Re: Fibonacci series recursion error
On Sat, Apr 30, 2011 at 4:32 PM, Peter Otten <__pete...@web.de> wrote: >> ... because each recursion level 'return' calls fib() twice, and each >> of those calls fib() twice, and you get the point... > > I don't understand what you are trying to say -- but it's wrong ;) Fortunately, most Python interpreters will not implement double-tail-recursion as forking. Chris Angelico -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
harrismh777 wrote: > Ian Kelly wrote: >> since the fact is that if >> the function were properly coded, the call stack for fib(20) would >> never be more than 20 entries deep at any one time. >> > > Not so much... and much more ! > > > ... because each recursion level 'return' calls fib() twice, and each > of those calls fib() twice, and you get the point... I don't understand what you are trying to say -- but it's wrong ;) -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
harrismh777 wrote: > def fib(i=1): > a=1;n=1;l=[] > for j in range(0,i): > l.append(a) > p=a;a=n;n=p+a Hm, did you run out of newlines? > return l > > list=fib(7) > > > > ... and the above, is how I would actually code it > > > > Nah, that can't be it ;) For the record, the one true way to implement the Fibonacci series in Python is >>> def fib(): ... a = b = 1 ... while True: ... yield a ... a, b = b, a+b # look ma, no temporary variable ... >>> from itertools import islice >>> list(islice(fib(), 20)) [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765] -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
harrismh777 writes: > lalit wrote: >> The above function return the >> return (fib(n-1)+fib(n-2)) >> >> RuntimeError: maximum recursion depth exceeded in comparison >> [36355 refs] > > There is much debate about this generally, but general wisdom is that > recursion is to be avoided when possible. Another way to say this is, > "Only use recursion when there is no other obvious way to handle the > problem". > Recursion is very tempting to young artists because its a ~cool trick, > and because sometimes it requires very little coding (although huge > amounts of memory!), Writing recurive code is acceptable and is a nice clear way of expressing things when you have naturally recursive data structures, and can lead to perfectly good compiled code. The problem in CPython is the lack of tail optimization, so it's not a good idea for python . Some language standards guarantee tail optimization... -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
On Fri, 29 Apr 2011 23:45:30 -0500, harrismh777 wrote: : There is much debate about this generally, but general wisdom is that : recursion is to be avoided when possible. That is context dependent at best. You have given reasons to avoid recursion in /executable code/, but that's a compiler issue. You have only given reason /for/ recursion in source code. It generally gives little and very reaadble code. In almost every non-trivial software project, the programmers will be more overworked than the computer, and therefore they are the once to consider when optimising. : Recursion is very tempting to young artists because its a ~cool trick, : and because sometimes it requires very little coding (although huge : amounts of memory!), or as in your case, recursion depth errors. Waste of memory happens only with some types of recursion, and even then it is usually negligible. The recursion depth issue is the result of a flawed base case, and nothing to do with a weakness of recursion. : Anyway, the better way to build a Fibonacci sequence generator is the : following... I have expanded things a bit so that someone not knowing : what the sequence is can see what is happening... you will notice simple : 'for' iterations, and no recursion: And surprisingly difficult to read for such a well-known operation as Fibonacci numbers. If you want to promote iteration, you had better at least try to make it legible. Your code is obviously more efficient in being O(n) whereas OP had (I think) O(2^n), but that's not a property of iteration. You can make a recursive implementation which is O(n). Any undergraduate textbook teaching recursion in any depth is likely to give it as an example; see e.g. Simon Thompson's Haskell book. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
Ian Kelly wrote: since the fact is that if the function were properly coded, the call stack for fib(20) would never be more than 20 entries deep at any one time. Not so much... and much more ! ... because each recursion level 'return' calls fib() twice, and each of those calls fib() twice, and you get the point... (not to mention, its not properly coded) -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
def fib(i=1): a=1;n=1;l=[] for j in range(0,i): l.append(a) p=a;a=n;n=p+a return l list=fib(7) ... and the above, is how I would actually code it kind regards, m harris -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
On Fri, Apr 29, 2011 at 9:57 PM, Jason Friedman wrote: > The first call to fib() recursively calls fib() twice. Each of those > will call fib() twice. Each of those will call fib() twice. Pretty > soon, you've got a lot of calls. Which is hell for the running time, but doesn't answer the question of why the maximum recursion depth is exceeded, since the fact is that if the function were properly coded, the call stack for fib(20) would never be more than 20 entries deep at any one time. The actual problem, as Gary pointed out, is that the base case is incomplete. -- http://mail.python.org/mailman/listinfo/python-list
Installing programs that depend on, or are, python extensions.
I have noticed that installing python programs tends to be hell, particularly under windows, and installing python programs that rely on, or in large part are, python extensions written in C++ tends to be hell on wheels with large spiky knobs and scythes on the wheels. Is this because such install are inherently hard to do and hard to write, or is it because Install tends to be done last, and therefore not done at all? Can anyone suggest any examples of such a program with a clean windows install that shows how it was done? By windows install, I mean you run setup.exe, and get a program group, file types registered, and an entry in the add/remove programs list, I do not mean fourteen pages of direly incomplete notes which do not actually work for versions later than 1.01, and do not work for version 1.01 unless one has already installed the complete developer environment. -- http://mail.python.org/mailman/listinfo/python-list
Re: (beginner) logging config not working
Unknown Moss wrote:
> Hi
>
> This is a beginner question. Thanks for the hand.
>
> I've been asked to maintain some poorly constructed python code.
> Logging is weak. Getting it to work with python logging
> programmatically was easy.
>
> However, I'd like to refactor all the logging code into configuration
> since I see the need for other handlers in the future (syslog and
> possibly email).
>
> For now I just want to get console and log file working, but I'm
> having problems with the log file. I'm trying some test code. Here's
> my test script (logging_example.py):
>
> import logging
> import logging.config
>
> def main():
> logging.config.fileConfig("logging.conf")
> logging.debug("debug check")
The above is a shortcut for
root = logging.getLogger("")
root.debug("debug check")
i. e. you are logging to the root logger. According to your config file
messages sent to the root logger are only handled by the console handler:
> [logger_root]
> level=NOTSET
> handlers=console
You can either change that by adding the file handler to the list of
handlers for the root logger
handlers=console,file
in the config file or by directing your logging messages to "mylogger" with
mylogger = logging.getLogger("mylogger")
mylogger.debug("debug check")
Note that loggers are organized in a tree; messages sent to mylogger will be
propagated upwords to the root logger by default.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
===begin== def fib(i=1): l=[] p=0 a=1 n=p+a for j in range(1,i+1): l.append(a) p=a a=n n=p+a return l list=fib(7) ===end== ... the above, if you want to return the list, not print... -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
lalit wrote: The above function return the return (fib(n-1)+fib(n-2)) RuntimeError: maximum recursion depth exceeded in comparison [36355 refs] There is much debate about this generally, but general wisdom is that recursion is to be avoided when possible. Another way to say this is, "Only use recursion when there is no other obvious way to handle the problem". Recursion is very tempting to young artists because its a ~cool trick, and because sometimes it requires very little coding (although huge amounts of memory!), or as in your case, recursion depth errors. Anyway, the better way to build a Fibonacci sequence generator is the following... I have expanded things a bit so that someone not knowing what the sequence is can see what is happening... you will notice simple 'for' iterations, and no recursion: ===begin== def fib(i=1): l=[] p=0 a=1 n=p+a for j in range(1,i+1): l.append(a) p=a a=n n=p+a for j in l: print(j, end=' ') fib(7) ===end== kind regards, m harris -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
> import os > def fib(n): > if n == 1: > return(n) > else: > return (fib(n-1)+fib(n-2)) > > list=fib(20) > print(list) > > The above function return the > return (fib(n-1)+fib(n-2)) > > > RuntimeError: maximum recursion depth exceeded in comparison > [36355 refs] > > can any one help The first call to fib() recursively calls fib() twice. Each of those will call fib() twice. Each of those will call fib() twice. Pretty soon, you've got a lot of calls. Have a look at: http://en.literateprograms.org/Fibonacci_numbers_(Python). -- http://mail.python.org/mailman/listinfo/python-list
Re: Development tools and practices for Pythonistas
In article , CM wrote: > While we're on the topic, when should a lone developer bother to start > using a VCS? No need to use VCS at the very beginning of a project. You can easily wait until you've written 10 or 20 lines of code :-) > Should I bother to try a VCS? Absolutely. Even if you don't need it for a small one-person project, it's a good habit to get into. If you haven't used any, my recommendation would be hg. Partly because it's powerful, and partly because it's relatively easy to use. The other popular choice these days would be git. Hg and git are pretty similar, and between the two of them probably cover 90% of current usage. Unless you've got a specific reason to try something else (i.e. a project you're interested in uses something else), those seem like the only two reasonable choices. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fibonacci series recursion error
On 04/29/2011 08:22 PM, lalit wrote: import os def fib(n): if n == 1: return(n) else: return (fib(n-1)+fib(n-2)) list=fib(20) print(list) The above function return the return (fib(n-1)+fib(n-2)) RuntimeError: maximum recursion depth exceeded in comparison [36355 refs] can any one help You correctly test for n==1, but what about when n==2?When the recursion works its way down to fib(2), you call both fib(1) and fib(0), but the latter starts an infinite sequence of calls to fib(-1), fib(-2) and so on without end. Gary Herron -- http://mail.python.org/mailman/listinfo/python-list
Re: Development tools and practices for Pythonistas
Depends on the project, but I'd start with git the time I created the first file in my project. If you're in the habit of committing then you can easily rollback missteps. If you're in the habit of making branches you can experiment without breaking the currently-working code. -- http://mail.python.org/mailman/listinfo/python-list
Fibonacci series recursion error
import os def fib(n): if n == 1: return(n) else: return (fib(n-1)+fib(n-2)) list=fib(20) print(list) The above function return the return (fib(n-1)+fib(n-2)) RuntimeError: maximum recursion depth exceeded in comparison [36355 refs] can any one help -- http://mail.python.org/mailman/listinfo/python-list
Re: Development tools and practices for Pythonistas
> A lone developer using such a VCS reaps the benefits of this by getting > good merging support. While we're on the topic, when should a lone developer bother to start using a VCS? At what point in the complexity of a project (say a hobby project, but a somewhat seriousish one, around ~5-9k LOC) is the added complexity of bringing a VCS into it worth it? I've been making changes to code and saving changes to the same files, but backing up on Dropbox, which keeps 30 days of previous saves. I've rarely had to resort to undoing code by calling up a previous save. I test each new change as it is made to see if it breaks anything (not automatic testing, though), and I don't collaborate with anyone else as yet. Should I bother to try a VCS? -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
On Fri, Apr 29, 2011 at 5:54 PM, Carl Banks wrote: >> Really, *any* class that uses super().__init__ should take its >> arguments and pass them along in this manner. > > If you are programming defensively for any possible scenario, you might try > this (and you'd still fail). > > In the real world, certain classes might have more or less probability to be > used in a multiple inheritance situations, and programmer needs to weigh the > probability of that versus the loss of readability. For me, except when I'm > designing a class specifically to participate in MI (such as a mixin), > readability wins. Agreed. Actually, my preferred solution is to not use super at all. It's so rarely needed (i.e. diamond inheritance situations) that it's usually not worth it to jump through the hoops it creates, so I prefer to call the base class methods explicitly. For pure base-class + mixin design, you should not have any diamond inheritance situations, so super should not really be necessary. > If you merely mean DRY, then I'd say this doesn't necessarily add to it. The > derived class has a responsibility one way or another to get the mixin > whatever initializers it needs. I mean the difference in terms of maintenance between this: class Derived1(Mixin1, Base): def __init__(self, mixin_arg1, mixin_arg2, *args, **kwargs): self.mixin_arg1 = mixin_arg1 self.mixin_arg2 = mixin_arg2 super(Derived, self).__init__(*args, **kwargs) and simply doing this: class Derived2(Mixin2, Base): def __init__(self, *args, **kwargs): super(Derived, self).__init__(*args, **kwargs) In both cases we are passing the arguments in to the mixin. In the former case, if we later decide to add mixin_arg3, then we have to also add it to the Derived1.__init__ signature and then add a line to set the attribute. In the latter case, adding mixin_arg3 has no effect on the Derived2 initializer at all, because it passes through transparently in the kwargs. Cheers, Ian -- http://mail.python.org/mailman/listinfo/python-list
(beginner) logging config not working
Hi
This is a beginner question. Thanks for the hand.
I've been asked to maintain some poorly constructed python code.
Logging is weak. Getting it to work with python logging
programmatically was easy.
However, I'd like to refactor all the logging code into configuration
since I see the need for other handlers in the future (syslog and
possibly email).
For now I just want to get console and log file working, but I'm
having problems with the log file. I'm trying some test code. Here's
my test script (logging_example.py):
import logging
import logging.config
def main():
logging.config.fileConfig("logging.conf")
logging.debug("debug check")
logging.info("info check")
logging.warn("warn check")
logging.error("err check")
logging.critical("crit check")
if __name__ == "__main__":
main()
Here's my config (logging.conf):
[loggers]
keys=root,file
[handlers]
keys=console,file
[formatters]
keys=simple,detailed
[logger_root]
level=NOTSET
handlers=console
[logger_file]
level=DEBUG
handlers=file
qualname=mylogger
[formatter_simple]
class=logging.Formatter
format=%(asctime)s - %(name)s [%(levelname)s] - %(message)s
[formatter_detailed]
class=logging.Formatter
format=%(asctime)s - %(name)s [%(levelname)s] - %(message)s
[handler_console]
class=logging.StreamHandler
formatter=simple
args=(sys.stdout,)
[handler_file]
class=FileHandler
level=DEBUG
formatter=detailed
args=('logging_example.log', 'w')
Output:
$ python logging_example.py
2011-04-29 17:07:01,923 - root [DEBUG] - debug check
2011-04-29 17:07:01,986 - root [INFO] - info check
2011-04-29 17:07:01,986 - root [WARNING] - warn check
2011-04-29 17:07:01,986 - root [ERROR] - err check
2011-04-29 17:07:02,000 - root [CRITICAL] - crit check
The logging_example.log is created, but no entries are written to it.
Based on this configuration I'd expect all the logging entries to be
written to the file as well.
Any ideas where I'm going awry?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
On Friday, April 29, 2011 2:44:56 PM UTC-7, Ian wrote: > On Fri, Apr 29, 2011 at 3:09 PM, Carl Banks > wrote: > > Here is my advice on mixins: > > > > Mixins should almost always be listed first in the bases. (The only > > exception is to work around a technicality. Otherwise mixins go first.) > > > > If a mixin defines __init__, it should always accept self, *args and > > **kwargs (and no other arguments), and pass those on to super().__init__. > > Same deal with any other function that different sister classes might > > define in varied ways (such as __call__). > > Really, *any* class that uses super().__init__ should take its > arguments and pass them along in this manner. If you are programming defensively for any possible scenario, you might try this (and you'd still fail). In the real world, certain classes might have more or less probability to be used in a multiple inheritance situations, and programmer needs to weigh the probability of that versus the loss of readability. For me, except when I'm designing a class specifically to participate in MI (such as a mixin), readability wins. [snip] > > A mixin should not accept arguments in __init__. Instead, it should burden > > the derived class to accept arguments on its behalf, and set attributes > > before calling super().__init__, which the mixin can access. > > Ugh. This breaks encapsulation, since if I ever need to add an > optional argument, I have to add handling for that argument to every > derived class that uses that mixin. The mixin should be able to > accept new optional arguments without the derived classes needing to > know about them. Well, encapsulation means nothing to me; if it did I'd be using Java. If you merely mean DRY, then I'd say this doesn't necessarily add to it. The derived class has a responsibility one way or another to get the mixin whatever initializers it needs. Whether it does that with __init__ args or through attributes it still has to do it. Since attributes are more versatile than arguments, and since it's messy to use arguments in MI situations, using attributes is the superior method. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Development tools and practices for Pythonistas
Hans Georg Schaathun writes: > Exactly, and with svn that can be a true nightmare when directories > are involved. The rumour is that git handles this much better. Any of the top-tier distributed VCS (Bazaar, Git, Mercurial) handle branching and merging very well. They have to, because branching and merging is much more frequent and casual in a distributed VCS. A lone developer using such a VCS reaps the benefits of this by getting good merging support. -- \ “If consumers even know there's a DRM, what it is, and how it | `\ works, we've already failed.” —Peter Lee, Disney corporation, | _o__) 2005 | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: cx_Freeze 4.2.3
I get this error too using Apple's system python. On Mar 31, 7:49 pm, James Mills wrote: > On Sun, Mar 20, 2011 at 9:52 AM, Anthony Tuininga > > wrote: > > Where do I get it? > > >http://cx-freeze.sourceforge.net > > Just as a matter of interest, I tried to install cx_Freeze with > pip/distribute (Python 2.7.1) > but it fails with: > > error: option --single-version-externally-managed not recognized > > cheers > James > > -- > -- James Mills > -- > -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
Ian Kelly wrote: On Thu, Apr 28, 2011 at 11:15 AM, Ethan Furman wrote: For anybody interested in composition instead of multiple inheritance, I have posted this recipe on ActiveState (for python 2.6/7, not 3.x): http://code.activestate.com/recipes/577658-composition-of-classes-instead-of-multiple-inherit/ Comments welcome! On line 14, is it intentional that attributes whose values happen to be false are not considered as conflicts? Nope, not intentional at all! I'll fix that... On line 31, this code: thing = getattr(thing, '__func__', None) or thing could be simplified to this: thing = getattr(thing, '__func__', thing) I'll fix that, too. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
On Fri, Apr 29, 2011 at 3:09 PM, Carl Banks wrote: > Here is my advice on mixins: > > Mixins should almost always be listed first in the bases. (The only > exception is to work around a technicality. Otherwise mixins go first.) > > If a mixin defines __init__, it should always accept self, *args and **kwargs > (and no other arguments), and pass those on to super().__init__. Same deal > with any other function that different sister classes might define in varied > ways (such as __call__). Really, *any* class that uses super().__init__ should take its arguments and pass them along in this manner. This applies to your base classes as well as your mixins. It's okay to take keyword arguments as well, but you have to be careful to pass them on exactly as you received them. Reason being that you can't pragmatically predict which __init__ method will be invoked next by the super call, which means that you can't predict which arguments will be needed for that call, so you just have to pass all of them along. > A mixin should not accept arguments in __init__. Instead, it should burden > the derived class to accept arguments on its behalf, and set attributes > before calling super().__init__, which the mixin can access. Ugh. This breaks encapsulation, since if I ever need to add an optional argument, I have to add handling for that argument to every derived class that uses that mixin. The mixin should be able to accept new optional arguments without the derived classes needing to know about them. > If you insist on a mixin that accepts arguments in __init__, then it should > should pop them off kwargs. Avoid using positional arguments, and never use > named arguments. Always go through args and kwargs. Theoretically this would break if you had two mixins accepting the same argument, but I can't think of an actual case where that might happen. Cheers, Ian -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
Carl Banks wrote: Here is my advice on mixins: [snip] Cool. Thanks! ~Ethan -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
On Thursday, April 28, 2011 6:43:35 PM UTC-7, Ethan Furman wrote: > Carl Banks wrote: > > The sorts of class that this decorator will work for are probably not > > the ones that are going to have problems cooperating in the first place. > > So you might as well just use inheritance; that way people trying to read > > the code will have a common, well-known Python construct rather than a > > custom decorator to understand. > > From thread 'python and super' on Python-Dev: > Ricardo Kirkner wrote: > > I'll give you the example I came upon: > > > > I have a TestCase class, which inherits from both Django's TestCase > > and from some custom TestCases that act as mixin classes. So I have > > something like > > > > class MyTestCase(TestCase, Mixin1, Mixin2): > >... > > > > now django's TestCase class inherits from unittest2.TestCase, which we > > found was not calling super. > > This is the type of situation the decorator was written for (although > it's too simplistic to handle that exact case, as Ricardo goes on to say > he has a setUp in each mixin that needs to be called -- it works fine > though if you are not adding duplicate names). The problem is that he was doing mixins wrong. Way wrong. Here is my advice on mixins: Mixins should almost always be listed first in the bases. (The only exception is to work around a technicality. Otherwise mixins go first.) If a mixin defines __init__, it should always accept self, *args and **kwargs (and no other arguments), and pass those on to super().__init__. Same deal with any other function that different sister classes might define in varied ways (such as __call__). A mixin should not accept arguments in __init__. Instead, it should burden the derived class to accept arguments on its behalf, and set attributes before calling super().__init__, which the mixin can access. If you insist on a mixin that accepts arguments in __init__, then it should should pop them off kwargs. Avoid using positional arguments, and never use named arguments. Always go through args and kwargs. If mixins follow these rules, they'll be reasonably safe to use on a variety of classes. (Maybe even safe enough to use in Django classes.) Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Deditor
On 29 apr, 20:25, jmfauth wrote: > On 28 avr, 22:16, Kruptein wrote: > > > > > > > On 28 apr, 07:46, jmfauth wrote: > > > > On 27 avr, 19:22, Alec Taylor wrote: > > > > > Thanks, any plans for a Windows version? > > > > - Download the deb > > > - Unpack it with a utility like 7zip > > > - Throw away the unnecessary stuff, (keep the "deditorpart") > > > - Depending on your libs, adatpt the "import" > > > - Launchdeditor.py > > > - Then ... > > > > [5 minutes] > > > > In fact, this kind of app can be simply packed in a zip file. > > > > jmf > > > It isn't that easy as you might have hoped ;) I'm using wxpython for > > rendering the GUI somehow some things that work in the linux version > > break in the windows version so I need to do some small > > modifications and as I'm a hardcore linux fan I ony use windows for > > gaming it usually takes a little longer for a windows release, I'm > > releasing a tarball now btw :D > > Sure, it is doable. I have done it (I only tweak the > import in such a way, that it does not import modules > not installed in my machine, like not importing paramiko). > > Your application is just a normal application which uses > a Python environment, independently from the platform. > > wxPython does not play something special. Exemple, the > wxPython demo can be installed in any dir, even on external > drive. > > PS I have no special interest indeditor, except I like > to see what is done with wxPython. > > jmf The problem had to do with the configuration panel which displayed wrong in windows but right in linux. I fixed it and it should now actually work on both :p (and the paramiko import error was because I had forgooten to do a try/ except block somewhere in my plugin management..) the windows source zip file is online, Alec can make an installer if he wants :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
James Mills wrote: On Fri, Apr 29, 2011 at 11:43 AM, Ethan Furman wrote: Hmmm. Okay -- any ideas for a better term? Something that describes taking different source classes and fusing them into a new whole, possibly using single-inheritance... Frankenstein, maybe? ;) I'd have to say that this is typical of MixIns Yes, but it's designed to be used when Mixins fail because of MI issues (see my reply to Carl for an example). Maybe Integrate? ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list
Re: windows 7 x64 shutdown
On Mon, Apr 25, 2011 at 16:15, rjmccorkle wrote: > does anyone know a solution to shutting down windows 7 x64 via python > script? the win32 obviously doesn't work... something similar? > > "the win32 obviously doesn't work" -- It does. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python wide-python-build unicode for Windows
On 4/29/2011 7:52 AM, sathe...@e-ndicus.com wrote: How could i increase the unicode range beyond 1 ? Use Python3, which, after renaming unichar to chr, changed it to always accept the full range of codepoints, even when that means returning a two-char string on narrow builds, like windows. >>> chr(0x10) '\U0010' >>> len(chr(0x10)) 2 If OpenERP does not have a 3.x version, encourage them to make one to take advantage of the unicode improvements. Tell them the use case, that you want to use the full range, even on windows. Or file a bug report requesting a workaround in the 2.x version. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Python wide-python-build unicode for Windows
> But how could i do this in Windows. It's not supported. Hopefully, it will be supported in Python 3.3, due to PEP 393. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Development tools and practices for Pythonistas
On Wed, 27 Apr 2011 14:24:30 +0200, Jean-Michel Pichavant wrote: : I was talking about merge *issue* i.e merge resulting in conflicts that : are not easy to solve. With a single user most of the merge will be : solved automatically by any decent VCS. Exactly, and with svn that can be a true nightmare when directories are involved. The rumour is that git handles this much better. I call it a rumour not because I doubt it (I don't), but because I have not seen for myself. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] VCS tools
On 2011-04-28, Ben Finney wrote: > Martin Schöön writes: > >> This has been a pretty informative thread so far. Please keep it coming. >> I am a hardware development guy and do very little software development. >> I have been vaguely aware of tools for version control but inspired by >> this thread I have started looking at Mercurial. > > After my passionate Bazaar evangelism? :-) > Before I think as I remember I was quick out of the blocks. > I seriously recommend anyone looking for a modern VCS to give Bazaar a > decent trial. It's the one I've found newcomers learn most easily, and > it's astoundingly flexible as one's needs with it grow. > I'll take look but so far I have found Mercurial pretty easy to get to grips with. But then I have only done fairly trivial stuff. /Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Deditor
On 28 avr, 22:16, Kruptein wrote: > On 28 apr, 07:46, jmfauth wrote: > > > > > On 27 avr, 19:22, Alec Taylor wrote: > > > > Thanks, any plans for a Windows version? > > > - Download the deb > > - Unpack it with a utility like 7zip > > - Throw away the unnecessary stuff, (keep the "deditor part") > > - Depending on your libs, adatpt the "import" > > - Launch deditor.py > > - Then ... > > > [5 minutes] > > > In fact, this kind of app can be simply packed in a zip file. > > > jmf > > It isn't that easy as you might have hoped ;) I'm using wxpython for > rendering the GUI somehow some things that work in the linux version > break in the windows version so I need to do some small > modifications and as I'm a hardcore linux fan I ony use windows for > gaming it usually takes a little longer for a windows release, I'm > releasing a tarball now btw :D Sure, it is doable. I have done it (I only tweak the import in such a way, that it does not import modules not installed in my machine, like not importing paramiko). Your application is just a normal application which uses a Python environment, independently from the platform. wxPython does not play something special. Exemple, the wxPython demo can be installed in any dir, even on external drive. PS I have no special interest in deditor, except I like to see what is done with wxPython. jmf -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] From svn to something else?
On 04/29/2011 12:01 PM, Hans Georg Schaathun wrote: wrote: : I'd say that one of the things SVN has going for it is that it's : the lingua-franca of VCSes, so just about everything (especially : the 3 big names mentioned in this thread: hg, bzr, git) can talk : to svn pretty uneventfully. As a matter of fact, last I checked, : Django is hosted in SVN, but most of the developers use DVCS : tools to check in/out from the main repository to their own local : hg/bzr/git repos, do their work locally (with the option to work : offline, branch/merge easily, etc), and then push changesets back : up when they have a patch they're happy with. I am not sure I get the implications right. Are you suggesting that I could keep my svn server, switch to a DVCS client, and reap the benefits? Yep...some are plugins while others are stock/native, but you can read your fill at Git: http://www.kernel.org/pub/software/scm/git/docs/git-svn.html Mercurial: http://mercurial.selenic.com/wiki/WorkingWithSubversion Bazaar: http://doc.bazaar.canonical.com/plugins/en/svn-plugin.html -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] Comparing VCS tools (was ""Development tools and practices for Pythonistas")
We were looking for some simple integrated SCM, issue tracker and wiki in our university for software design and software testing courses, and fossil seems to be perfect match, thanks for sharing. -- With best regards, Daniel Kluev -- http://mail.python.org/mailman/listinfo/python-list
Thank You Re: use of index (beginner's question)
An overdue Thank You to everyone who responded. I got well more than I
bargained for, including needed reinforcement (beyond the beginner's
guides) of how Python actually works and some good programming habits. I
am grateful.
I liked Steven D'Aprano comment:
Define "does not work".
What do you expect to happen, and what happens instead?
A good dose of humility. Getting a result that surprises me isn't the
same as the language not working!
In the end I followed Thomas Lahn's suggestion and used the structure
data = {
'pig': '62327',
'horse': '49123',
'moose': '79115'
}
print data.get('horse')
I am using the Python extension written for ArcGIS software.
The happy result is a set of 54 maps, each with three frames, which
display gridded tuna harvest data for 3 tuna species from 1950 through
2004 as well as total tonnages. And the beauty is, if I modify the basic
map template I need only execute the program again, go have coffee, and
come back to 54 new pdf files! The boss can say 'change the title font'
and it's no big deal.
Thanks again,
Rusty Scalf
On 4/27/2011 5:42 PM, Rusty Scalf wrote:
Greetings,
I am just now learning python and am trying to use the index function
with variables.
list1 = ['pig', 'horse', 'moose']
list2 = ['62327', '49123', '79115']
a = list2[list1.index('horse')]
print a
>49123
-works fine. But
list1 = ['pig', 'horse', 'moose']
list2 = ['62327', '49123', '79115']
n = 2
s2 = "list" + `n`
a = s2[list1.index('horse')]
print a
-does not work
I'd like to use the index function in a loop updating the file names
by adding a number to that name with each cycle. But can't get to
first base.
Thank you,
Rusty Scalf
--
http://mail.python.org/mailman/listinfo/python-list
Re: Deditor
I'll create an installer or two (an NSIS or InnoSetup .exe and an MSI) if you like, once you've released the windows version. On Fri, Apr 29, 2011 at 6:16 AM, Kruptein wrote: > On 28 apr, 07:46, jmfauth wrote: >> On 27 avr, 19:22, Alec Taylor wrote: >> >> > Thanks, any plans for a Windows version? >> >> - Download the deb >> - Unpack it with a utility like 7zip >> - Throw away the unnecessary stuff, (keep the "deditor part") >> - Depending on your libs, adatpt the "import" >> - Launch deditor.py >> - Then ... >> >> [5 minutes] >> >> In fact, this kind of app can be simply packed in a zip file. >> >> jmf > > It isn't that easy as you might have hoped ;) I'm using wxpython for > rendering the GUI somehow some things that work in the linux version > break in the windows version so I need to do some small > modifications and as I'm a hardcore linux fan I ony use windows for > gaming it usually takes a little longer for a windows release, I'm > releasing a tarball now btw :D > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] From svn to something else?
On Fri, 29 Apr 2011 06:50:52 -0500, Tim Chase wrote: : I'd say that one of the things SVN has going for it is that it's : the lingua-franca of VCSes, so just about everything (especially : the 3 big names mentioned in this thread: hg, bzr, git) can talk : to svn pretty uneventfully. As a matter of fact, last I checked, : Django is hosted in SVN, but most of the developers use DVCS : tools to check in/out from the main repository to their own local : hg/bzr/git repos, do their work locally (with the option to work : offline, branch/merge easily, etc), and then push changesets back : up when they have a patch they're happy with. I am not sure I get the implications right. Are you suggesting that I could keep my svn server, switch to a DVCS client, and reap the benefits? -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: Read-write lock for Python
On Fri, Apr 29, 2011 at 12:38 AM, Ryan Kelly wrote: > On Thu, 2011-04-28 at 07:02 -0700, Geoff Bache wrote: >> Hi all, >> >> I currently find myself needing a Python read-write lock. I note that >> there is none in the standard library, but googling "python read-write >> lock" quickly produced 6 different competing examples, including two >> languishing patch proposals for the standard library. >> >> I can always pick a random one and hope for the best, but I was hoping >> someone here might have a tip for one that has been used and debugged >> and is likely to work. > > I wrote and have used the "SHLock" class in threading2 which should do > what you need. Don't know about "likely to work" but if it doesn't, I'd > like to hear about it so I can fix it :-) That's good enough for me :) Thanks, I'll give it a try. /Geoff -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] Comparing VCS tools (was ""Development tools and practices for Pythonistas")
Fossil is another SCM to consider: http://www.fossil-scm.org/ It's written by the author of SQLite, D. Richard Hipp. It's not as well-known as some of the other DCVS's, but the Tcl/Tk language projects have moved their core development to it (http://core.tcl.tk). This is relevant to Python because Tkinter is part of the stlib. There aren't any huge sites like Github providing Fossil hosting, but here is one site: http://chiselapp.com/ --Kevin -- Kevin Walzer Code by Kevin http://www.codebykevin.com -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] From svn to something else?
On Fri, 29 Apr 2011 22:53:47 +1000 Ben Finney wrote: > Bazaar's support for Subversion repositories is great (it requires the > ‘bzr-svn’ plug-in, of course). Use the ‘svn-import’ subcommand to import > an entire Subversion repository to a Bazaar repository with all branches > and history intact. Anyone know how to go the other way? I recently converted all my projects over to svn from cvs and then took over another project that uses bzr. I would prefer everything to be in the same system. -- D'Arcy J.M. Cain | 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: [OT] From svn to something else?
Hans Georg Schaathun writes: > How easy and reliable is it to import my svn version history into > one of the three big DVCS-s mentioned here? Bazaar's support for Subversion repositories is great (it requires the ‘bzr-svn’ plug-in, of course). Use the ‘svn-import’ subcommand to import an entire Subversion repository to a Bazaar repository with all branches and history intact. -- \“Your [government] representative owes you, not his industry | `\ only, but his judgment; and he betrays, instead of serving you, | _o__)if he sacrifices it to your opinion.” —Edmund Burke, 1774 | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Active Directory user creation with python-ldap
Nello wrote: > I need to create an Active Directory user using python-ldap library. So, I > authenticate with an admin account and I use "add_s" to create the user. This is possible. Which version of AD are you working with. > Anyway, by default users are disabled on creation, That's the correct way of doing this. > and I can not set > userAccountControl to swith off the flag ACCOUNTDISABLE, i.e. setting > userAccountControl with 512 (NORMAL_ACCOUNT) value. This should be possible. Make sure you really bind as the admin and you have sufficient access rights. Check your code. I'd suggest to set trace_level when calling ldap.initialize() to observe what gets passed to python-ldap in which order. http://www.python-ldap.org/doc/html/ldap.html#ldap.initialize > Same thing if - as someone suggests - I create the user without a > password and try to set userAccountCreation later. Passwords are different anyway since you have to set the unicodePwd attribute. I never tried to do this with a single write operation though. You can try my web2ldap which does all this also with MS AD. It has a special plugin class for attribute userAccountControl which lets you set values bit-wise when modifying an user entry. And setting password automagically switches to setting unicodePwd when working with MS AD. Ciao, Michael. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to build an application in Django which will handle Multiple servers accross network
On Fri, 2011-04-29 at 13:24 +0200, Paul Kölle wrote: > Am 29.04.2011 12:01, schrieb Adam Tauno Williams: > >> 3. The web based application will be used internally in the network to > >> moniter servers in that network only. > > You mean like OpenNMS or ZenOSS? > >> 4. Web based application will be a real time application with a > >> Database. > > Like OpenNMS or ZenOSS? > How can they be realtime if they generate static images? All images are static regardless of how much they pretend not to be. You can refresh as much as you like. But a graph shows a progression over time so there is always an interval. > >> 5. Technology I am thingking for web based application is Django and > >> Python as this web application can also be installed on Windows or > >> Linux based OS. > > If you want real-time monitoring you *must* build a service; a 'web app' > > can *not* do that. > Do you mean an agent? No, just use WMI over the wire. Agents are terrible, hard to develop, unreliable, and everyone hates agents. The systems already provide you access to the information you are talking about. > >> 6. Also please suggest which third party tool for chatrs and graphs I > >> should use with Django (open source + paid) > > ZenOSS and OpenNMS do graphs using RRD. > I know this is the "standard" but IMO it's totally backward these days. > Correlating or selecting/deselecting certain values is painful >(you have to write a graph def) How is it painful? Of course you have to create a graph definition - in your case you are creating a graph definition BY WRITING CODE! There couldn't be a more painful way to just create a graph. Have you used recent versions of ZenOSS? Graph definitions can be created right in the UI. > . With and modern JS libs like raphael > there are better ways to do this. Just look at google analytics. I've seen it. I don't see how it is "better". It's a graph. > It looks like PCP (http://oss.sgi.com/projects/pcp/features.html) will > gain a JSON interface shortly. That would be awesome because PCP is > developed by real engineers and has a proper architecture and is NOT a > CPU sucking monstrosity of PERL-line-noise + a few hacked-together PHP > frontends. I have no idea where the "PERL-line-noise + a few hacked-together PHP frontend" comment comes from. RRD is written in C. OpenNMS is Java and ZenOSS is Python/ZOPE. And as for "CPU sucking monstrosity" that is what everyone says... until they try to build a monitoring application... and thus create their own "CPU sucking monstrosity". This is a case of those-who-refuse-to-use-are-doomed-to-reinvent. -- http://mail.python.org/mailman/listinfo/python-list
Python wide-python-build unicode for Windows
Hi All, How could i increase the unicode range beyond 1 ? In python 2.5.4 by default the unicode range is 0x1, but in some cases i have unicode char beyond the limit. For those conditions it th an error. """File "E:\OpenERP\OpenERP AllInOne\Server\library.zip\reportlab\pdfbase\ttfonts.py", line 1197, in splitString ValueError: unichr() arg not in range(0x1) (narrow Python build)""" In Linux we can convert the "Narrow Python Build" to "Wide Python Build" using the command "--enable-unicode=ucs4 configures a wide Py_UNICODE" But how could i do this in Windows. Note: I used OpenERP All in one installer to install python 2.5. Thank you, -- SatheeshKumar. P +91 99446 38595 +91 87544 15303 sathe...@e-ndicus.com pskuma...@gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] From svn to something else?
On 04/29/2011 05:07 AM, Hans Georg Schaathun wrote: How easy and reliable is it to import my svn version history into one of the three big DVCS-s mentioned here? I'd say that one of the things SVN has going for it is that it's the lingua-franca of VCSes, so just about everything (especially the 3 big names mentioned in this thread: hg, bzr, git) can talk to svn pretty uneventfully. As a matter of fact, last I checked, Django is hosted in SVN, but most of the developers use DVCS tools to check in/out from the main repository to their own local hg/bzr/git repos, do their work locally (with the option to work offline, branch/merge easily, etc), and then push changesets back up when they have a patch they're happy with. -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: How to build an application in Django which will handle Multiple servers accross network
Hi, Am 29.04.2011 12:01, schrieb Adam Tauno Williams: On Thu, 2011-04-28 at 23:47 -0700, Anurag (anu) Agarwal wrote: Hi All, I want to build an application for one of my client which has following features 1. Client has some driver software which can be installed on Windows and Linux based systems. This driver software is fetching some operating system details using kernel level programming. This is commonly called an "agent". You might not want do write your own because it is hard to do correctly and takes a lot of time. I'd suggest you search for something like sigar (library) or collectd and check out what they can offer in terms of output formats. 2. Now a new web based application is required to moniter these servers remotly. This application will talk to these servers and get the data (not sure how data will be fetched from driver software) then show it on UI. Perhaps via WMI? Yes, best option. Modern windows versions have WinRM which is basically WMI over http (wmi being an implementation of CIM over DCOM, but I digress...) 3. The web based application will be used internally in the network to moniter servers in that network only. You mean like OpenNMS or ZenOSS? 4. Web based application will be a real time application with a Database. Like OpenNMS or ZenOSS? How can they be realtime if they generate static images? 5. Technology I am thingking for web based application is Django and Python as this web application can also be installed on Windows or Linux based OS. If you want real-time monitoring you *must* build a service; a 'web app' can *not* do that. Do you mean an agent? 6. Also please suggest which third party tool for chatrs and graphs I should use with Django (open source + paid) ZenOSS and OpenNMS do graphs using RRD. I know this is the "standard" but IMO it's totally backward these days. Correlating or selecting/deselecting certain values is painful (you have to write a graph def). With and modern JS libs like raphael there are better ways to do this. Just look at google analytics. On the other hand, RRD (the database) is great, I just never got the python bindings for rrd_fetch to reliably fetch the values I needed (you can't tell it to stop normalizing ) It looks like PCP (http://oss.sgi.com/projects/pcp/features.html) will gain a JSON interface shortly. That would be awesome because PCP is developed by real engineers and has a proper architecture and is NOT a CPU sucking monstrosity of PERL-line-noise + a few hacked-together PHP frontends. just my 2cents Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: How to build an application in Django which will handle Multiple servers accross network
On Thu, 2011-04-28 at 23:47 -0700, Anurag (anu) Agarwal wrote: > Hi All, > I want to build an application for one of my client which has > following features > 1. Client has some driver software which can be installed on Windows > and Linux based systems. This driver software is fetching some > operating system details using kernel level programming. > 2. Now a new web based application is required to moniter these > servers remotly. This application will talk to these servers and get > the data (not sure how data will be fetched from driver software) then > show it on UI. Perhaps via WMI? > 3. The web based application will be used internally in the network to > moniter servers in that network only. You mean like OpenNMS or ZenOSS? > 4. Web based application will be a real time application with a > Database. Like OpenNMS or ZenOSS? > 5. Technology I am thingking for web based application is Django and > Python as this web application can also be installed on Windows or > Linux based OS. If you want real-time monitoring you *must* build a service; a 'web app' can *not* do that. > 6. Also please suggest which third party tool for chatrs and graphs I > should use with Django (open source + paid) ZenOSS and OpenNMS do graphs using RRD. > If you guys can help me in desiging a very high level Architecture of > this application. Take a look at ZenOSS; copy what they did. > Thanks for reading so long. Please help me in this. If I am not clear > on something then please write back. -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] From svn to something else? (was: VCS tools)
Hmmm. I am still using svn. How easy and reliable is it to import my svn version history into one of the three big DVCS-s mentioned here? I am fairly happy with svn, but then I use it more as a backup system and a means to synchronise multiple systems. Something better would not hurt, but loosing the version history would ... I am particularly interested in git, not because of any qualities it may have but because that's what my colleague pushes, and he seems to be pushing our students into it, so it would be useful for me to be familiar with it. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: Composition instead of inheritance
Ben Finney wrote: Ethan Furman writes: Carl Banks wrote: That's not what we mean by composition. Composition is when one object calls upon another object that it owns to implement some of its behavior. Often used to model a part/whole relationship, hence the name. Hmmm. Okay -- any ideas for a better term? Something that describes taking different source classes and fusing them into a new whole, possibly using single-inheritance... Frankenstein, maybe? ;) (Remember that Frankenstein was not the monster, but the scientist.) “Hybrid”? Actualy this story is about the villagers being the monsters :o) JM -- http://mail.python.org/mailman/listinfo/python-list
Re: unpickling derived LogRecord in python 2.7 from python2.6
On Apr 28, 9:22 am, Peter Otten <__pete...@web.de> wrote: > Vinay Sajip wrote: > > On Apr 27, 5:41 pm, Peter Otten <__pete...@web.de> wrote: > > >> The Problem is that as of Python 2.7logging.LogRecord has become a > >> newstyle class which is pickled/unpickled differently. I don't know if > >> there is an official way to do the conversion, but here's what I've > >> hacked up. The script can read pickles written with 2.6 in 2.7, but not > >> the other way round. > >> [code snipped] > > > I don't know about "official", but another way of doing this is to > > pickle just the LogRecord's __dict__ and send that over the wire. The > > logging package contains a function makeLogRecord(d) where d is a > > dict. > > You are right, my approach is too complicated and only needed when the OP > cannot modify the sending script -- which is unlikely. > > > This is the approach used by the examples in the library documentation > > which pickle events for sending across a network: > > >http://docs.python.org/howto/logging-cookbook.html#sending-and-receiv... > > logging-events-across-a-network > > > > > The built-in SocketHandler pickles the LogRecord's __dict__ rather > > than the LogRecord itself, precisely because of the improved > > interoperability over pickling the instance directly. > > As a minimal change ensuring that the logging.LogRecord subclass used by the > OP is a newstyle class in 2.6 with > > class LogRecord(logging.LogRecord, object): > #... > > should work, too. I tried this, but it didn't work. Pickling the __dict__ and then use makeLogRecord does the trick. Thank you very much for the excellent help, Ian. -- http://mail.python.org/mailman/listinfo/python-list
