UK Python Conference - 19-20 April 2006
The ACCU is once again hosting a UK Python Conference on the above dates at the Randolph Hotel in Oxford. Sign up now. http://www.accu.org/index.php/conferences/2006/schedule PROGRAMME = I am happy to announce that Guido van Rossum is once again a keynote speaker for the entire ACCU conference. Following his keynote we have a single, 2-day Python track on Wednesday and Thursday including... Steve Holden: The Best of PyCon Michael Hudson: Error Handling with Recovery Phil Thompson: PyQT 4 Michael Hudson: PyPy - a progress report Simon Willison: Django Remi Delon: CherryPy and TurboGears Chris Withers: Templating systems Andy Robinson: Metadata and models in Python Andrew Thompson: Financial Programming in Python ...and of course lightning talks and BOFS will be welcome Friday 21st will feature a Dynamic Languages track with in-depth talks on Javascript, Ruby and Groovy, which I am sure will be of great interest to Python developers; and of course the dinner. PRE CONFERENCE PYTHON TUTORIAL: === John Pinner will be giving a full day Python for Programmers tutorial on Tuesday prior to the main event. This tutorial is aimed at programmers who have no previous knowledge of Python but who would like to know more about it. If you want to convert your colleagues, this is where to send them ABOUT THE ACCU CONFERENCE = For those not familiar with the event, the ACCU conference is one of the foremost gatherings of programming talent in the world, regularly featuring authors and major figures from the C/C++/C#/Java/Python and other communities.The cheapest way to attend is to join the ACCU This will be the LAST CHANCE to attend this fantastic event; after more than 5 years of being nurtured by the ACCU, the UK Python community will hopefully be organising a standalone conference in future years. Python talks will continue to be welcome (and we hope numerous) on the ACCU programme, but not as an advertised mini-conference; instead we'll be shifting focus to dynamic languages in general. Best Regards, Andy Robinson ACCU Conference Committee -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: different ways to strip strings
On Mon, 27 Feb 2006 13:28:44 -0500, rtilley wrote: s = ' qazwsx ' # How are these different? print s.strip() print str.strip(s) s.strip() strips white space from the start and end of string s. That is standard object-oriented behaviour: you have an instance, s, and you call its method, strip. str.strip(s) is a little more tricky, but not much. str is the built-in type for strings. Due to historical reasons, Python types and user-definable classes are slightly different, but at the level we're discussing here, you can imagine there is no difference. In effect, you can think of str.strip(s) as calling the strip method of the class (technically type) str, with s as the first argument. That is equivalent to calling the strip method of the instance s with no arguments. Do string objects all have the attribute strip()? Yes, via inheritance. That is, each string object doesn't have a copy of each method (strip, split, join, etc.) as that would be wasteful. The same goes for all objects in Python, including ints, floats, lists, as well as custom classes. Python's inheritance rules mean that: object_instance.method() and object_type.method(object_instance) are equivalent. If so, why is str.strip() needed? Because that is the machinery by which string objects get the attribute strip. Really, I'm just curious... there's a lot don't fully understand :) Gazing into my crystal ball, I'm going to answer your next question before you answer it. Use the form s.strip() in preference to str.strip(s). It is easier to read, faster, and generates smaller code. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: expat
Merci à Frederik et Jarek! According to your hints I did tests with a different coding and another option in OpenOffice 'Size optimization for XML format'. Went fine! - Back to my files from yesterday the same proper converting... uups Anyway, it's running! Katja -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Flash
SamFeltus enlightened us with: PS. Here is an example... http://sonomasunshine.com/sonomasunshine/FrontPage.html The HTML version of that site is crap, by the way. Check out http://sonomasunshine.com/cgi-bin/old_school.py?pagename=FrontPage The HTML is sent as text/plain, and if interpreted as HTML, it's not compliant with any HTML standard. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
HTML/DOM parser
is there a module that lets me parse validated html files and store it as a tree? for example, i want to be able to easily, say, replace the following hrpReferences/p pre • a href=aa.../a ... /pre to hrpReferences/p ul lia href=aa.../a/li ... /ul Thanks. Xah [EMAIL PROTECTED] ∑ http://xahlee.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: HTML/DOM parser
Xah Lee enlightened us with: is there a module that lets me parse validated html files and store it as a tree? http://docs.python.org/lib/module-xml.dom.html Assuming you're using XHTML. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Scientific Computing with NumPy
[EMAIL PROTECTED] wrote: Terry Reedy wrote: kpp9c [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Numeric, Numarray, Numpy... some one stick a screwdriver in my forehead and end the madness that Numeric has become. For crying all night! Numpy was Numeric's nickname Given that NumPy *is* an updated version of Numeric, with the same basic interface, I think the name quite appropriate. It also works well as a partner for SciPy. Exactly! I suppose people must vent, but the truth is that satisfying the diversity of scientific Python users is *very* hard. NumPy *is* trying to do something about the confusion between Numeric and Numarray. I'm sorry you don't like the name, but it was properly discussed and a host of other names were suggested before settling on NumPy as the *least bad*. Yes, it will be confusing for a few months, but then it will probably be *less* confusing as people realize that NumPy *is* Numeric 3K The interface is not that different. For example, you can usually compile extensions simply by replacing Numeric/arrayobject.h with numpy/arrayobject.h If you don't like things then start suggesting specific improvements at [EMAIL PROTECTED] instead of just ranting on the python list which most of us don't have the time to read anyway (notice how late I'm responding to this...) -Travis -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
Tim Chase wrote: ...throw UnthrowableKoan ... (okay...maybe it's a little too early on a weekdays.mon morning) Probably, since a SyntaxError slipped in. Throw is C++ Tim. It's raise UnRaisableKoan. -- http://mail.python.org/mailman/listinfo/python-list
Re: wxPython: help(wx) causes segfaulting?
Franz Steinhaeusler wrote: maybe you have 2.4.2 and I 2.4. This looks like a wxPython problem, not a Python problem. It might well be a version issue for you guys, but it's more likely that a certain wxPython version is the culprit, not a certain Python version. Note however that the OP is using Linux, where the wxWidgets uses completely different libraries, and that's where the problem occurs. Besides, it's not a Python exception in the Debian testing case, it's a segmentation fault in the underlying GLib code that causes Python to crash. BTW, Is the current Debian testing really equipped with Python 2.3.5? It's a very sorry state of affairs if the testing version of a major Linux release isn't using Python 2.4, which was released in November 2004. I can understand why people a leaving stock Debian for Ubuntu... -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Indentation Problems
[EMAIL PROTECTED] wrote:
I am a newbie to Python. I am mainly using Eric as the IDE for coding.
Also, using VIM and gedit sometimes.
I had this wierd problem of indentation. My code was 100% right but it
wont run because indentation was not right.
If indentation is not right, then your code is not 100% right !-)
I checked time and again
but still no success. I rewrote the code over again in VI and it ran.
Can you please explain whats the trick behind the correct indentation.
1/ use spaces not tabs. Hint : all decent code editors I know have a way
to configure this - just make sure all the editors you use have the
correct settings.
2/ preferably, stick to 4 spaces indent
3/ if you run into troubles, check the code with tabnanny:
http://effbot.org/librarybook/tabnanny.htm
Thanks
--
bruno desthuilliers
python -c print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])
--
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Re: newbie trying understand sys.path
MARK LEEDS wrote: So, as it said in Beginning Python, I went into my .bashrc file and did export PYTHONPATH=$PYTHONPATH:~/mytemp then, i typed pprint.pprint(sys.path) and it worked. it was in there but, now I want to take it out. i deleted the command from the .bashrc file and resourced it but it was still in there. removing the PYTHONPATH variable from the bashrc script won't remove the current value from the current environment. So, then I tried ( inside a python program ) sys.path = sys.path[1:] and it works inside the program so that sys.path changed while the program was running. but, then i checked it again, by taking out the above command and typing pprint.pprint(sys.path) and it was still there ? Basically, my question is : Is there a permanent way of taking things out of sys.path that you put in sort of by accident or for experimentation ? you can log out and log in again. or you can use export to set PYTHONPATH to whatever value you want it to have. or you can use unset PYTHONPATH to remove it from the environment: $ echo $PYTHONPATH $ export PYTHONPATH=spam $ echo $PYTHONPATH spam $ python -c import sys; print sys.path[:2] ['', '/home/fredrik/spam'] $ unset PYTHONPATH $ echo $PYTHONPATH $ python -c import sys; print sys.path[:2] ['', '/usr/local/lib/python2.5'] /F -- http://mail.python.org/mailman/listinfo/python-list
C++ OpenGL rendering, wxPython GUI?
I'm creating a scientific visualization application with rather high demands on performance. I've created a nice rendering engine for it in C++/OpenGL and a python interface to the rendering engine. Now I'm looking to build a GUI in python with the rendering engine as an integrated window. I will most likely use wxPython for the GUI and I know it has support for adding an OpenGL canvas. After looking around in these groups and others it seems to me that most people doing 3D-applications simply opt to use PyOpenGL. Since my application uses VBOs, shader programs and similar things this is not an option for me. My rendering engine currently uses GLUT for window handling, but what I want to do is to create the canvas in python for use with wxPython and then somehow toss it down to C++ for rendering and avoid using GLUT at all. I've yet to come across an example of how this could be done. Maybe including wxWidgets in the C++ program and just using the wxPython-created canvas ID there will somehow be possible? I'll look into that but any help or ideas are most welcome. Tobias Forslöw -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
on 28.02.2006 07:50 Carl Banks said the following:
Ben Finney wrote:
This PEP specifies an enumeration data type for Python.
[snip]
Here's why I think it's not too useful to begin with: the benefits of
the enum you describe here are pretty weak.
I need to disagree heavily here :)
+1 from me for the general idea of a builtin enum.
(and for 'real world' use cases: I use this type of enum, the PEP one,
in my code regularly)
It's a pretty weak case to have a dedicated builtin to prevent
duplicates in something that changes maybe once a month, as enums tend
to change rather slowly. (At least, that's the way enums in other
languages are used, and the design you present here seems to suggest
you intend to use them that way as well.) And frankly, a unit test or
assertion could check this.
[snip]
I don't understand what you mean by 'change rather slowly'?
The dominant use case for an explicit enum is to make it clear for the
code user that the values are a separate type, and prevent errors
occurring because the abused underlying type shows through (be it
strings or integers) or at least give informative warnings for them. If
you want more than that something, like a dict, will probably be better.
recent examples from this list:
2006-01-03: http://www.nabble.com/Re%3A-Regex-anomaly-p2179421.html
2006-02-20:
http://www.nabble.com/Re%3A-Regular-expression-gone-mad-p3029028.html
The nonsensical comparisions should throw value errors.
That's a valid point.
I hope someone knowledgeable will go through the standard library and
check each flag-like thing (which is not directly dependent on an
underlying c-library idiom) against the proposed enum type.
One thing that is probably missing to allow this, is a enum-set-creation
with the | operator::
Weekdays = enum('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
daysihate = Weekdays.mon | Weekdays.thu
(and this discussion needs to move to python-dev ?)
As for the metaclass versions: For myself, the above version feels more
natural and straightforward (in the same way as the PEP author describes
it), though I understand the subclassing ideas.
But are there use cases for subclassing, that aren't better served with
a new enum or something homegrown?
Can C++/Pascal/Java enums be subclassed?
cheers,
stefan
--
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Fetching the Return results of a spawned Thread
Is there any way to fetch the Return results of spawned threads within the parent script? I would like to do that because I'm having problems with Threads that do queries to a database, I often encounter Threads failing due to MySQL connection failures. As much as possible I plan to make the threads return the query string and let the parent script do the actual query. Thanks in advance. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fetching the Return results of a spawned Thread
Alvin A. Delagon wrote: Is there any way to fetch the Return results of spawned threads within the parent script? I would like to do that because I'm having problems with Threads that do queries to a database, I often encounter Threads failing due to MySQL connection failures. As much as possible I plan to make the threads return the query string and let the parent script do the actual query. Thanks in advance. use a shared Queue object, let the worker threads write their result to this queue, and let the parent thread poll the queue: http://docs.python.org/lib/module-Queue.html /F -- http://mail.python.org/mailman/listinfo/python-list
Re: sort one list using the values from another list
_ is just a plain variable name in Python. It is sometimes when a variable is needed to receive a value that won't be used. Like in some other interactive systems (Mathematica, etc, but with a different syntax) _ has a use in the interactive shell, it contains the last unassigned result: a = 2 * 5 _ Traceback (most recent call last): File interactive input, line 1, in ? NameError: name '_' is not defined 2 * 5 10 _ 10 Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: bsddb3 database file, are there any unexpected file size limits occuring in practice?
Klaas wrote: Claudio writes: I am on a Windows using the NTFS file system, so I don't expect problems with too large file size. how large can files grow on NTFS? I know little about it. No practical limit on current harddrives. i.e.: Maximum file size Theory: 16 exabytes minus 1 KB (2**64 bytes minus 1 KB) Implementation: 16 terabytes minus 64 KB (2**44 bytes minus 64 KB) Maximum volume size Theory:2**64 clusters minus 1 Implementation: 256 terabytes minus 64 KB (2**32 clusters minus 1) Files per volume 4,294,967,295 (2**32 minus 1 file) (I suppose it in having only 256 MB RAM available that time) as it is known that MySQL databases larger than 2 GByte exist and are in daily use :-( . Do you have more ram now? I have now 3 GByte RAM on my best machine, but Windows allows a process not to exceed 2 GByte, so in practice a little bit less than 2 GByte are the actual upper limit. I've used berkeley dbs up to around 5 gigs in size and they performed fine. However, it is quite important that the working set of the database (it's internal index pages) can fit into available ram. If they are swapping in and out, there will be problems. Thank you very much for your reply. In my current project I expect the data to have much less volume than the indexes. In my failed MySQL project the size of the indexes was appr. same as the size of the indexed data (1 GByte). In my current project I expect the total size of the indexes to exceed by far the size of the data indexed, but because Berkeley does not support multiple indexed columns (i.e. only one key value column as index) if I access the database files one after another (not simultaneously) it should work without problems with RAM, right? Do the data volume required to store the key values have impact on the size of the index pages or does the size of the index pages depend only on the number of records and kind of the index (btree, hash)? In last case, I were free to use for the key values also larger sized data columns without running into the problems with RAM size for the index itself, else I were forced to use key columns storing a kind of hash to get their size down (and two dictionaries instead of one). What is the upper limit of number of records in practice? Theoretical, as given in the tutorial, Berkeley is capable of holding up to billions of records with sizes of up to 4 GB each single record with tables up to total storage size of 256 TB of data. By the way: are billions in the given context multiple of 1.000.000.000 or of 1.000.000.000.000 i.e. in US or British sense? I expect the number of records in my project in the order of tens of millions (multiple of 10.000.000). I would be glad to hear if someone has already successful run Berkeley with this or larger amount of records and how much RAM and which OS had the therefore used machine (I am on Windows XP with 3 GByte RAM). Claudio -Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
Stefan Rank wrote:
on 28.02.2006 07:50 Carl Banks said the following:
Ben Finney wrote:
This PEP specifies an enumeration data type for Python.
[snip]
Here's why I think it's not too useful to begin with: the benefits of
the enum you describe here are pretty weak.
I need to disagree heavily here :)
the benefits of the enum you describe here [beyond my example which I
claimed enum was only a minor improvement over] are pretty weak.
It's a pretty weak case to have a dedicated builtin to prevent
duplicates in something that changes maybe once a month, as enums tend
to change rather slowly. (At least, that's the way enums in other
languages are used, and the design you present here seems to suggest
you intend to use them that way as well.) And frankly, a unit test or
assertion could check this.
[snip]
I don't understand what you mean by 'change rather slowly'?
Construct data structure on-the-fly from an XML file edited by multiple
people every day = changes rather quickly
Construct data structure from a Python file that was last edited a year
and a half ago = changes rather slowly
Typically, enums fall into the latter category. You set the enum
values, and then pretty much leave them alone, adding new values only
occasionally. (Come on, how often do the days of the week change?)
All I was saying is, changes to the enum values are infrequent enough
that having a special type just to make sure there are no duplicates is
a waste. The only justification for a built-in enum is the other stuff
you mentioned.
One thing that is probably missing to allow this, is a enum-set-creation
with the | operator::
Weekdays = enum('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
daysihate = Weekdays.mon | Weekdays.thu
(and this discussion needs to move to python-dev ?)
What's wrong with set((Weekdays.mon,Weekdays.thu))? Explicit is better
than implicit.
As for the metaclass versions: For myself, the above version feels more
natural and straightforward (in the same way as the PEP author describes
it), though I understand the subclassing ideas.
But are there use cases for subclassing, that aren't better served with
a new enum or something homegrown?
Can C++/Pascal/Java enums be subclassed?
In C++, enum is a type but not a class. Same thing with Ada. Java
didn't have enums last time I checked. Don't know about Pascal. I
didn't care too much about subclassing; I just thought different enum
constant that couldn't (or, rather, oughtn't) be compared probably
should be instances of a separate class. It doesn't matter much,
though.
Should something like this work:
day = Weekdays.mon
isinstance(day,Weekdays)
?
Carl Banks
--
http://mail.python.org/mailman/listinfo/python-list
Printing a file
Hello! I am currently working on an application where the user is able to create new worksheets and to delete existing ones. All of these worksheets have the same structure (-- template?), only some values should be changed. A minimal example would be something like this: Name: ... Role: Address: The values are stored in a SQLite database. Now I would like to offer the possibility to print out a single record on a DinA4 paper. In order to do this, the dots (...) above of course have to be replaced by the current record's values and the different parts have to fit on one page. Unfortunately I don't know how to realize this, since also some images and different boxes should be printed out. As the whole application is based on QT, QPrinter might be used, but I couldn't find any examples how to use it. What do you suggest? Which format should the template have? (XML, etc.?) Any hints appreciated! Cheers, Fabian Steiner -- http://mail.python.org/mailman/listinfo/python-list
Re: Printing a file
Fabian Steiner wrote: Unfortunately I don't know how to realize this, since also some images and different boxes should be printed out. As the whole application is based on QT, QPrinter might be used, but I couldn't find any examples how to use it. QPrinter is easy to use. You just draw to the page the same way as you talk to the screen with a QPainter. prnt = qt.QPrinter() # you can also vary options like colour, doc name, dpi here # display dialog box to user (you can actually leave this out) if prnt.setup(): painter = qt.QPainter() painter.begin(printer) # do stuff to draw to painter painter.end(printer) # do this between each page printer.newPage() # ... more pages can be printed to a painter It's very easy to do. If you want to handle multiple pages and so on, there's a bit of work to do to interface to the dialog to get the user-selected page range, etc. Jeremy -- Jeremy Sanders http://www.jeremysanders.net/ -- http://mail.python.org/mailman/listinfo/python-list
Re: C++ OpenGL rendering, wxPython GUI?
[EMAIL PROTECTED] wrote: I'm creating a scientific visualization application with rather high demands on performance. I've created a nice rendering engine for it in C++/OpenGL and a python interface to the rendering engine. Now I'm looking to build a GUI in python with the rendering engine as an integrated window. I will most likely use wxPython for the GUI and I know it has support for adding an OpenGL canvas. After looking around in these groups and others it seems to me that most people doing 3D-applications simply opt to use PyOpenGL. Since my application uses VBOs, shader programs and similar things this is not an option for me. My rendering engine currently uses GLUT for window handling, but what I want to do is to create the canvas in python for use with wxPython and then somehow toss it down to C++ for rendering and avoid using GLUT at all. I've yet to come across an example of how this could be done. Maybe including wxWidgets in the C++ program and just using the wxPython-created canvas ID there will somehow be possible? I'll look into that but any help or ideas are most welcome. You should be able to create and realize the OpenGL canvas (which will create an OpenGL context), then make the OpenGL calls from C++ without any worries. Realizing (i.e., creating the window for) the canvas would create the OpenGL context, and somewhere along the way the context gets bound (probably during the canvas's draw callback). BTW, though you can't use PyOpenGL for the VBO stuff, it might be useful to install it anyways to do high-level stuff (set up flags, position the camera, etc.). Calls from C and PyOpenGL can be freely mixed. I've done similar things in GTK on Linux. I had a gtkglarea canvas, PyOpenGL, and my own C extension all making OpenGL calls. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Printing a file
Jeremy Sanders wrote: Fabian Steiner wrote: Unfortunately I don't know how to realize this, since also some images and different boxes should be printed out. As the whole application is based on QT, QPrinter might be used, but I couldn't find any examples how to use it. [...] It's very easy to do. If you want to handle multiple pages and so on, there's a bit of work to do to interface to the dialog to get the user-selected page range, etc. That's where QPrintDialog comes in: http://doc.trolltech.com/4.1/qprintdialog.html It's also secretly available in Qt 3 via the QPrinter.setup() method: printer = QPrinter() printer.setup() # Now, paint onto the printer as usual. David -- http://mail.python.org/mailman/listinfo/python-list
Re: Python advocacy in scientific computation
In article [EMAIL PROTECTED], Georg Brandl [EMAIL PROTECTED] wrote: Michael Tobis wrote: Someone asked me to write a brief essay regarding the value-add proposition for Python in the Fortran community. Slightly modified to remove a few climatology-related specifics, here it is. Great text. Do you want to put it onto a Wiki page at wiki.python.org? . . . URL: http://wiki.python.org/moin/PythonAdvocacyInScientificComputation -- http://mail.python.org/mailman/listinfo/python-list
Multicolumn in Tix scrolledListBox
hi iam using Tix ScrolledListBox widget. is there any option so that i can disply the items in multiple colums thanks Anil -- http://mail.python.org/mailman/listinfo/python-list
Re: Fetching the Return results of a spawned Thread
Alvin A. Delagon wrote: Is there any way to fetch the Return results of spawned threads within the parent script? There are several examples of this in the threading section of the Python Cookbook for example http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/84317 http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/435883 Kent -- http://mail.python.org/mailman/listinfo/python-list
Multicolumn in Tix scrolledListBox
hi iam using Tix ScrolledListBox widget. is there any option so that i can disply the items in multiple colums thanks Anil -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
What about that?
SomeNumbers = enum('0', '1', '2', '3', '4', '5', '6', '7')
or
Rooms = enum('1bed', '2beds', 'moreThan2beds')
or even
Comments = enum('#', ';', '//')
CyrilOn 28 Feb 2006 03:14:25 -0800, Carl Banks [EMAIL PROTECTED] wrote:
Stefan Rank wrote: on 28.02.2006 07:50 Carl Banks said the following: Ben Finney wrote: This PEP specifies an enumeration data type for Python. [snip]
Here's why I think it's not too useful to begin with: the benefits of the enum you describe here are pretty weak. I need to disagree heavily here :)the benefits of the enum you describe here [beyond my example which I
claimed enum was only a minor improvement over] are pretty weak. It's a pretty weak case to have a dedicated builtin to prevent duplicates in something that changes maybe once a month, as enums tend
to change rather slowly.(At least, that's the way enums in other languages are used, and the design you present here seems to suggest you intend to use them that way as well.)And frankly, a unit test or
assertion could check this. [snip] I don't understand what you mean by 'change rather slowly'?Construct data structure on-the-fly from an XML file edited by multiplepeople every day= changes rather quickly
Construct data structure from a Python file that was last edited a yearand a half ago = changes rather slowlyTypically, enums fall into the latter category.You set the enumvalues, and then pretty much leave them alone, adding new values only
occasionally.(Come on, how often do the days of the week change?)All I was saying is, changes to the enum values are infrequent enoughthat having a special type just to make sure there are no duplicates is
a waste.The only justification for a built-in enum is the other stuffyou mentioned. One thing that is probably missing to allow this, is a enum-set-creation with the | operator::Weekdays = enum('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
daysihate = Weekdays.mon | Weekdays.thu (and this discussion needs to move to python-dev ?)What's wrong with set((Weekdays.mon,Weekdays.thu))?Explicit is betterthan implicit.
As for the metaclass versions: For myself, the above version feels more natural and straightforward (in the same way as the PEP author describes it), though I understand the subclassing ideas.
But are there use cases for subclassing, that aren't better served with a new enum or something homegrown? Can C++/Pascal/Java enums be subclassed?In C++, enum is a type but not a class.Same thing with Ada.Java
didn't have enums last time I checked.Don't know about Pascal.Ididn't care too much about subclassing; I just thought different enumconstant that couldn't (or, rather, oughtn't) be compared probablyshould be instances of a separate class.It doesn't matter much,
though.Should something like this work:day = Weekdays.monisinstance(day,Weekdays)?Carl Banks--http://mail.python.org/mailman/listinfo/python-list
--
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Vectorization and Numeric (Newbie)
Assume you have a mathematical function, e.g. f(x) = x + 4 To calculate all the values from 1 to n, a loop is one alternative. But to make this function work with vectors instead i.e f(x_vector) = result_vector, how should the function then be implemented? Thanks RM -- Support bacteria - it's the only culture some people have! -- http://mail.python.org/mailman/listinfo/python-list
compiled program input
i have a compiled program named m.exe. when i execute it asks me to enter a parameter like me.dat. the coder didn't manage the argv for this program and i only have the executable. is there a vay to call this executeable from python and give parameters to it? m.exe input1 ? me.dat something like this -- http://mail.python.org/mailman/listinfo/python-list
Re: Vectorization and Numeric (Newbie)
Are you looking for the map function? def f(x): return x+4 map(f, [1,2,3,3,70]) [5, 6, 7, 7, 74] CyrilOn 2/28/06, Ronny Mandal [EMAIL PROTECTED] wrote: Assume you have a mathematical function, e.g. f(x) = x + 4To calculate all the values from 1 to n, a loop is one alternative.But to make this function work with vectors instead i.ef(x_vector) = result_vector, how should the function then be implemented?ThanksRM--Support bacteria - it's the only culture some people have!--http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: PyQT: QDialog and QMainWindow interacting with each other
Fabian Steiner schrieb: MyDialog is closed by calling MyDialog.accept(). What can I do so that self.showListViewItems() is called after MyDialog has been closed? Thank you for any input! Hi Fabian, override the accept() method and call self.showListViewItems() there. But remember to call QDialog.accept() at the end. def accept( self ): self.showListViewItems() QDialog.accept( self ) Kai Teuber -- http://mail.python.org/mailman/listinfo/python-list
Re: compiled program input
i found something like import os os.system(c\\m.exe) but it gives An endfile record was detected in a READ statement (unit=40). Error occurs at or near line 51 of _MAIN__ 12 still don't have anything :( -- http://mail.python.org/mailman/listinfo/python-list
Re: compiled program input
[EMAIL PROTECTED] wrote: i have a compiled program named m.exe. when i execute it asks me to enter a parameter like me.dat. the coder didn't manage the argv for this program and i only have the executable. is there a vay to call this executeable from python and give parameters to it? m.exe input1 ? me.dat something like this does echo me.dat | m.exe work ? /F -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
It seems the concensus is that empty enums should be allowed for consistancy, and to support the loop that doesn't. I thought I'd find some data points in other languages as a guide: * C - builtin, empty enumerations not allowed * C++ - builtin, empty enumerations allowed. C++ doesn't have iteration over a enumeration, except as a side-effect of direct translation from elements to integerts (and then, only for a sequentially assigned enumeration). An enumeration is a type, so it can be thrown (raised) as an exception - http://oopweb.com/CPP/Documents/CPPAnnotations/Volume/cplusplus16.html#EMPTYENUM * Java - builtin, empty enumerations allowed previously to 1.5, but maybe not after - http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5081785 * OCaml - library, empty enumerations allowed as a consequence of being able to add and remove enumeration elememts: http://ocaml-lib.sourceforge.net/doc/Enum.html I realize this is a strange and short list, but it's all I can do with 5 min of Google and a little testing. -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
on 28.02.2006 12:14 Carl Banks said the following:
[snip]
It's a pretty weak case to have a dedicated builtin to prevent
duplicates in something that changes maybe once a month, as enums tend
to change rather slowly. (At least, that's the way enums in other
languages are used, and the design you present here seems to suggest
you intend to use them that way as well.) And frankly, a unit test or
assertion could check this.
[snip]
I don't understand what you mean by 'change rather slowly'?
Construct data structure on-the-fly from an XML file edited by multiple
people every day = changes rather quickly
Construct data structure from a Python file that was last edited a year
and a half ago = changes rather slowly
Typically, enums fall into the latter category. You set the enum
values, and then pretty much leave them alone, adding new values only
occasionally. (Come on, how often do the days of the week change?)
All I was saying is, changes to the enum values are infrequent enough
that having a special type just to make sure there are no duplicates is
a waste. The only justification for a built-in enum is the other stuff
you mentioned.
agreed
One thing that is probably missing to allow this, is a enum-set-creation
with the | operator::
Weekdays = enum('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
daysihate = Weekdays.mon | Weekdays.thu
(and this discussion needs to move to python-dev ?)
What's wrong with set((Weekdays.mon,Weekdays.thu))? Explicit is better
than implicit.
agreed again.
the | idea would only be for (interface) backwards compatibility.
As for the metaclass versions: For myself, the above version feels more
natural and straightforward (in the same way as the PEP author describes
it), though I understand the subclassing ideas.
But are there use cases for subclassing, that aren't better served with
a new enum or something homegrown?
Can C++/Pascal/Java enums be subclassed?
In C++, enum is a type but not a class. Same thing with Ada. Java
didn't have enums last time I checked. Don't know about Pascal.
Was more of a question for subclassing use cases in other languages.
BTW Java has an enum now, which cannot be subclassed either AFAIK. And
it's the same for (Delphi) Pascal.
I
didn't care too much about subclassing; I just thought different enum
constant that couldn't (or, rather, oughtn't) be compared probably
should be instances of a separate class. It doesn't matter much,
though.
Should something like this work:
day = Weekdays.mon
isinstance(day,Weekdays)
?
I think in the PyPI package `type(Weekdays)` is `Enum` and
`type(Weekdays.mon)` is `EnumValue`, so this would not work.
But membership testing `if day in Weekdays: ...` could do the same, and
type-checking for enum values `isinstance(day, EnumValue)` would work
(might be unpythonic though).
In the cookbook recipe `enum('..')` is a function and constructs two new
types on the fly, so the values of two different enums would be of a
different type, but you would not be able to name it easily...
cheers
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Re: Vectorization and Numeric (Newbie)
Ronny Mandal wrote: Assume you have a mathematical function, e.g. f(x) = x + 4 To calculate all the values from 1 to n, a loop is one alternative. Numeric and friends (numarray,numpy) have something like numarray.arange - they return arrays similar to the lists returned by standard libs range function. I would recommend using the built-in array operations as much as possible - in most cases they are much faster than looping, and your code remains simpler. But to make this function work with vectors instead i.e f(x_vector) = result_vector, how should the function then be implemented? In most numeric libraries, vectors and scalars can be added etc. For the simple f(x) case you can use just the simplest approach: def f(x): return x+4 and call this with scalar and vector args. f_pi = f(3.14159265) f_1to200 = f(numarray.arange(1,200)) -- http://mail.python.org/mailman/listinfo/python-list
Re: C++ OpenGL rendering, wxPython GUI?
On 28 Feb 2006 01:14:15 -0800 [EMAIL PROTECTED] wrote: I'm creating a scientific visualization application with rather high demands on performance. I've created a nice rendering engine for it in C++/OpenGL and a python interface to the rendering engine. Now I'm looking to build a GUI in python with the rendering engine as an integrated window. I will most likely use wxPython for the GUI and I know it has support for adding an OpenGL canvas. Maybe including wxWidgets in the C++ program and just using the wxPython-created canvas ID there will somehow be possible? I'll look into that but any help or ideas are most welcome. I banged my head on this for quite a while trying to integrate OpenInventor and wxPython (and later PyGTKGLext). Basically, the OpenGL callers don't need to know what the current canvas is. You tell the canvas to activate itself, it tells OpenGL hey, I'm the current canvas now. Then OpenGL commands draw themselves on that canvas. It's really much simpler than I initially thought. You just have to make sure that there's a Python function somewhere in your begin-rendering sequence that activates the canvas before OpenGL calls begin. - Michael -- mouse, n: a device for pointing at the xterm in which you want to type. -- Fortune -- http://mail.python.org/mailman/listinfo/python-list
Re: compiled program input
:) yes it does. thank you very much fredrick. -- http://mail.python.org/mailman/listinfo/python-list
ANN: Leo 4.4a7 released
Leo 4.4 alpha 7 is now available at: http://sourceforge.net/project/showfiles.php?group_id=3458package_id=29106 This version fixes some minor problems with Leo 4.4a6 and adds autocompletion and calltips. There are no known problems with this release. It may be better than beta quality. Or not. Leo is a text editor, data organizer, project manager and much more. See: http://webpages.charter.net/edreamleo/intro.html The highlights of Leo 4.4: -- - An Emacs-like mini-buffer: you can now execute any command by typing its long name, with tab completion. - Many new commands, including cursor and screen movement, basic character, word and paragraph manipulation, and commands to manipulate buffers, the kill ring, regions and rectangles. You can use Leo without using a mouse. - Flexible key bindings and input modes. You can emulate the operation of Emacs, Vim, or any other editor. - A tabbed log pane. The Find and Spell Check commands now use tabs instead of dialogs, making those commands much easier to use. Plugins or scripts can easily create new tabs. The Completion tab shows possible typing completions. - Autocompletion and calltips. - Dozens of other new features and bug fixes since Leo 4.3.3. Quote of the month: --- Thanks for a wonderful program - everybody should be using it! It blows the socks off that Java Mind mapping software that won project of the month a while back on sourceforge! -- Derick van Niekerk. Links: -- Leo: http://webpages.charter.net/edreamleo/front.html Home: http://sourceforge.net/projects/leo/ Download: http://sourceforge.net/project/showfiles.php?group_id=3458 CVS: http://sourceforge.net/cvs/?group_id=3458 Quotes: http://webpages.charter.net/edreamleo/testimonials.html Edward Edward K. Ream email: [EMAIL PROTECTED] Leo: http://webpages.charter.net/edreamleo/front.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Firebird and Python
Ray Cote wrote: At 5:07 PM +0100 2/27/06, Magnus Lycka wrote: SNIP I'm still interested in experiences from Pythonistas using Firebird-- especially embedded. Works great. Python and Firebird embedded (at least on Windows) is very simple to use. Not currently using it on other platforms. --Ray May I ask what do I need to use embedded Firebird from Python on Windows? Which Firebird download (http://www.firebirdsql.org/download/prerelease/win32/Firebird-2.0.0.12169-0_embed_win32.zip ?) and which Python module (http://kinterbasdb.sourceforge.net/ ?) Do I understand it right, that I can use Firebird database in the same way as I can use the Berkeley one provided in Python standard distribution? Claudio -- http://mail.python.org/mailman/listinfo/python-list
Deleting items from Tix Tree
hi iam using Tix tree widget in my python script. how can i delete the entire tree. i tried the following self.msgTree = Tix.Tree(self.msgWin) self.msgTree.hlist.delete() but it thorws the following error self.msgTree.hlist.delete() File /usr/local/lib/python2.2/lib-tk/Tix.py, line 320, in __getattr__ raise AttributeError, name AttributeError: delete can some one help me thanks Anil -- http://mail.python.org/mailman/listinfo/python-list
Re: HTML/DOM parser
On 28 Feb 2006 00:33:11 -0800 Xah Lee [EMAIL PROTECTED] wrote: is there a module that lets me parse validated html files and store it as a tree? BeautifulSoup will parse valid HTML (not just XHTML), and also crummy HTML while it's at it. And generates a tree structure. Warning: I haven't actually used this myself, I've just looked at it. http://www.crummy.com/software/BeautifulSoup/ - Michael -- mouse, n: a device for pointing at the xterm in which you want to type. -- Fortune -- http://mail.python.org/mailman/listinfo/python-list
UK Python Conference - 19-20 April 2006
The ACCU is once again hosting a UK Python Conference on the above dates at the Randolph Hotel in Oxford. Sign up now. http://www.accu.org/index.php/conferences/2006/schedule PROGRAMME = I am happy to announce that Guido van Rossum is once again a keynote speaker for the entire ACCU conference. Following his keynote we have a single, 2-day Python track on Wednesday and Thursday including... Steve Holden: The Best of PyCon Michael Hudson: Error Handling with Recovery Phil Thompson: PyQT 4 Michael Hudson: PyPy - a progress report Simon Willison: Django Remi Delon: CherryPy and TurboGears Chris Withers: Templating systems Andy Robinson: Metadata and models in Python Andrew Thompson: Financial Programming in Python ...and of course lightning talks and BOFS will be welcome Friday 21st will feature a Dynamic Languages track with in-depth talks on Javascript, Ruby and Groovy, which I am sure will be of great interest to Python developers; and of course the dinner. PRE CONFERENCE PYTHON TUTORIAL: === John Pinner will be giving a full day Python for Programmers tutorial on Tuesday prior to the main event. This tutorial is aimed at programmers who have no previous knowledge of Python but who would like to know more about it. If you want to convert your colleagues, this is where to send them ABOUT THE ACCU CONFERENCE = For those not familiar with the event, the ACCU conference is one of the foremost gatherings of programming talent in the world, regularly featuring authors and major figures from the C/C++/C#/Java/Python and other communities.The cheapest way to attend is to join the ACCU This will be the LAST CHANCE to attend this fantastic event; after more than 5 years of being nurtured by the ACCU, the UK Python community will hopefully be organising a standalone conference in future years. Python talks will continue to be welcome (and we hope numerous) on the ACCU programme, but not as an advertised mini-conference; instead we'll be shifting focus to dynamic languages in general. Best Regards, Andy Robinson ACCU Conference Committee -- http://mail.python.org/mailman/listinfo/python-list
comple list slices
Hi,
I have a list of rows which contains a list of cells (from a html table), and I
want to create an array of logical row groups (ie group rows by the rowspan). I
am only concerned with checking the rowspan of specific columns, so that makes
it easier, but I am having trouble implementing it in python. In perl/c I could
use a for loop and modify the control variable as I walked the array:
my (@rowgroups);
for (my ($i) = 0; $i $#rows; $i++) {
my ($rowspan) = $rows[$i][0]-attr(rowspan) || 1;
$rowspan--; # 0 indexed
push @rowgroups, $rows[$i .. $i+$rowspan];
$i += $rowspan;
}
but in python I can only come up with this:
rowgroups = []
rowspan = 0
for i in rows:
if rowspan 0:
rowspan -= 1
continue
rowspan = rows[j][0][rowspan] or 1
rowgroups.append(rows[ rows.index(i) : rows.index(i) + rowspan ])
rowspan -= 1
I really dont like this solution. Any ideas?
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Re: Python and Flash
I aint a professional coder, but a gardener. However, the Flash-JSON-Python technique works. It is poorly coded, but it is IMO a very simple way to integrate Flash and Python compared to the methods normally suggested on the net. The HTML is just some junk thrown up for people with lower tech browsers without much thought or consideration. -- http://mail.python.org/mailman/listinfo/python-list
error: argument after ** must be a dictionary
I have class like this...
import threading
class MyBlah(object):
def __init__(self):
self.makeThread(self.blah, (4,9))
def blah(self, x, y):
print X and Y:, x, y
def makeThread(self, func, args=(), kwargs={}):
threading.Thread(target=self.blah, args=args,
kwargs=kwargs).start()
When I do...
b = MyBlah()
I am getting this error:
TypeError: MyBlah object argument after ** must be a dictionary
What am I missing?
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Re: error: argument after ** must be a dictionary
abcd [EMAIL PROTECTED] wrote:
I have class like this...
import threading
class MyBlah(object):
def __init__(self):
self.makeThread(self.blah, (4,9))
def blah(self, x, y):
print X and Y:, x, y
def makeThread(self, func, args=(), kwargs={}):
threading.Thread(target=self.blah, args=args,
kwargs=kwargs).start()
When I do...
b = MyBlah()
I am getting this error:
TypeError: MyBlah object argument after ** must be a dictionary
I'm getting
X and Y: 4 9
are you sure you posted the right code ?
where's the rest of the traceback, btw ?
/F
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Get my airlines boarding pass
Hi all, Has any of you fine geniuses figured out a nice python script to go to the Southwest airlines website and check in, and retrieve your boarding pass - automatically 24 hours in advance -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
A couple questions: 1- what is j? 2- what does the rows[x][y] object look like? I assume it's a dict that has a rowspan key. Can rows[x][y][rowspan] sometimes be 0? Perhaps you're looking for something like this: rowgroups = [] rowspan = 0 for i in range( len(rows) ): if rowspan = 0: rowspan = rows[j][0][rowspan] if rowspan == 0: rowspan = 1 rowgroups.append(rows[ i : i + rowspan ]) rowspan -= 1 -sjbrown -- http://mail.python.org/mailman/listinfo/python-list
Re: Python advocacy in scientific computation
Maybe I'd also emphasize the nice COM interface that allow your wrapped Fortran to be made available in your Excel macros in a snap. It happens that Fortran programmers/users tends to be poor Office users except for Excel which they master at unbelievable level... My own best low work/high user satisfaction ever is just this, wrap LOWTRAN call to make is usable from Excel, a 1/2h work and a 100+ users 2 days later ! -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
Ben Finney wrote: This PEP specifies an enumeration data type for Python. An enumeration is an exclusive set of symbolic names bound to arbitrary unique values. Values within an enumeration can be iterated and compared, but the values have no inherent relationship to values outside the enumeration. -1 on the proposal as-is. I don't have many use cases for enumerations, and I don't think they merit appearing in the builtins. If you put them in the collections module instead, I'd probably be +0. This allows the operation to succeed, evaluating to a boolean value:: gym_night = Weekdays.wed gym_night Weekdays.mon False gym_night Weekdays.wed False gym_night Weekdays.fri True gym_night 23 False gym_night 23 True gym_night wed True gym_night Grades.B True For the few cases of enumerations that I've needed, I've never wanted them to be comparable with , , etc. If there were two classes, say ``collections.Enum`` and ``collections.OrderedEnum`` where only the latter made the enumerated items comparable, you might even get me as high as +0.5. (I only care about the non-comparable one, but I understand that others may have a need for the comparable one.) STeVe -- http://mail.python.org/mailman/listinfo/python-list
Re: Firebird and Python
Claudio Grondi wrote: Do I understand it right, that I can use Firebird database in the same way as I can use the Berkeley one provided in Python standard distribution? That depends on what you mean by the same way... As with Berkeley, you can use it in-process, and don't need a separate server process. On the other hand, it's a full SQL database, not a persistent mapping as Berkeley DB etc. It's better to compare it with SQLite, but it's not as lite. That is, it support more of the SQL standards. Firebird can also be used as a database server, not just as an embedded database. -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
Python lets you iterate through a list using an integer index, too,
although if you do so we will make fun of you. You can accomplish it
with a while loop, as in:
i = 0
while i len(rows):
if rows[i] == This code looks like BASIC without the WEND, doesn't
it?:
rowgroups.append(Pretty much.)
i += 1 # or i += rowspan, whatever.
Do not try to do this with a for loop. In Python, for i in xrange(5)
is more like a foreach $i ( {0,1,2,3,4,5}) in Perl, so changing i in
the loop will not change the value of i on the next loop iteration.
--
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Re: time.sleep(1) sometimes runs for 200 seconds under windows
Magnus Lycka wrote: On Windows that it. At least on Linux and Solaris, time.clock() returns CPU time. If time.clock() returns significantly different values before and after time.sleep(1), there's something seriously broken in sleep on such platforms. No! When process run the sleep, the operating system give other processes to run and it takes time (so called time slice) to get back to the original process. Recently I invoked Runtime.sleep() from Java on Centos 4.2 and it might take up to 1 sec(!) to come from the sleep no matter what you put as the sleep parameter. Basically each process runs for around 20ms and then the other process get priority. I'm not sure why those Codecs run OK when I watch DVD movie while running other Java application which use processor and hard disc quite intensivly, it seems that they got slices regulary, I'm not sure way. So, once more when you go to sleep other process get the slice so it could take more time then predicted to continue. -- Mladen Adamovic http://home.blic.net/adamm http://www.shortopedia.com http://www.froola.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Vectorization and Numeric (Newbie)
map takes a function and a list, applies the function to each item in a list, and returns the result list. For example: def f(x): return x + 4 numbers = [4, 8, 15, 16, 23, 42] map(f, numbers) [8, 12, 19, 20, 27, 46] So, rather that ask if there is a different way to write f, I'd just use f in a different way. Another way to accomplish the same result is with a list comprehension: [f(x) for x in numbers] [8, 12, 19, 20, 27, 46] As you can see, if you wanted to calculate all the values from 1 to n, you could also use these techniques instead of a loop. n = 10 [f(x) for x in xrange(1, n+1)] [5, 6, 7, 8, 9, 10, 11, 12, 13, 14] -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
shandy.b at gmail.com writes: A couple questions: 1- what is j? 2- what does the rows[x][y] object look like? I assume it's a dict that has a rowspan key. Can rows[x][y][rowspan] sometimes be 0? Perhaps you're looking for something like this: rowgroups = [] rowspan = 0 for i in range( len(rows) ): if rowspan = 0: rowspan = rows[j][0][rowspan] if rowspan == 0: rowspan = 1 rowgroups.append(rows[ i : i + rowspan ]) rowspan -= 1 -sjbrown oops, typo row[j] should be i that line should read: rowspan = i[0][rowspan] rows is a list of lists which contains td tag objects from beautifulsoup. rowspan is a tag attribute. You solution is clearer then mine, but the approach is the same. Is there finer grained control of loops in python? (or in a perfect world a way to group rows this way with list comprehensions?) Rowspan can be none, meaning 1, and it can be zero. Zero means the row extends from the current cell until the end of the table. That isnt used much, and not in the table I am scraping at all. -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
johnzenger at gmail.com writes: Python lets you iterate through a list using an integer index, too, although if you do so we will make fun of you. You can accomplish it with a while loop, as in: i = 0 while i len(rows): if rows[i] == This code looks like BASIC without the WEND, doesn't it?: ahh, that would work. Yea its really ugly too. I will probably just use the shandy.b's suggestion squirreled away in a method. I shouldnt even care, its just one extra conditional per row -- http://mail.python.org/mailman/listinfo/python-list
Re: Best python module for Oracle, but portable to other RDBMSes
What would be the next best Oracle database module for Python next to cx_oracle? I'd like to compare two and choose one, just for the sake of seeing how two modules doing the same thing operate. Also, does installing cx_oracle create registry entries or require admin privs on a Windows XP machine? I see that cx_oracle is distributed as an EXE. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Best python module for Oracle, but portable to other RDBMSes
Also, what's the difference between something like cx_oracle and an ODBC module? If I were to use an ODBC module (not trying to torture myself here, I promise, but I just want to see what alternatives exist and how they work). -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
Although I don't know if this is faster or more efficient than your current solution, it does look cooler: def grouprows(inrows): rows = [] rows[:] = inrows # makes a copy because we're going to be deleting while len(rows) 0: rowspan = rows[0][rowspan] yield rows[0:rowspan] # returns this value, but control flow unaffected del rows[0:rowspan] # remove what we just returned from the list, and loop grouper = grouprows(copyrows) print [x for x in grouper] This is basically just a simple function that rips chunks off the front of a list and returns them. Because the function uses yield rather than return, it becomes a generator, which can be treated by Python as an iterator. -- http://mail.python.org/mailman/listinfo/python-list
Re: Is Python a Zen language?
On 26 Feb 2006 14:55:04 -0800, Andrea Griffini wrote: IMO another language that would be hard to classify is COBOL ... but for other reasons :-) According to Dijkstra: The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offence. That makes Cobol a Zen language (since it not only changes, but also cripples the mind). And BASIC too: It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration. -- USB Priests for only 10$ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Flash
By the way Sybren, if you don't mind, what kinda computer and browser were you using, trying to figure out which browsers get redirected to html and which get the Flash Site. If you have Flash plugin, what version was it? Thanks, Sam the Gardener -- http://mail.python.org/mailman/listinfo/python-list
Re: minimize a program into an icon on the taskbar.
Rajesh Sathyamoorthy: Hi, I would know how to minimize a program (wxpython app) into an icon on the taskbar on windows (the one at the side near the clock, i can't remember what is it called.) Is it easy to be done? Is there a way to do the same thing on Linux? Did you look into wx.TaskBarIcon? Cheers, Frank -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Flash
SamFeltus wrote: I aint a professional coder, but a gardener. However, the Flash-JSON-Python technique works. It is poorly coded, but it is IMO a very simple way to integrate Flash and Python compared to the methods normally suggested on the net. The HTML is just some junk thrown up for people with lower tech browsers without much thought or consideration. Some people with high-tech browsers don't use Flash for non-technical reason. The audit clauses in the license allow Macromedia to audit your computers for license compliance at any time, so some companies that feel strongly about their data staying away from prying eyes won't allow it to be installed. It's illegal to install Flash on some versions of Windows, let alone more esoteric operating systems. Using the version bundled with IE may skirt some of these issues, I'm not sure. see http://www.macromedia.com/shockwave/download/license/desktop/ especially 2(b) and 3(a). -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Flash
SamFeltus enlightened us with: By the way Sybren, if you don't mind, what kinda computer and browser were you using, trying to figure out which browsers get redirected to html and which get the Flash Site. Mozilla Firefox 1.5, on Ubuntu Linux Breezy. If you have Flash plugin, what version was it? Shockwave Flash 7.0 r25 Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Matplotlib logarithmic scatter plot
Derek == Derek Basch [EMAIL PROTECTED] writes: Derek Great! That worked fine after I played with it for a Derek bit. One last question though. How do I label the ticks Derek with the product of the exponentiation? For instance: Derek 100 Derek instead of Derek 10**2 You can supply your own custom tick formatters (and locators). See http://matplotlib.sf.net/matplotlib.ticker.html and examples http://matplotlib.sourceforge.net/examples/custom_ticker1.py http://matplotlib.sourceforge.net/examples/major_minor_demo1.py http://matplotlib.sourceforge.net/examples/major_minor_demo2.py JDH -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
Ben Finney wrote: PEP 354: Enumerations in Python has been accepted as a draft PEP. The current version can be viewed online: -1 on the proposal as a builtin, -0 on including any kind of enumeration in the standard library unless I can see a compelling use case; Carl Banks' approach seems more flexible and doesn't add yet more to the burgeoning Python distro. Add me to the me, too! list of people who think enumerations would be better off without or comparison. -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
johnzenger at gmail.com writes: Although I don't know if this is faster or more efficient than your current solution, it does look cooler: def grouprows(inrows): rows = [] rows[:] = inrows # makes a copy because we're going to be deleting while len(rows) 0: rowspan = rows[0][rowspan] yield rows[0:rowspan] # returns this value, but control flow unaffected del rows[0:rowspan] # remove what we just returned from the list, and loop grouper = grouprows(copyrows) print [x for x in grouper] wow, i think this is much better then my solution. And you can easily call it for subgroups: grouper = grouprows(rows) for x in grouper grouperTwo = grouprows(x) for y in grouperTwo Do i need to copy the list in the iterator? (if I am not planning on using rows again) The reference count for the list members will get bumped on yield right? -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
On Monday 27 February 2006 02:49, Ben Finney wrote:
Coercing a value from an enumeration to a ``str`` results in the
string that was specified for that value when constructing the
enumeration::
That sentence seems to assume that all enumeration values will have been
specified as strings. Thats reasonable, but your description of the creation
of an enumeration doesnt specify that.
An enumerated type is created from a sequence of arguments to the
type's constructor::
Weekdays = enum('sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat')
Grades = enum('A', 'B', 'C', 'D', 'F')
s/arguments/strings/
?
--
Toby Dickenson
--
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Looking for Pythonic Examples
Hello I am looking for examples of Pythonic Thinking: One example I found: Here some lines of the web side of Bruce Eckel: http://www.mindview.net/WebLog/log-0053 How to read a text file: for line in file(FileName.txt): # Process line It is a easy and sophisticated thing in python, but hard to do or more complicated in other languages like java. Does anyone know more examples ? Does anyone know books about real good python programming ? Best Regards Gerhard -- http://mail.python.org/mailman/listinfo/python-list
escaping quotes
I'm reading through the tutorial and found this in section 3: 'Isn\'t, she said.' 'Isn\'t, she said.' Why doesn't the escape sequence work in this case? -- http://mail.python.org/mailman/listinfo/python-list
RE: MySQLdb compile error with AMD64
Can anyone offer any assistance on this one? Is it unsupported on AMD64 ? Nothing in the README points to that. I thought it would default to 32bit if not supported under 64. Hi, I have been using MySQLdb on a 32-bit processor, no worries. Love it. I went to install on an AMD64 running the 64-bit version of SUSE 10.0. I get the following error during the python setup.py build gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -fmessage-length=0 -Wall -D_FORTIFY_SOURCE=2 -g -fPIC -I/usr/include/mysql -I/usr/include/python2.4 -c _mysql.c -o build/temp.linux-x86_64-2.4/_mysql.o -I/usr/include/mysql -g -march=i586 -mcpu=i686 -fmessage-length=0 `-mcpu=' is deprecated. Use `-mtune=' or '-march=' instead. _mysql.c:1: error: CPU you selected does not support x86-64 instruction set _mysql.c:1: error: CPU you selected does not support x86-64 instruction set error: command 'gcc' failed with exit status 1 Any ideas on what I have to do to make this work? Any help appreciated! Cheers Keith -- http://mail.python.org/mailman/listinfo/python-list
Numerical solver
Hello, I would like to use a numerical solver for a specific problem. My problem looks like this: 1. I have numeric constants, named A,B,C etc. 2. I have numeric variables, named x,y,z etc. 3. I have functions, like f1(x), f2(x), f3(x,y), f4(y) etc. 4. I have constraints like f1(x) A f3(x,y) B etc. Fortunately, all of the variables can be limited to a closed finite interval. (E.g. 0 = x = 100) There is a specific function, called P(x,y,z) that needs to be optimized (need to find its maximum/minimum). I'm looking for a native Python solution: I would like to define the functions and the constraints in Python. I have looked at the cheeseshop and found LogiLab's constraint: http://www.logilab.org/projects/constraint/documentation It is almost perfect for me, but it is working with finite sets. I'm not sure about SciPy or NumPy. Do you have an idea about what is the package I need? I'll gladly read any documentation or tutorial, just I do not know which one is the best to start with. Thanks, Laszlo -- http://mail.python.org/mailman/listinfo/python-list
Re: Best python module for Oracle, but portable to other RDBMSes
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 [EMAIL PROTECTED] wrote: What would be the next best Oracle database module for Python next to cx_oracle? That would probably be DCOracle2. I'd like to compare two and choose one, just for the sake of seeing how two modules doing the same thing operate. Also, does installing cx_oracle create registry entries or require admin privs on a Windows XP machine? I see that cx_oracle is distributed as an EXE. It's most probably created using distutils and python setup.py bdist_wininst. These installers only use the registry to look up the path Python where is installed. Of course it will need a correctly working Oracle client to operate. - -- Gerhard -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEBJxBdIO4ozGCH14RAqXCAJ9Vq6L8SLvnhlBCDc4EzwloJYp28ACfVt8J TNN+XgNxFLmQscu9wpPIK4M= =txAA -END PGP SIGNATURE- -- http://mail.python.org/mailman/listinfo/python-list
Re: escaping quotes
John Salerno wrote: I'm reading through the tutorial and found this in section 3: 'Isn\'t, she said.' 'Isn\'t, she said.' Why doesn't the escape sequence work in this case? because the interactive prompt echos the result back to you as a Python literal, where possible. compare 'Isn\'t, she said.' 'Isn\'t, she said.' with print 'Isn\'t, she said.' Isn't, she said. (this is explained a little later in the chapter you're reading) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Numerical solver
Laszlo Zsolt Nagy wrote: Hello, I would like to use a numerical solver for a specific problem. My problem looks like this: 1. I have numeric constants, named A,B,C etc. 2. I have numeric variables, named x,y,z etc. 3. I have functions, like f1(x), f2(x), f3(x,y), f4(y) etc. 4. I have constraints like f1(x) A f3(x,y) B etc. Fortunately, all of the variables can be limited to a closed finite interval. (E.g. 0 = x = 100) There is a specific function, called P(x,y,z) that needs to be optimized (need to find its maximum/minimum). In [7]: scipy.optimize.fmin_cobyla? Type: function Base Class: type 'function' String Form:function fmin_cobyla at 0x4fff3b0 Namespace: Interactive File: /Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy- 0.4.7.1607-py2.4-macosx-10.4-ppc.egg/scipy/optimize/cobyla.py Definition: scipy.optimize.fmin_cobyla(func, x0, cons, args=(), consargs=None, rhobeg=1.0, rhoen d=0.0001, iprint=1, maxfun=1000) Docstring: Minimize a function using the Contrained Optimization BY Linear Approximation (COBYLA) method Arguments: func -- function to minimize. Called as func(x, *args) x0 -- initial guess to minimum cons -- a sequence of functions that all must be =0 (a single function if only 1 constraint) args -- extra arguments to pass to function consargs -- extra arguments to pass to constraints (default of None means use same extra arguments as those passed to func). Use () for no extra arguments. rhobeg -- reasonable initial changes to the variables rhoend -- final accuracy in the optimization (not precisely guaranteed) iprint -- controls the frequency of output: 0 (no output),1,2,3 maxfun -- maximum number of function evaluations. Returns: x -- the minimum -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
telnetlib problems
I'm trying to use a python script to access an embedded computer
running linux and connected via a crossover ethernet cable using the
following script...
...and I realize the username and password is not realistic... I'm
still in proof of concept stage here :)
#
import telnetlib
tn = telnetlib.Telnet('192.168.100.11')
tn.read_until('login: ', 5)
tn.write('user\n')
tn.read_until('Password: ', 5)
tn.write('password\n')
tn.read_until('bash-2.05$ ', 5)
tn.write('ls\n')
print tn.read_very_eager()
#
As a script, this doesn't work. However, if I execute the same
commands interactively, it works fine. If I insert some time delays as
follows...
#
import telnetlib
import time
tn = telnetlib.Telnet('192.168.100.11')
tn.read_until('login: ', 5)
time.sleep(2)
tn.write('user\n')
tn.read_until('Password: ', 5)
time.sleep(2)
tn.write('password\n')
tn.read_until('bash-2.05$ ', 5)
tn.write('ls\n')
time.sleep(2)
print tn.read_very_eager()
#
...and it works fine. Can anyone tell me what's going on here? TIA
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Re: sort one list using the values from another list
[EMAIL PROTECTED] wrote: Following Ron Adam solution (and using [] instead of list() in the last line), this may be a possible solution of the problem, that is often quite fast: def psort16(s1, s2): try: d = dict(izip(s2, s1)) except TypeError: _indices = range(len(s1)) _indices.sort(key=s2.__getitem__) s1[:] = map(s1.__getitem__, _indices) else: if len(d) == len(s1): s1[:] = [d[v] for v in sorted(d)] else: _indices = range(len(s1)) _indices.sort(key=s2.__getitem__) s1[:] = map(s1.__getitem__, _indices) Bye, bearophile Looks good, but I think It would be simpler to just do. def psort17(s1, s2): try: d = dict(izip(s2, s1)) assert len(d) != len(s2) s1[:] = [d[v] for v in sorted(d)] except Exception: _indices = range(len(s1)) _indices.sort(key=s2.__getitem__) s1[:] = map(s1.__getitem__, _indices) We don't need to specify which exception. Any problems will just get raised again on the second try it also fails. Cheers, Ron -- http://mail.python.org/mailman/listinfo/python-list
Threading - will threads run in parallel?
I have 2 threads that I want to run at the same time: for instance: from threading import Thread class test(Thread): def run(self): while True: get(asdf) class test2(Thread): def run(self): while True: get(jkl) ack=test() jkl=test2() ack.start() jkl.start() (get() is a function which waits for a ping on a specific port, thus stopping the program for a while.) Will these run together, or do I have to find some other way of running in parallel? Also, is it possible to split off a program for the terminal that started it? As in I type in python test.py and test.py runs in the background and lets me do other things in that terminal? -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
Stefan Rank [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] recent examples from this list: 2006-01-03: http://www.nabble.com/Re%3A-Regex-anomaly-p2179421.html 2006-02-20: http://www.nabble.com/Re%3A-Regular-expression-gone-mad-p3029028.html If the re flags were implemented as instances of object instead of int, then misuse of them as int args would be excepted. I don't know if such a change would otherwise cause a problem. I wonder whether a subclass of object (EnumSet?) that allowed for initialization with a better string representation and that disabled order comparisons would fill the bill for unordered enum. As Steven Bethard also noted, there seem to be a need for two Enum subclasses: EnumSet and EnumSeq. Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: telnetlib problems
I just hit upon something that seems to work...
##
import telnetlib
from select import select
tn = telnetlib.Telnet('192.168.100.11')
sock = tn.get_socket()
tn.read_until('login: ', 5)
select([sock], [], [], 5)
tn.write('user\n')
tn.read_until('Password: ', 5)
select([sock], [], [], 5)
tn.write('password\n')
tn.read_until('bash-2.05$ ', 5)
tn.write('ls\n')
select([sock], [], [], 5)
print tn.read_very_eager()
##
If anyone sees any potential problems with this, I would appreciate it.
TIA
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Thread Question
I have a client application that I want (behind the scenes) to check and make sure a remote host is up (i.e. by ping or TCP connect). I'm assuming that, since I want this to go on unknowingly to the user, that I would put this in a thread. My question is, how would I go about creating the thread? I have seen examples that used classes, and other examples that just called one thread start command - when should you use one over another? Thanks in advance. Doug -- http://mail.python.org/mailman/listinfo/python-list
Re: Threading - will threads run in parallel?
Also, is it possible to split off a program for the terminal that started it? As in I type in python test.py and test.py runs in the background and lets me do other things in that terminal? try: python test.py -- http://mail.python.org/mailman/listinfo/python-list
Re: Threading - will threads run in parallel?
SolaFide: (get() is a function which waits for a ping on a specific port, thus stopping the program for a while.) Will these run together, Thread 2 can run while thread 1 is blocked for I/O and v.v. Also, is it possible to split off a program for the terminal that started it? As in I type in python test.py and test.py runs in the background and lets me do other things in that terminal? Platform? Shell? -- René Pijlman -- http://mail.python.org/mailman/listinfo/python-list
Re: Threading - will threads run in parallel?
Thanks! The problem is on Windows: when I run c:\python24\myprogram.py, it has a command window open up. If I close it, the program ends. So I want it to run without opening that window. -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for Pythonic Examples
This one is from our very own BDFL, behold- wget implemented in 7 lines
of python code:
import sys, urllib
def reporthook(*a): print a
for url in sys.argv[1:]:
i = url.rfind('/')
file = url[i+1:]
print url, -, file
urllib.urlretrieve(url, file, reporthook)
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Re: Threading - will threads run in parallel?
SolaFide napisał(a): The problem is on Windows: when I run c:\python24\myprogram.py, it has a command window open up. If I close it, the program ends. So I want it to run without opening that window. Give it .pyw extension or start using pythonw.exe instead of python.exe. -- Jarek Zgoda http://jpa.berlios.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: escaping quotes
Fredrik Lundh wrote: because the interactive prompt echos the result back to you as a Python literal, where possible. compare Ah, of course! I forgot it wasn't 'print'ing it. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: Thread Question
On 2006-02-28, D [EMAIL PROTECTED] wrote: I have a client application that I want (behind the scenes) to check and make sure a remote host is up (i.e. by ping or TCP connect). I'm assuming that, since I want this to go on unknowingly to the user, that I would put this in a thread. Probably. My question is, how would I go about creating the thread? Assuming foo is the function you want to start in a thread: threading.Thread(target=foo).start() I have seen examples that used classes, and other examples that just called one thread start command - when should you use one over another? I'm not sure what you mean by use classes vs. calling a thread start command. My example above uses a class (threading.Thread) to create a thread object, and then calls its start method. -- Grant Edwards grante Yow! HELLO, little boys! at Gimme a MINT TULIP!! Let's visi.comdo the BOSSA NOVA!! -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
You don't need to copy the list; but if you don't, your original list will be emptied. Len(rows) recalculates each time the while loop begins. Now that I think of it, rows != [] is faster than len(rows) 0. By the way, you can also do this using (gasp) a control index: def grouprows(rows): index = 0 while len(rows) index: rowspan = rows[index][rowspan] yield rows[index:rowspan + index] index += rowspan ...which kind of brings us back to where we started. -- http://mail.python.org/mailman/listinfo/python-list
Re: Thread Question
Em Ter, 2006-02-28 às 20:24 +, Grant Edwards escreveu:
I have seen examples that used classes, and other examples
that just called one thread start command - when should you
use one over another?
I'm not sure what you mean by use classes vs. calling a
thread start command. My example above uses a class
(threading.Thread) to create a thread object, and then calls
its start method.
# He meant calling direct vs. subclassing. In your example you called
the Thread class directly, but you could have subclassed it.
# In your case, Edwards, I'd prefer subclassing because then you could
put some states in the class. A (bad) example:
class Foo(Thread):
def __init__(self):
Thread.__init__(self)
self.alive = False
self.running = True
def run(self):
while self.running:
self.alive = ping('myhost')
sleep(10)
def stop(self):
self.running = False
# Then you could:
a = Foo()
do_something()
print a.alive
do_something_more()
print a.alive
finish_everything()
print a.alive
a.stop()
# quit
--
Quem excele em empregar a força militar subjulga os exércitos dos
outros povos sem travar batalha, toma cidades fortificadas dos outros
povos sem as atacar e destrói os estados dos outros povos sem lutas
prolongadas. Deve lutar sob o Céu com o propósito primordial da
'preservação'. Desse modo suas armas não se embotarão, e os ganhos
poderão ser preservados. Essa é a estratégia para planejar ofensivas.
-- Sun Tzu, em A arte da guerra
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Re: Thread Question
Thanks, Grant. I apologize for not being clear on what I meant by using classes. This is an example of what I was referring to: http://www.wellho.net/solutions/python-python-threads-a-first-example.html See the second (threaded) example. Doug -- http://mail.python.org/mailman/listinfo/python-list
Make staticmethod objects callable?
Hi everyone, I was wondering if it would make sense to make staticmethod objects callable, so that the following code would work: class A: @staticmethod def foo(): pass bar = foo() I understand staticmethod objects don't need to implement __call__ for their other use cases, but would it still make sense to implement __call__ for that specific use case? Would it be error-prone in any way? Thx and regards, Nicolas -- http://mail.python.org/mailman/listinfo/python-list
Re: Firebird and Python
All the info you need is in the kinterbasdb module. I've worked with it under windows and Linux and... it just works. Really well indeed. I'd recommend it a lot. http://kinterbasdb.sourceforge.net/dist_docs/usage.html#faq_fep_embedded_using_with -- Asier. -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
Em Ter, 2006-02-28 às 09:10 -0800, [EMAIL PROTECTED] escreveu: Although I don't know if this is faster or more efficient than your current solution, it does look cooler: [snip] print [x for x in grouper] This is not cool. Do print list(grouper) -- Quem excele em empregar a força militar subjulga os exércitos dos outros povos sem travar batalha, toma cidades fortificadas dos outros povos sem as atacar e destrói os estados dos outros povos sem lutas prolongadas. Deve lutar sob o Céu com o propósito primordial da 'preservação'. Desse modo suas armas não se embotarão, e os ganhos poderão ser preservados. Essa é a estratégia para planejar ofensivas. -- Sun Tzu, em A arte da guerra -- http://mail.python.org/mailman/listinfo/python-list
Re: Thread Question
On 2006-02-28, D [EMAIL PROTECTED] wrote: Thanks, Grant. I apologize for not being clear on what I meant by using classes. This is an example of what I was referring to: http://www.wellho.net/solutions/python-python-threads-a-first-example.html Ah, I see. I had forgotten that people subclass Thread like that. It's mostly just a matter of style. There aren't any practical differences that I can think of. -- Grant Edwards grante Yow! BARBARA STANWYCK at makes me nervous!! visi.com -- http://mail.python.org/mailman/listinfo/python-list
Re: comple list slices
[EMAIL PROTECTED]: Len(rows) recalculates each time the while loop begins. Now that I think of it, rows != [] is faster than len(rows) 0. the difference is very small, and len(rows) is faster than rows != [] (the latter creates a new list for each test). and as usual, using the correct Python spelling (rows) is a lot faster (about three times in 2.4, according to timeit). /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Thread Question
Em Ter, 2006-02-28 às 20:38 +, Grant Edwards escreveu: On 2006-02-28, D [EMAIL PROTECTED] wrote: Thanks, Grant. I apologize for not being clear on what I meant by using classes. This is an example of what I was referring to: http://www.wellho.net/solutions/python-python-threads-a-first-example.html Ah, I see. I had forgotten that people subclass Thread like that. It's mostly just a matter of style. There aren't any practical differences that I can think of. Within a class you can maintain lots of internal states and make it easily changable by other threads. Sure, you could archive this with functions, but IMHO it's not pythonic. But for simple cases both would suffice. -- Quem excele em empregar a força militar subjulga os exércitos dos outros povos sem travar batalha, toma cidades fortificadas dos outros povos sem as atacar e destrói os estados dos outros povos sem lutas prolongadas. Deve lutar sob o Céu com o propósito primordial da 'preservação'. Desse modo suas armas não se embotarão, e os ganhos poderão ser preservados. Essa é a estratégia para planejar ofensivas. -- Sun Tzu, em A arte da guerra -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 354: Enumerations in Python
On Tue, 28 Feb 2006 14:26:49 -0500 Terry Reedy [EMAIL PROTECTED] wrote: Stefan Rank [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] recent examples from this list: 2006-01-03: http://www.nabble.com/Re%3A-Regex-anomaly-p2179421.html 2006-02-20: http://www.nabble.com/Re%3A-Regular-expression-gone-mad-p3029028.html If the re flags were implemented as instances of object instead of int, then misuse of them as int args would be excepted. I don't know if such a change would otherwise cause a problem. I wonder whether a subclass of object (EnumSet?) that allowed for initialization with a better string representation and that disabled order comparisons would fill the bill for unordered enum. As Steven Bethard also noted, there seem to be a need for two Enum subclasses: EnumSet and EnumSeq. And one other distinction -- mutable versus immutable. A immutable enum is the usual use case, a mutable one is a vocabulary (i.e. an open set of symbols, which nevertheless requires controlled access). The key thing about symbols like enums etc is that they don't really represent anything (or that which they represent is inconvenient to bind to the symbols -- perhaps its even an abstract concept that has no programmatic representation beyond the enumerated value). One thing about an enumerated value is that it should know what enum it belongs to. For example, I'm currently working on a project that has the following rather unfortunate near-collision of symbols: sym.ABSTRACTS scope of abstract nouns in SCOPE vocabulary sym.ABSTR definiteness of abstract noun in ARTICLE enum sym.ABST number of noun which has no count because abstract (not mass) NUMBER enum It's quite useful that I can ask sym.ABST which one of the above domains it's in: sym.ABST.domain NUMBER or even better: sym.ABST !NUMBER: ABST Which makes the enumeration values somewhat self-documenting. I'm currently trying to figure out how best to make this instead show (e.g.): sym.ABST !NUMBER: ABST - Noun uncountable because abstract. I can of course, also use this to catch errors by checking that the pluralization function in my locale module has been passed a NUMBER or an explicit int, instead of say, a SCOPE, by accident. Another feature here is that all of these symbols, though also defined within their domain collections is also made into an attribute of the sym object (which is a trivial class or convenience namespace). I also raise an error if any domain tries to overwrite a symbol in sym, so I can avoid accidental collisions. I'm still tinkering with this, and the above is from memory, but I do have it working on another machine. I'm currently subclassing from dict, not set, though I'm unsure if this is really wise (but I'm more familiar with dict, and I'm currently making use of the mapping internally, though I'm not sure I really need to). I'm not sure this would be a smart way to do this in another application, but it looks promising for this one (which is a kind of artificial locale-neutral language representation). I'm not sure that the enum described in the PEP would be as useful to me as this. So I'm -0 on it becoming a built-in, though I'm +0 on it becoming a module (it's not that hard to type from enum import Enum). But I'm not sure it's the best enum, or even that one size fits all with enums (though having fewer implementations might improve clarity if they are really equivalent). Cheers, Terry -- Terry Hancock ([EMAIL PROTECTED]) Anansi Spaceworks http://www.AnansiSpaceworks.com -- http://mail.python.org/mailman/listinfo/python-list
Long running Script stops responding, CPU usage increases
Title: Long running Script stops responding, CPU usage increases This is running Python 2.3 on windows 2003/windows xp. I have written a script to display and filter the Win32 event log in a scrolling list to the command line (it also does some summary tasks). It uses the win32evtlog.ReadEventLog to seek or scan the event log based on filter parameters. It is supposed to run until the user kills it, so there are repeated calls to ReadEventLog. The problem is that after the script has run from some time (usually several hours), the call to ReadEventLog seems to hang and the CPU usage increases dramatically (from nil to 30-50%). The script does not exit this stage, and has to be broken manually with Ctrl-C. I've tried closing and reopening the event log handle after it has been open for an hour. I've added explicit calls to the garbage collector. Neither helped at all. I realize that this is an API call, so it may not be a python issue. But I have seen this type of behavior on other scripts (not event loggers), but they were test/debug tools and weren't important enough to track down the issue. Any help would be appreciated. code example: def OpenLog( self ): # #open event log # self.mHandle = win32evtlog.OpenEventLog( self.mComputer , self.mLogType ) if not self.mHandle: raise ValueError, invalid handle self.mLogOpenTmst = time.time() def CloseLog( self ): win32evtlog.CloseEventLog( self.mHandle ) def ReadLog( self ): self.mFlags = win32evtlog.EVENTLOG_FORWARDS_READ|win32evtlog.EVENTLOG_SEEK_READ vEventScon = win32evtlog.ReadEventLog( self.mHandle , self.mFlags , self.mLogOffset ) # # if not found, try again in 5 seconds # if not vEventScon: # # If we've had the log open for more than 1 hour, dump it and reopen # if ( time.time() (self.mLogOpenTmst + 3600) ): self.CloseLog() self.OpenLog() time.sleep( 5 ) return bOk # # snip... # manipulate event records here # # # main # OpenLog Ok = 1 while Ok: Ok = ReadLog() CloseLog() -- http://mail.python.org/mailman/listinfo/python-list
