural idiom (especially when you have a stride you don't want to re-invent the logic of skipping absent numbers), and it's readable. A fast in to xrange would be great. Why was it taken away? http://docs.python.org/whatsnew/2.2.html#other-changes-and-fixes Some features of the object returned by the xrange() function are now deprecated, and trigger warnings when they’re accessed; they’ll disappear in Python 2.3. xrange objects tried to pretend they were full sequence types by supporting slicing, sequence multiplication, and the in operator, but these features were rarely used and therefore buggy. The tolist() method and the start, stop, and step attributes are also being deprecated. At the C level, the fourth argument to the PyRange_New function, repeat, has also been deprecated. You may also want to read these: http://mail.python.org/pipermail/python-3000/2007-August/009061.html http://mail.python.org/pipermail/patches/2004-August/015501.html -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
In article mailman.4112.1240072722.11746.python-l...@python.org, Tim Rowe digi...@gmail.com wrote: Really? I thought it was because of the lack of support for packaging, which was solved in different ways by Object Pascal/Delphi and by Modula 2, the latter of which in turn became Ada, which is still doing pretty well in mission-critical contexts. blink I had never previously heard that Modula-2 significantly influenced Ada, and the Wikipedia entry says nothing about it. Do you have a cite? -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
Yep, I have heard a lot about test driven development. I am now programming a lot using DJango and I would like to use its test framework to try it. However, I have little experience with this (as most people I know). I also have no idea, how to apply this, when I write code heavily focused on user interface. I thought, that prototyping is cool, especially with python, where you can create something functional pretty quickly. But recently I was met with a situation, when after writing 1k lines of prototype and then writing main program 3k lines I noticed, that there is something really wrong with the design. It was then, that I started wondering: maybe I should first prepare some good design documents, I don't know some SAD or something. -- Filip Gruszczyński -- http://mail.python.org/mailman/listinfo/python-list
[no subject]
i have the following code : elif choice == 3: print all users list : print\n import active_directory for user in active_directory.search (objectCategory='Person', objectClass='User'): print user i want to write the output of the code ( LDAP://CN=bessy,OU=sales,DC=shay,DC=com LDAP://CN=ron,OU=legal,DC=shay,DC=com to a text \ csv file ... can any one help ?? -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
SCREEN 13 PSET 160,100,255 Maybe, maybe not. What on earth does it do? I believe this attempts to set screen-mode 13 (I'm surprised this isn't a hex constant, though that may be a (Q)Basic quirk), which for older VGA cards was 320x200 with 256-colors. It then looks like it sets a point at (160,100 = the middle of the screen) in color #255. Ah, back in the days where each application had to maintain the screen itself, and you had to use hacks to get square pixels (the 320x200 in this mode had a non-square aspect-ratio) in Mode-X. Can't say I miss it much beyond nostalgia. -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re:
On Sat, Apr 18, 2009 at 12:56 PM, karlos barlos karlosbar...@yahoo.com wrote: LDAP://CN=bessy,OU=sales,DC=shay,DC=com LDAP://CN=ron,OU=legal,DC=shay,DC=com to a text \ csv file ... can any one help ?? Have a look at this: http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files and this: http://docs.python.org/library/csv.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
On Apr 18, 5:54 pm, Filip Gruszczyński grusz...@gmail.com wrote: Yep, I have heard a lot about test driven development. I am now programming a lot using DJango and I would like to use its test framework to try it. However, I have little experience with this (as most people I know). I also have no idea, how to apply this, when I write code heavily focused on user interface. One of the most complete testing suites I know of is jUnit, even though you don't know Java, it may still be useful to you understand how the thing works. There is also a pyunit framework, but I fear that jUnit has a better overall documentation - anyway the concepts are similar. I thought, that prototyping is cool, especially with python, where you can create something functional pretty quickly. But recently I was met with a situation, when after writing 1k lines of prototype and then writing main program 3k lines I noticed, that there is something really wrong with the design. It was then, that I started wondering: maybe I should first prepare some good design documents, I don't know some SAD or something. My experience with design documents and all is that you end up not following them anyway because when you start to code you also start to realize you forgot something. Software Engineering would have you fall back to redesign to include the new stuff in, but I've hardly ever seen that happen. Of course you can try, because what works for me could not be working for you... The thing with software engineering is that nobody has found a good answer to these problems yet, no matter what they claim. Every approach has its advantages and its drawbacks, it is up to you to find your own way to deal with this kind of problems -- http://mail.python.org/mailman/listinfo/python-list
Re: Lambda alternative?
Duncan Booth duncan.bo...@invalid.invalid writes: import cPickle as p p.dumps([]) '(l.' p.dumps([].append) Traceback (most recent call last): File stdin, line 1, in module TypeError: expected string or Unicode object, NoneType found Not the best of examples: [].append is a built-in method rather than a bound method. Sorry about the confusion. By bound method I meant the callable obtained by binding a method (built-in or written in python) to a concrete instance, as opposed to an unbound method, such as list.append. The reprs are different for built-in methods and for python methods, but I consider that difference an artifact of the CPython implementation, not a distinction mandated by the language. -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
2009/4/18 Filip Gruszczyński grusz...@gmail.com: Yep, I have heard a lot about test driven development. I am now programming a lot using DJango and I would like to use its test framework to try it. However, I have little experience with this (as most people I know). I also have no idea, how to apply this, when I write code heavily focused on user interface. There are many testing frameworks to choose from with regards to interface, but at least starting with unit tests (which don't need to interact with the interface) will still gain you something, and help guide the design probably a little better than interface tests at that. My style of TDD is to alternate somewhat between the code and the tests. When that idea pops into my head about how to do something, I will either write a test OR write the code to make it work, depending on what my inspiration is. If the inspiration is API related, then the test gets written first, because what is in my head are really interface stuff and not implementation. On the other hand, if my inspiration is code/implementation related, I will write the code. Afterward, I will switch and write the other piece, which sort of backs up whatever my decision was (or doesn't). I don't follow this exactly, it's just my general coding style when I am using tests. Sometimes I don't use tests at all (they aren't quite as helpful in game programming as in other domains), and in those cases I generally try to refactor or clean up my code before a script gets too long, where too long means I am getting frustrated at not being able to find where to fix problems or add features fast enough. In practice, this usually means writing about 800-1000 lines of code in one script, and then exploding one script into several. I thought, that prototyping is cool, especially with python, where you can create something functional pretty quickly. But recently I was met with a situation, when after writing 1k lines of prototype and then writing main program 3k lines I noticed, that there is something really wrong with the design. It was then, that I started wondering: maybe I should first prepare some good design documents, I don't know some SAD or something. It's pretty hard to design very much up front, because when you get into the code things change. Maybe if you do some coding and then start designing as you go to keep yourself on the right track. -- http://mail.python.org/mailman/listinfo/python-list
Re: Too early implementation
Start to like blogging about your ideas, results and findings. Writing is a process of clarification of the mind. It doesn't matter much whether you design upfront, or mix coding and writing in an incremental process. If I could I'd just write specs, draft my ideas in Python in order to verify that I really know what I'm talking about and let others work out the details. Of course I'm not in the splendid position of a university professor or an intellectual capitalist. -- http://mail.python.org/mailman/listinfo/python-list
__getattribute__ for operators
While thinking about Steven D'Aprano's thread about automatically
generating arithmetic operations for a subclass, I stumbled upon
something confusing. Having defined the following class to do funky
addition,
class MyInt(int):
def __getattribute__(self, key):
if key == __add__:
print(In __getattribute__('__add__'))
return lambda other: MyInt(int.__add__(self, other+100))
else:
return object.__getattribute__(self, key)
def __getattr__(self, key):
if key == __add__:
print(In __getattr__('__add__'))
return lambda other: MyInt(int.__add__(self, other+100))
else:
return object.__getattr__(self, key)
I then do this:
a = MyInt(4)
a.__add__(2)
In __getattribute__('__add__')
106
a + 2
6
Why doesn't a + 2 look up the __add__ attribute and use my lambda?
If I manually define __add__(self, other) then a + 2 will of course
use that method.
Michael
--
http://mail.python.org/mailman/listinfo/python-list
Re: after_cancel?
W. eWatson wrote: I'm looking a program that I'm not real familiar with that uses an after_cancel method and after_id variable. Are they related to some particular widget and what is there function? Perhaps they are related to a Cancel button on a widget? http://www.pythonware.com/library/tkinter/introduction/x9507-alarm-handlers-and-other.htm -- http://mail.python.org/mailman/listinfo/python-list
Re:
--- On Sat, 4/18/09, Joe Riopel goo...@gmail.com wrote: From: Joe Riopel goo...@gmail.com Subject: Re: To: karlos barlos karlosbar...@yahoo.com Cc: python-list@python.org Date: Saturday, April 18, 2009, 12:01 PM On Sat, Apr 18, 2009 at 12:56 PM, karlos barlos karlosbar...@yahoo.com wrote: LDAP://CN=bessy,OU=sales,DC=shay,DC=com LDAP://CN=ron,OU=legal,DC=shay,DC=com to a text \ csv file ... can any one help ?? can some one give my an exmple on how to pipe the output into a csv. file ?? -- http://mail.python.org/mailman/listinfo/python-list
Re: Condition.wait(0.5) doesn't respect it's timeout
Gabriel Genellina gagsl-...@yahoo.com.ar (GG) wrote: GG If another thread has acquired the lock, cond.wait() doesn't return. Add GG these lines at the end of your test and see: GG sleep(2) GG print Main thread - cond.acquire() GG cond.acquire() GG sleep(2) GG print Main thread - cond.release() GG cond.release() GG sleep(2) GG sys.exit() GG The timeout is detected, but the wait method doesn't return, it's stuck at GG the last line (trying to restore a saved RLock state). GG I don't understand the logic behind that. That is the semantics of a Condition. The cond.wait() must be done in a critical section, i.e. when the thread has acquired the lock. The wait() temporarily releases the lock so that another thread can try to make the way free for the waiting thread and give a notify(). When the wait() continues it must first re-acquire the lock to make sure it has exclusive access to the critical section. If another thread still has the lock it has to wait for the lock being released. This is also the case when the wait continues because the timeout has expired. GG Please file a bug report at http://bugs.python.org/ It is not a bug. I see the Hello World temporarily suspended and then continuing. That's how it should be. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: pyqt4 qTableWidget add items help
On Apr 18, 3:46 am, Sebastian Wiesner basti.wies...@gmx.net wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 ookrin – Samstag, 18. April 2009 11:58 [...] I've been trying while(len(orders) i): ui.tb1_tblOrders.setCurrentCell(i,0,orders[i][1]) i+=1 which to me, says go add in the first column row with the first order, and it makes sense to me Read the documentation [1] to learn, what .setCurrentCell() actually does and what its arguments are! And please stop this wild guessing ... The method you're searching for is .setItem() [2], which adds a new QTableWidgetItem [3] to a QTableWidget. [1]http://doc.trolltech.com/4.5/qtablewidget.html#setCurrentCell [2]http://doc.trolltech.com/4.5/qtablewidget.html#setItem [3]http://doc.trolltech.com/4.5/qtablewidgetitem.html - -- Freedom is always the freedom of dissenters. (Rosa Luxemburg) -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.11 (GNU/Linux) iEYEARECAAYFAknpr4sACgkQGV4vxEMMOxdnawCfTXO55EffBJMQ7h91RGtMIpZ/ hcYAoLQ9yF5u/hBgNRvqxGRlIy5lPDgb =Q6ef -END PGP SIGNATURE- I forgot to include what I tried first. setCurrentItem was just the last thing I was on at the time. First I filled out a row in Designer to see how it loads the items. It loads like this: self.tb1_tblOrders.item(0, 0).setText(QtGui.QApplication.translate (MainWin, Date, None, QtGui.QApplication.UnicodeUTF8)) Ok following that example: ui.tb1_tblOrders.item(0,0).setText(QtGui.QApplication.translate (MainWindow,order[0][1], None,QtGui.QApplication.UnicodeUTF8)) AttributeError: 'NoneType' object has no attribute 'setText' So reading through the QTableWidget Doc I see the setItem setItem(int,int, QTableWidgetItem * item) QTableWidgetItem*item ??? The only example on the entire page: QTableWidgetItem *newItem = new QTableWidgetItem(tr(%1).arg( pow(row, column+1))); is that setup as c++ ? Ok, it's a class. twi = QTableWidgetItem() newItem = twi(order[i][0]) ui.tb1_tb1Orders.setItem(i,0,newItem) NameError: global name 'QTableWidgetItem' is not defined At the top of the page include QTableWidgetItem from PyQt4 import ?? QtGui? QtCore? Those are already loaded other options are pyqtconfig and uic and those don't sound correct... And that's what I did first. Then I started guessing in the next logical order, not wildly. editItem, setCurrentItem, setCurrentCell. Then I came here. So I guess I actually stuck at the QTableWidgetItem thing, I should have made that a little more clearer first post. Andrew -- http://mail.python.org/mailman/listinfo/python-list
Re: any complete and actual pysqlite example?
On Apr 18, 2009, at 8:59 AM, oyster wrote:
I mean not a code to do seperated functions, but a real project
I have read the doc of pysqlite, but since I know little about
database, I found it is still very hard for me to cook a real database
app from the scratch with the help of codelet in pysqlite doc. here is
the simplified details:
[TABLE 1]
bookName text
price num
author -- this is actually linked with the [TABLE 2], for one author
maybe write many books, I think it is better to do an external link
[/TABLE 1]
[TABLE 2]
authorName text
[/TABLE 2]
Then
[record for TABLE 1]
id bookName price authoridx
1 The Definitive Guide to SQLite 30 1
2 Core Python 40 2
3 Dive Into Python35 3
[/record for TABLE 1]
[record for TABLE 2]
id authorName
1 Michael Owens
2 Wesley J. Chun
3 Mark Pilgrim
[/record for TABLE 2]
what I need
1. of cause, create the TABLE, and add real data into it. I don't know
how to deal with the author item in [TABLE 1]
2. list the data. A question is, when I list the record in [TABLE 1],
can I get something like following?
The Definitive Guide to SQLite, 30.0, Michael Owens
I mean, the authorName is returned automatically, but not only the
authoridx
3. what if I del the 1st record in [TABLE 2] since a record in
[TABLE 1] use it?
4.I want to do some group, for example, group the record in [TABLE 1]
according to their price, so that
[30]
Book1Name
Book2Name
[40]
Book3Name
[50]
Book4Name
Book4Name
does sqlite support this? or I have to do this in python?
Hi Oyster,
It sounds like you're trying to learn several things at once. You
might find it easier to separate them so you can learn one thing at a
time.
Your questions are mostly about SQL and relational databases, not
Python or Python's interface to SQLite. Once you have a better
understanding of SQL and SQLite, the Python interface will make more
sense to you.
In order to learn SQLite, I suggest that you install it and play with
it on its own. There are probably precompiled binaries for your
platform:
http://www.sqlite.org/download.html
SQLite comes with a command line client similar to Python's
interactive shell, so you can enter database commands interactively
and see their output, like so:
$ sqlite3
SQLite version 3.4.0
Enter .help for instructions
sqlite CREATE TABLE books
... (
... id INTEGER NOT NULL PRIMARY KEY
AUTOINCREMENT,
... nameTEXT,
... price REAL,
... author_id INTEGER
... )
... ;
sqlite CREATE TABLE authors
... (
... id INTEGER NOT NULL PRIMARY KEY
AUTOINCREMENT,
... nameTEXT
... )
... ;
sqlite
sqlite INSERT INTO
... authors (name)
... VALUES
... ('Mrs. Premise');
sqlite
sqlite INSERT INTO
... authors (name)
... VALUES
... ('Mrs. Conclusion');
sqlite
sqlite SELECT
... *
... FROM
... authors;
id name
--
1 Mrs. Premise
2 Mrs. Conclus
sqlite
To answer your specific questions:
what I need
1. of cause, create the TABLE, and add real data into it. I don't know
how to deal with the author item in [TABLE 1]
There's sample create table statements above. The author_id in the
books table in my example is called a foreign key. You should read
more about them.
2. list the data. A question is, when I list the record in [TABLE 1],
can I get something like following?
The Definitive Guide to SQLite, 30.0, Michael Owens
I mean, the authorName is returned automatically, but not only the
authoridx
Yes, using something called a JOIN:
sqlite INSERT INTO
... books (name, price, author_id)
... VALUES
... ('The Big Book of Nonsense', 30.00, 1);
sqlite INSERT INTO
... books (name, price, author_id)
... VALUES
... ('Jean Paul Satre Goes to the Chemist', 25.00, 2);
sqlite
sqlite SELECT
... books.name, books.price, authors.name
... FROM
... books, authors
... WHERE
... books.author_id = authors.id;
name price name
--
The Big Book of Nonsense 30.0Mrs. Premise
Jean Paul Satre Goes to 25.0Mrs. Conclus
sqlite
3. what if I del the 1st record in [TABLE 2] since a record in
[TABLE 1] use it?
That's a problem! =) In a relational database you want to preserve
something called referential integrity. That means that if one table
refers to records in another table, you want to make sure that the
thing being referred to doesn't disappear. The SQL standard helps you
to defend against this problem with something called a foreign key
constraint. When you applied correctly, the database won't let you
delete a record if something is referring to it.
Re: Is there a programming language that is combination of Python andBasic?
On Apr 18, 2009, at 5:44 , Hendrik van Rooyen wrote: baykus b..@gmail.com wrote: I guess I did not articulate myself well enough. I was just looking for a toy to play around. I never suggested that Python+Basic would be better than Python and everyone should use it. Python is Python and Basic is Basic. I am not comparing them at all. I understand the merits of Python but that does not mean I can play with ideas? Apparently this is not allowed by the CS thought police. to untangle some spaghetti code. He did not mention if the spaghetti was actually doing it's job, bug free, which IMO is the only rational test for the quality of a piece of code, because it is the reason for its existence. The aesthetics are, like all aesthetics, a matter of opinion. Actually, I strongly disagree with this statement. In my experience, there has been very very few pieces of code that I've written that I hadn't wanted to *modify* at some point: extend it to a new set of circumstances, cover a different case, change the output, etc... The quality of a piece of code is not just if it works right now, but if you can reasonably extend it for the future. I toyed with Perl for a year or so, but couldn't give it my full attention. As a result, every few weeks when I wanted to modify what I wrote, I had to re- learn the code all over again because the syntax was so terse. The same is true for the typical use of a goto: you have to relearn the program, because the flow jumps around. It's not just about aesthetics, but about being able to work with a piece of code. bb -- Brian Blais bbl...@bryant.edu http://web.bryant.edu/~bblais -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python andBasic?
On Apr 18, 4:44 am, Hendrik van Rooyen m...@microcorp.co.za wrote: baykus b..@gmail.com wrote: I guess I did not articulate myself well enough. I was just looking for a toy to play around. I never suggested that Python+Basic would be better than Python and everyone should use it. Python is Python and Basic is Basic. I am not comparing them at all. I understand the merits of Python but that does not mean I can play with ideas? Apparently this is not allowed by the CS thought police. The reasoning is based on an Argument from Authority, namely the Dijkstra link. Now it looks to me when I read that article, that the jump is deprecated because it leads to code that is difficult to understand, which was based on the difficulty that Dijkstra had to construct a co-ordinate system for storing the state of a program at any given line of code. This was done without giving any reason as to why this should be important, or even desirable, except towards the end where he wanted to define instances in time when a count could conceivably be off by one, and he asserted without proof that having jumps in the code makes this more difficult. Even if this assertion were to be provably true, it does not really follow that jumps should be banned, but merely that one runs such a risk if one were to use them. Now to some minds, this difficulty may not be a difficulty at all: Processors and interrupt service routines are storing the state of multiple programmes at arbitrary points in the code, even as I type - and every one of those programmes include jumps. It is a non - issue. Mensanator had the same complaint based on difficulty earlier in this thread, when he described how he struggled to untangle some spaghetti code. He did not mention if the spaghetti was actually doing it's job, bug free, which IMO is the only rational test for the quality of a piece of code, because it is the reason for its existence. Oh, the bugs were there, alright. But they tended to be very subtle, so much so the original author must not have noticed them. For instance, a players AGILITY attribute affected the player's probability of hitting the monster he was attacking. This AGILITY attribute was altered by the quality of the player's armor, heavier plate armor being more adverse than light leather armor. In most situations, the adjustment is made once at the start of the game. Rarely is armor donned or removed during the course of the game. But it does happen in some games. I wrote one in which the player is captured and whatever armor he started the game with is taken away and part of his quest, in aggition to finding his way out of the dungeon, is to recover all the artifacts he entered the game with (which are hidden throughout to encourage wandering all over the layout). One of the symptoms of the spaghetti code's jumping around instead of doing subroutine returns was failure of the armor algorithm to properly adjust the AGILITY when armor is removed. The result was that AGILITY was only ever adjusted downwards, and never restored if it was taken off. If the player then subsequently donned it again, AGILITY would be further reduced. The same type of subtlty occured with monster COURAGE. Any monster (including the friendly ones who fought on your side) that didn't have a COURAGE rating of 100 was supposed to flee the room if a certain level of damage was taken. Again, because of goto screwups, such behaviour was rarely seen. Once corrected, it happened quite frequently, so much so that it affected the overall game itself. With the entire dynamic of the game beig very different, desingers estimates on how many monsters to place in a given scenario were all incorrect. The aesthetics are, like all aesthetics, a matter of opinion. Game design isn't just a matter of aesthetics. I do not agree with the reasoning that effectively says: If it is difficult to comprehend, it must be wrong A programmer once said to me Why should I run it, I know how it works, I wrote it. My reply: You only THINK you know how it works. _I_, on the other hand, ACTUALLY know how it works because I've run it. If this were to be a tenet, then using the pickle module should be forbidden too, as it is a complex piece of code that (to me at least) is not easily understood on a first read-through. So does that mean I must stop using pickles? All Strength to Arnaud for his goto code! I am looking forward to the gosub and return. :-) - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
I'm sort of mystified by the print hex to char conversion
I'm just really not seeing how something like x63 and/or x61 gets converted by 'print' to the corresponding chars in the following output... [cdal...@localhost oakland]$ python Python 2.4.3 (#1, Oct 1 2006, 18:00:19) [GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2 Type help, copyright, credits or license for more information. print '\x63had' chad print '\x63h\x61d' chad print \x63had chad print \x63h\x61d chad Does print just do this magically? -- http://mail.python.org/mailman/listinfo/python-list
Please help with problem creating class
Hi I have been working on a homework assignment that I am having a lot of trouble with. I am so frustrated because every time I think I am getting close to figuring it out there is another problem. If you could look at this and tell me what I am doing wrong I would very much appreciate it import string from datetime import date class Leaderapplicant: def __init__(self, line): #convert the lines of data into fields and removes \n line = line.rstrip(\n) appname, leadername, start, end = line.split(\t) self.appname = appname self.leadername = leadername , mm, dd = start.split(,) #splits the string into dates b = int() c = int(mm) d = int(dd) self.start = date(b,c,d) , mm, dd = end.split(,) b = int() c = int(mm) d = int(dd) self.end = date(b, c, d) def getAppname(self): return self.appname def getLeadername(self): return self.leadername def getStart(self): return self.start def getEnd(self): return self.end def getSomething(self): # infoStr is a tab separated line: name leadername startdate enddate return self.appname + \t + self.leadername + \t + self.start + \t + self.end #import Leader Applicant def get_files(): infile = raw_input(What file is the data in? ) outfile = raw_input(What file would you like the data to go in? ) return infile, outfile def main(): #recall get_files function files = get_files() #open files infile = open(files[0], 'r') outfile = open(files[1], 'w') reportstart = raw_input(Please enter the date (, mm, dd) the reporting period started: ) , mm, dd = string.split(reportstart, ,) = int() mm = int(mm) dd = int(dd) reportstartdate= date(, mm, dd) reportend = raw_input(Please enter the date (, mm, dd) the reporting period ended: ) , mm, dd = string.split(reportend, ,) = int() mm = int(mm) dd = int(dd) reportenddate = date(, mm, dd) for line in infile: a = Leaderapplicant(line) #from data file if a.getEnd() = reportstartdate and a.getEnd() = reportenddate: outfile.write(a.getAppname()) outfile.write (\n) #close files infile.close() outfile.close() #print The list has been written to, files[1] if __name__ == '__main__': main() I am using tab separated data in another file that looks like this... appname1 leadername12005, 02, 022006, 02, 02 appname2 leadername22006, 03, 212007, 06, 28 etc... The error message looks like this back (most recent call last): File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 97, in module main() File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 80, in main a = Leaderapplicant(line) #from data file File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 9, in __init__ appname, leadername, start, end = line.split(\t) ValueError: need more than 3 values to unpack Any help would be greatly appreciated. I have spent so much time on this that I am behind not only in this class but in other classes as well. -- http://mail.python.org/mailman/listinfo/python-list
Re: question about xrange performance
Steven D'Aprano st...@remove-this-cybersource.com.au writes: [...] Speaking about idiomacy, it is grammatically incorrect to start sentences in English with lower-case letters [...] [...] x.0 floats working with xrange is an accident, not a deliberate design decision, and has been deprecated in Python 2.6, which means it will probably be gone in a few years: -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
python alternatives to C structs??
Hey all,
I need to convert a C code to python please help me figure out how to
do
it.
Suppose the C program's like:
typedef struct _str
{
int a;
char *b;
int c;
}str;
int main()
{
str mbr;
fd=open(/dev/sda,O_RDONLY);
read(fd,mbr,sizeof(str));
}
Is there a way to code it in python.
Thanks
Sourya
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Re: Condition.wait(0.5) doesn't respect it's timeout
stephane.bisin...@gmail.com (SB) wrote: SB On Apr 18, 10:24 am, Piet van Oostrum p...@cs.uu.nl wrote: I haven't run it (too much hassle to setup) but I noticed one strange thing in your code: , | def groupUpdated(self, gView): | # Acquire the lock to do modifications | self._mod_lock.acquire() | | if not self._groups.has_key(gView.uid): | return ` In case the return is taken, the lock will not be released thereby blocking the rest. It could be that the timeout is taken, but before the wait can continue it has to acquire the lock again. SB That is absolutely correct, but I guess with an RLock there shouldn't SB be a deadlock... Anyway I'm fixing that! I suppose the groupUpdated() method is called from a different thread than the self._mod_lock.wait(timeout=1) because it contains a notify(). Otherwise your code would have been flawed. From the code you can see that this is the case as the thread with wait in it is created here (in aMSNContactListWidget.__init__) and it contains no calls to groupUpdated. Therefore the RLock thing isn't applicable. It was, however, applicable in the superfluous acquire in the loop, so it saved you there. Maybe you can put print statements at the beginning and end of each with block to see if there is an unreleased lock that blocks the wait. Some more remarks: 1. __repaint acquires the lock, but it is called from __thread_run which has already acquired it. Because the lock is recursive it doesn't harm but it is not necessary. 2. Importing in a thread is discouraged. I think it is cleaner to put the import sys in the top of the module. 3. I think I have found a bug in the Condition implementation, but I can't imagine you being hit by it. It would not be a reproducible one. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Please help with problem creating class
auzarski2...@gmail.com wrote: Hi I have been working on a homework assignment that I am having a lot of trouble with. I am so frustrated because every time I think I am getting close to figuring it out there is another problem. If you could look at this and tell me what I am doing wrong I would very much appreciate it import string from datetime import date class Leaderapplicant: def __init__(self, line): #convert the lines of data into fields and removes \n line = line.rstrip(\n) appname, leadername, start, end = line.split(\t) self.appname = appname self.leadername = leadername , mm, dd = start.split(,) #splits the string into dates b = int() c = int(mm) d = int(dd) self.start = date(b,c,d) , mm, dd = end.split(,) b = int() c = int(mm) d = int(dd) self.end = date(b, c, d) def getAppname(self): return self.appname def getLeadername(self): return self.leadername def getStart(self): return self.start def getEnd(self): return self.end def getSomething(self): # infoStr is a tab separated line: name leadername startdate enddate return self.appname + \t + self.leadername + \t + self.start + \t + self.end #import Leader Applicant def get_files(): infile = raw_input(What file is the data in? ) outfile = raw_input(What file would you like the data to go in? ) return infile, outfile def main(): #recall get_files function files = get_files() #open files infile = open(files[0], 'r') outfile = open(files[1], 'w') reportstart = raw_input(Please enter the date (, mm, dd) the reporting period started: ) , mm, dd = string.split(reportstart, ,) = int() mm = int(mm) dd = int(dd) reportstartdate= date(, mm, dd) reportend = raw_input(Please enter the date (, mm, dd) the reporting period ended: ) , mm, dd = string.split(reportend, ,) = int() mm = int(mm) dd = int(dd) reportenddate = date(, mm, dd) for line in infile: a = Leaderapplicant(line) #from data file if a.getEnd() = reportstartdate and a.getEnd() = reportenddate: outfile.write(a.getAppname()) outfile.write (\n) #close files infile.close() outfile.close() #print The list has been written to, files[1] if __name__ == '__main__': main() I am using tab separated data in another file that looks like this... appname1 leadername12005, 02, 022006, 02, 02 appname2 leadername22006, 03, 212007, 06, 28 etc... The error message looks like this back (most recent call last): File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 97, in module main() File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 80, in main a = Leaderapplicant(line) #from data file File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 9, in __init__ appname, leadername, start, end = line.split(\t) ValueError: need more than 3 values to unpack Any help would be greatly appreciated. I have spent so much time on this that I am behind not only in this class but in other classes as well. Print out the value of 'line' using repr(). Is it what you expected? -- http://mail.python.org/mailman/listinfo/python-list
Re: Please help with problem creating class
On 4/18/09, auzarski2...@gmail.com auzarski2...@gmail.com wrote: Hi I have been working on a homework assignment that I am having a lot of trouble with. I am so frustrated because every time I think I am getting close to figuring it out there is another problem. If you could look at this and tell me what I am doing wrong I would very much appreciate it import string from datetime import date class Leaderapplicant: def __init__(self, line): #convert the lines of data into fields and removes \n line = line.rstrip(\n) appname, leadername, start, end = line.split(\t) [...] I am using tab separated data in another file that looks like this... appname1 leadername12005, 02, 022006, 02, 02 appname2 leadername22006, 03, 212007, 06, 28 etc... The error message looks like this back (most recent call last): File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 97, in module main() File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 80, in main a = Leaderapplicant(line) #from data file File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 9, in __init__ appname, leadername, start, end = line.split(\t) ValueError: need more than 3 values to unpack Any help would be greatly appreciated. I have spent so much time on this that I am behind not only in this class but in other classes as well. Immediately before line 9 put the following line: print line.split(\t) Now run it again and see how many values are in the list that is printed. Your code expects that there will be exactly three. -- http://mail.python.org/mailman/listinfo/python-list
Re: Please help with problem creating class
Correction: On 4/18/09, member thudfoo thud...@opensuse.us wrote: On 4/18/09, auzarski2...@gmail.com auzarski2...@gmail.com wrote: Hi I have been working on a homework assignment that I am having a lot of trouble with. I am so frustrated because every time I think I am getting close to figuring it out there is another problem. If you could look at this and tell me what I am doing wrong I would very much appreciate it import string from datetime import date class Leaderapplicant: def __init__(self, line): #convert the lines of data into fields and removes \n line = line.rstrip(\n) appname, leadername, start, end = line.split(\t) [...] I am using tab separated data in another file that looks like this... appname1 leadername12005, 02, 022006, 02, 02 appname2 leadername22006, 03, 212007, 06, 28 etc... The error message looks like this back (most recent call last): File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 97, in module main() File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 80, in main a = Leaderapplicant(line) #from data file File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 9, in __init__ appname, leadername, start, end = line.split(\t) ValueError: need more than 3 values to unpack Any help would be greatly appreciated. I have spent so much time on this that I am behind not only in this class but in other classes as well. Immediately before line 9 put the following line: print line.split(\t) Now run it again and see how many values are in the list that is printed. Your code expects that there will be exactly four. -- http://mail.python.org/mailman/listinfo/python-list
Re: I'm sort of mystified by the print hex to char conversion
On Sat, 18 Apr 2009 11:45:09 -0700 (PDT), grocery_stocker wrote: I'm just really not seeing how something like x63 and/or x61 gets converted by 'print' to the corresponding chars in the following output... ... print \x63h\x61d chad Does print just do this magically? Not only print does that: a='\x63h\x61d' a 'chad' print a chad import sys sys.stdout.write(a) chad eval(a) Traceback (most recent call last): File stdin, line 1, in module File string, line 1, in module NameError: name 'chad' is not defined The policy is described here: http://www.python.org/doc/2.4.4/ref/strings.html Unlike Standard C, all unrecognized escape sequences are left in the string unchanged, i.e., the backslash is left in the string. (This behavior is useful when debugging: if an escape sequence is mistyped, the resulting output is more easily recognized as broken.) So, as long as the escape sequence is recognized it is changed accordingly. -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
Re: python alternatives to C structs??
On Sat, 18 Apr 2009 12:25:29 -0700 (PDT), KoolD wrote: Hi, I need to convert a C code to python please help me figure out how to do it. Suppose the C program's like: ... Is there a way to code it in python. You need struct module: http://docs.python.org/library/struct.html http://www.doughellmann.com/PyMOTW/struct/index.html http://code.activestate.com/recipes/498149/ HTH, -- Regards, Wojtek Walczak, http://tosh.pl/gminick/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Please help with problem creating class
auzarski2...@gmail.com wrote: I am using tab separated data in another file that looks like this... appname1 leadername12005, 02, 022006, 02, 02 appname2 leadername22006, 03, 212007, 06, 28 etc... The error message looks like this back (most recent call last): File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 97, in module main() File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 80, in main a = Leaderapplicant(line) #from data file File /home/amy/Documents/LIS452/assignment 3/testworks.py, line 9, in __init__ appname, leadername, start, end = line.split(\t) ValueError: need more than 3 values to unpack You assign the result of line.split() to four variables. So split needs at least four fields (that's more than three) in line to process. Examine your input data (appname1 leadername1 2005...), if it _really_ contains alt least three tab characters to separate the data fields. Maybe you created the input file by means of the same editor you use for coding your python code, so the probability is high, that the editor produces multiple space characters when you press the tab key. You could load the input file into vi or vim and give vi/vim the command :set list In list mode, tabs are rendered as '^I' (without the quotes). Or you use a hex editor or something like od to inspect the input file. Best regards, Günther -- http://mail.python.org/mailman/listinfo/python-list
Re: Overriding methods per-object
Pavel Panchekha pavpanche...@gmail.com (PP) wrote:
The docs don't say you can do that:
PP Thanks, hadn't noticed that.
Should you be able to?
PP I'd say so. In my case, I need a class that can encapsulate any
PP object, add a few methods to it, and spit something back that works
PP just like the object, but also has those extra methods. I can't just
PP add the methods, because it has to work on e.g. lists. So I'll have to
PP end up defining all the possible methods on that class (and that's
PP still not best because I can't use hasattr to test if, for example,
PP addition is allowed on that object).
PP On the other hand, I see how this severely restricts the possibly
PP optimizations that can be made in the interpreter.
But you can give each object its own class and then put the special
methods in that class:
def create_special_object(bases, *args):
... if not isinstance(bases, tuple):
... bases = bases,
... cls = type(SpecialClass, bases, {})
... return cls(*args)
...
a = create_special_object(list, [1,2,3])
a
[1, 2, 3]
a.__class__
class '__main__.SpecialClass'
a.__class__.__nonzero__ = lambda self: False
bool(a)
False
a.__nonzero__()
False
a.append(4)
a
[1, 2, 3, 4]
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Piet van Oostrum p...@cs.uu.nl
URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
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Any adv. in importing a module and some objects in the same module, into the same file?
http://docs.python.org/library/logging.html While going thr' the above link i came across import statements import logging import logging.handlers What is the use of second import as the first import will be enough(AFAIK) to access anything intended by the second import? Is there any kind of advantage? -- Thanks Regards visco -- http://mail.python.org/mailman/listinfo/python-list
for blackberry?
Is there any good way of getting python to run on a blackberry 8830 world edition? -- -- http://mail.python.org/mailman/listinfo/python-list
Re: How to create an unclosed dialog in wxPython?
Don't press alt+f4? ?? liangguan...@163.com wrote in message news:719e6773-bad0-46ff-9842-a7ade2ced...@f41g2000pra.googlegroups.com... In wxPython, after I create a wx.Frame, I want to create a modeless and unclosed dialog. Here is my step: app = wx.PySimpleApp() f = wx.Frame(None, -1, Test) d = wx.Dialog(f, -1, Test Dialog, style = wx.CAPTION) f.Show() d.Show() app.MainLoop() As you see, I create a dialog with wx.CAPTION style. And than, there is no close button in this dialog. It seems unclosed dialog, but in fact, if you enter Alt+F4 in this dialog, it will close. How could I do? -- http://mail.python.org/mailman/listinfo/python-list
Re: polar plots, clockwise, north
Thanks, I had tried this earlier but by rotating the data in this fashion, it has problems connecting the endpoints between 0 and 360 and tries to go counter clockwise around. I am then left with an extra circle in all my plots where it attempts to connect the points between 360 and 0 (now 100 and 0). -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing a parse tree
Dear John Machin So sorry about the typo. It should be: the program should *see* that the designated *words* are... a long way has two parentheses to the left -- (VP (DT -- before it hits a separate group -- VBD came). If there are three parenthesis, for instance (NP, this will means that what follows a long way is a modifier of a long way, as illustrated below: (VP (VBD came) (NP (NP (DT a) (JJ long) (NN way)) (PP (IN in) So I am trying to capture the grammatical relations following the designated words. -- http://mail.python.org/mailman/listinfo/python-list
How to create an unclosed dialog in wxPython?
In wxPython, after I create a wx.Frame, I want to create a modeless and unclosed dialog. Here is my step: app = wx.PySimpleApp() f = wx.Frame(None, -1, Test) d = wx.Dialog(f, -1, Test Dialog, style = wx.CAPTION) f.Show() d.Show() app.MainLoop() As you see, I create a dialog with wx.CAPTION style. And than, there is no close button in this dialog. It seems unclosed dialog, but in fact, if you enter Alt+F4 in this dialog, it will close. How could I do? -- http://mail.python.org/mailman/listinfo/python-list
Re: __getattribute__ for operators
Hmm... I meant to create a new thread, as does GMail when you edit the subject. Pardon my Google-Groups newbieness. - Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Please help with problem creating class
In article 3pmpb6-lq9@spamfence.net,
=?UTF-8?Q?G=C3=BCnther?= Dietrich guenther.dietr...@spamfence.net wrote:
You assign the result of line.split() to four variables. So split needs
at least four fields (that's more than three) in line to process.
s/at least/exactly/
w, x, y, z = '1\t2\t3\t4\t5'.split('\t')
Traceback (most recent call last):
File stdin, line 1, in ?
ValueError: too many values to unpack
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If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur. --Red Adair
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Re: Variables vs attributes
Steven D'Aprano st...@remove-this-cybersource.com.au (SD) wrote: SD On Fri, 17 Apr 2009 17:48:55 +0200, Diez B. Roggisch wrote: No, because you are creating *classvariables* when declaring things like this: SD ... OTOH, when assigning to an instance, this will create an *instance*-variable. Which is what SD If an integer variable is an integer, and a string variable is a string, SD and float variable is a float, and a list variable is a list (there's a SD pattern here), shouldn't a class variable be a class and an instance SD variable be an instance? If a wooden bench is made of wood, what is a garden bench made of? SD I had never noticed the usage of variable to mean attribute until a few SD months ago. What's going on? Why did people decide that confusing SD variables and attributes of variables was a good thing? What's next, SD describing dictionary keys as dictionary variables? If you google for 'instance variable python' you get quite a number of hits, not only recent ones. Albeit two orders of magnitude fewer than for 'attribute python'. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a programming language that is combination of Python and Basic?
2009/4/18 Aahz a...@pythoncraft.com: blink I had never previously heard that Modula-2 significantly influenced Ada, and the Wikipedia entry says nothing about it. Do you have a cite? Not in writing. I got it from a SPARK user group meeting many years ago. SPARK is, of course a subset of Ada with some mandatory structured comments, and is a successor to SPADE which was much the same thing for Pascal. When somebody asked one of the SPARK team -- I think it was Denton Clutterbuck -- why they'd gone from Pascal to Ada rather than Modula2, he observed If you look at the SPARK subset you'll see that it pretty much *is* Modula2. So whether Modula2 was a direct influence or not, it seems to have found its way in. -- Tim Rowe -- http://mail.python.org/mailman/listinfo/python-list
[no subject]
hello to all !! given the code : elif choice == 3: print all users list : print\n import active_directory for user in active_directory.search (objectCategory='Person', objectClass='User'): print user that lists all active directory personal ... how can i pipe this into a csv file ?? or a text file ? do need to first make it txt and then csv?? -- http://mail.python.org/mailman/listinfo/python-list
Re:
On Sat, Apr 18, 2009 at 4:23 PM, karlos barlos karlosbar...@yahoo.comwrote: hello to all !! given the code : elif choice == 3: print all users list : print\n import active_directory for user in active_directory.search (objectCategory='Person', objectClass='User'): print user that lists all active directory personal ... how can i pipe this into a csv file ?? or a text file ? do need to first make it txt and then csv?? http://www.lmgtfy.com/?q=python+csv Also, look at http://www.catb.org/~esr/faqs/smart-questions.html -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: __getattribute__ for operators
Michael wrote:
While thinking about Steven D'Aprano's thread about automatically
generating arithmetic operations for a subclass, I stumbled upon
something confusing. Having defined the following class to do funky
addition,
class MyInt(int):
def __getattribute__(self, key):
if key == __add__:
print(In __getattribute__('__add__'))
return lambda other: MyInt(int.__add__(self, other+100))
else:
return object.__getattribute__(self, key)
def __getattr__(self, key):
if key == __add__:
print(In __getattr__('__add__'))
return lambda other: MyInt(int.__add__(self, other+100))
else:
return object.__getattr__(self, key)
I then do this:
a = MyInt(4)
a.__add__(2)
In __getattribute__('__add__')
106
a + 2
6
Why doesn't a + 2 look up the __add__ attribute and use my lambda?
Answer 1: because it was not programmed that way ;-).
Answer 2: because __getattribute__/__getattr__ are for looking up
attributes of instances of the class, whereas special methods are
generally required to be attributes of the class. So *their* lookup
would use type(MyInt).__getxxx__. When that fails, the add code looks
for int.__radd__. (I *think* this your answer.)
If I manually define __add__(self, other) then a + 2 will of course
use that method.
because that is that type(MyInt).__getxxx__ will find.
tjr
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Re: __getattribute__ for operators
Michael gundl...@gmail.com (M) wrote:
M While thinking about Steven D'Aprano's thread about automatically
M generating arithmetic operations for a subclass, I stumbled upon
M something confusing. Having defined the following class to do funky
M addition,
M class MyInt(int):
M def __getattribute__(self, key):
M if key == __add__:
M print(In __getattribute__('__add__'))
M return lambda other: MyInt(int.__add__(self, other+100))
M else:
M return object.__getattribute__(self, key)
M def __getattr__(self, key):
M if key == __add__:
M print(In __getattr__('__add__'))
M return lambda other: MyInt(int.__add__(self, other+100))
M else:
M return object.__getattr__(self, key)
M I then do this:
a = MyInt(4)
a.__add__(2)
M In __getattribute__('__add__')
M 106
a + 2
M 6
M Why doesn't a + 2 look up the __add__ attribute and use my lambda?
M If I manually define __add__(self, other) then a + 2 will of course
M use that method.
This has just been discussed in the thread Overriding methods
per-object. In short: In newstyle classes these methods when invoked
implicitely, e.g by a+2, are only looked up in the class, and bypass
__getattribute__.
See
http://docs.python.org/reference/datamodel.html#special-method-lookup-for-new-style-classes
--
Piet van Oostrum p...@cs.uu.nl
URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
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Re: I'm sort of mystified by the print hex to char conversion
On Sat, 18 Apr 2009 11:45:09 -0700 (PDT), grocery_stocker wrote: I'm just really not seeing how something like x63 and/or x61 gets converted by 'print' to the corresponding chars in the following output... [cdal...@localhost oakland]$ python Python 2.4.3 (#1, Oct 1 2006, 18:00:19) [GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2 Type help, copyright, credits or license for more information. print '\x63had' chad print '\x63h\x61d' chad print \x63had chad print \x63h\x61d chad Does print just do this magically? I'm not sure what magic you see in there, but does the following help? a = \x63had len(a) 4 b = \x63h\x61d len(b) 4 Personally, when I'm puzzled by something involving a string with backslashes, I use len to help figure out what's really in the string and what's inserted on the way to my screen. -- To email me, substitute nowhere-spamcop, invalid-net. -- http://mail.python.org/mailman/listinfo/python-list
not homework... something i find an interesting problem
although it's not homework (how can i prove that...?) i am still happy with just hints +++ we want to express integers as sums of squares. (repeated squares are allowed) most numbers have one minimal representation e.g. 24=16+4+4, some have two or more e.g. 125 = 121+4 = 100+25 so far I have created a simple recursive function that expresses a given number as a sum of squares in the obvious and naive way. it returns a nested tuple , which is then flattened for simplicity...then to cover the possibility that there might be one other minimal representation i call another similar function which will find one other representation, not necessarily shorter or of equal length, finally these are sorted and the results displayed, with the minimal result or the 2 equal-length minimal results. as the numbers get bigger (i believe) there will be some which have 3 or more minimal representations which this code will miss. what I want to do is come up with a recursion that will find all possible minimal representations in one function (if possible ) in an optimally elegant and scalable way. There's no application in mind, i just love playing with math. code so far below: # express numbers as sum of squares a=[x**2 for x in range(50,0,-1)] # finds obvious candidate def squ(z): if z==0: return 0 for x in a: if z=x: return x,squ(z-x) # finds another candidate with largest square as next square down from above function def squ2(z): if z==0: return 0 for x in a: if z=x: return a[a.index(x)+1],squ(z-a[a.index(x)+1]) def flatten(lst): for elem in lst: if type(elem) in (tuple, list): for i in flatten(elem): yield i else: yield elem q=[] r=[] for aa in range(100): r.append([]) for xx in range(10,100): q=[] for ss in flatten(squ(xx)): if ss!=0: q.append(ss) r[xx].append(q) for xx in range(10,100): q=[] for ss in flatten(squ2(xx)): if ss!=0: q.append(ss) r[xx].append(q) for eee in r: if eee: if len(eee[0])==len(eee[1]): print r.index(eee),eee[0],eee[1] else: print r.index(eee),eee[0] -- http://mail.python.org/mailman/listinfo/python-list
Re: Any adv. in importing a module and some objects in the same module, into the same file?
Visco Shaun visc...@gmail.com (VS) wrote: VS http://docs.python.org/library/logging.html VS While going thr' the above link i came across import statements VS import logging VS import logging.handlers VS What is the use of second import as the first import will be VS enough(AFAIK) to access anything intended by the second import? VS Is there any kind of advantage? Have you tried? import logging logging.handlers Traceback (most recent call last): File stdin, line 1, in module AttributeError: 'module' object has no attribute 'handlers' import logging.handlers logging.handlers module 'logging.handlers' from '/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/logging/handlers.pyc' 'logging' is a package. The 'logging' module does not contain a definition of 'handlers' but there is a module 'handlers' in the 'logging' directory. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Overriding methods per-object
On Apr 18, 4:01 pm, Piet van Oostrum p...@cs.uu.nl wrote:
But you can give each object its own class and then put the special
methods in that class:
def create_special_object(bases, *args):
... if not isinstance(bases, tuple):
... bases = bases,
... cls = type(SpecialClass, bases, {})
... return cls(*args)
... a = create_special_object(list, [1,2,3])
a
[1, 2, 3]
a.__class__
class '__main__.SpecialClass'
a.__class__.__nonzero__ = lambda self: False
bool(a)
False
a.__nonzero__()
False
a.append(4)
a
[1, 2, 3, 4]
--
Piet van Oostrum p...@cs.uu.nl
URL:http://pietvanoostrum.com[PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
I think this is the solution I like best.
FYI this works as you expect if GeneralTypeOfObject is an old-style
class (i.e. does not inherit from object). If this feature is so more
important than all those that come with new-style classes, you have
control over the involved classes and don't care about Python 3.x
(where old-style classes are gone), you may choose to downgrade
GeneralTypeOfObject to old-style.
It is important, but new-style classes are important too. And I care
quite a bit about Python 3.x, thus the fact that I prefer the above
solution.
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