Re: Printer List from CUPS
Mike Tammerman wrote: > Hi, > > I want to get the printer list from CUPS. I found some ways using > > lpstat -p and > http://localhost:631/printers > > but, these ways require some parsing and I am not sure, if the parsing > works all the time. A pythonic way would be very helpful. > > Thanks, > Mike > The HPLIP project (hpinkjet.sf.net) includes a basic CUPS extension module in the src/prnt/cupsext directory. Its pretty rough, but it will return a list of CUPS printers easily enough. I am in the process of rewriting it in Pyrex and hope to include more complete CUPS API coverage. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new instance of Python class in C
Sybren Stuvel wrote: > Hi people, > > I'm creating a program that can solve and create Sudoku puzzles. My > creation function needs to make a lot of copies of a puzzle. Until > now, I used copy.deepcopy(), but that's too slow. I want to implement > such a copying function in C and use that instead. My idea about this > is: > > - Get the data from a puzzle (a list containing lists containing > strings) and make a copy of it. That's coded already. > > - Create a new SodokuPuzzle instance and assign the data to it. > > That last step can be done by passing the data to the constructor, so > that's easy too once I know how to do that in C. My question is: how > do I create a new instance in C of a class written in Python? I've > searched Google, but found nothing of help. > > Sybren Personally, I would try Psyco first, and consider Pyrex next. Are you sure your algorithm can't be optimized first, before you start trying to write this in C? -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do Pythoneers reinvent the wheel?
Stefano Masini wrote: > I don't know what's the ultimate problem, but I think there are 3 main > reasons: > 1) poor communication inside the community (mhm... arguable) > 2) lack of a rich standard library (I heard this more than once) > 3) python is such an easy language that the "I'll do it myself" evil > side lying hidden inside each one of us comes up a little too often, > and prevents from spending more time on research of what's available. > I think, for me, this most important reason is that the stdlib version of a module doesn't always completely fill the requirements of the project being worked on. That's certainly why I wrote my own, much simpler, logging module. In this case, its obvious that the original author of the stdlib logging module had different ideas about how straightforward and simple a logging module should be. To me, this just demonstrates how difficult it is to write good library code - it has to try and be everything to everybody without becoming overly general, abstract, or bloated. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: PyQt documentation
Eric Jardim wrote: Hi, Is there any site that gather all the documentation about PyQt? The docs of the Riverbank site is poor, and I have found separate tutorials on the net. I know that the Kompany have made a "Qtdoc"-like to PyQt. But it is not free doc. Does anybody know anything about any project for making PyQt development more easy? thanks, [Eric Jardim] If you follow a few simple rules, you can use the C++ Qt docs as-is: 1. Replace ::'s with .'s 2. Replace ->'s with .'s 3. Access to things like .text member variables have to be done with .text() 4. .exec() becomes .exec_loop() 5. Follow the PyQt instructions on how to do signals and slots with connect() 6. Convert QStrings with str() from Qt functions/methods if you want to work with them with std. Python string functions I'm sure there's a few more, but those are the main ones. Its actually very easy to convert in your head as you go to the proper Pythonic usage of Qt. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Like overloading __init__(), but how?
This was discussed only days ago: http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/41a6c0e1e260cd72/fc1c924746532316?q=multiple+constructors+python&_done=%2Fgroups%3Fq%3Dmultiple+constructors+python%26&_doneTitle=Back+to+Search&&d#fc1c924746532316 -Don John M. Gabriele wrote: I know that Python doesn't do method overloading like C++ and Java do, but how am I supposed to do something like this: - incorrect #!/usr/bin/python class Point3d: pass class Vector3d: """A vector in three-dimensional cartesian space.""" def __init__( self ): """Create a Vector3d with some reasonable default value.""" x, y, z = 0.0, 0.0, 0.0 def __init__( self, x_from, y_from, z_from, x_to, y_to, z_to ): """Create a Vector3d from x-y-z coords.""" # ... pass def __init__( self, point_from, point_to ): """Create a Vector3d from two Point3d objects.""" # ... pass def __init__( self, same_as_this_vec ): """Create a Vector3d from a copy of another one.""" # ... pass p = Point3d() p2 = Point3d() # v = Vector3d( p2, p ) -- Nope. Only the last __init__() counts. -- /incorrect --- Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Exception handling code (try/except/finally)
c.l.p- I am having trouble understanding how one is supposed to correctly utilize try:...except:...finally: in real code. If I have a block of code like: def foo(): try: ... some code that can raise an exception ... finally: ... do some cleanup ... return something If any exception occurs in the code inside the try:...finally:, it will fail silently, which is a bad thing. So, the obvious thing to do (I think) is: def foo(): try: try: ... some code that can raise an exception ... except someerror: ... handle the error... finally: ... do some cleanup ... return something But, now the finally doesn't really serve any purpose, if all the exceptions are handled by except:, finally will never be called as a result of an exception, only as the last statements of the function. So, the next step is to do this? def foo(): try: try: ... some code that can raise an exception ... except someerror: ... handle the error... raise someerror finally: ... do some cleanup ... return something Which, I guess will work, but it feels very awkward. Is this the preferred/"correct" way to handle this? Is there a more elegant solution? Also, why is this construct not possible?: try: ... some code that can raise an exception ... except someerror: ... handle the error... finally: ... do cleanup, etc. ... Thanks, Don -- http://mail.python.org/mailman/listinfo/python-list
PyZeroConf Question
AMK, thanks for your work on PyZeroConf! Using PyZeroConf 0.12. I'm seeing an issue with the Browser.py code. I am scanning for printers using: type = "_pdl-datastream._tcp.local." The list of printers is returned, but every call to getServiceInfo() in the Listener objectresults in a timeout and None being returned. I am not trying to publish any services, just discovery. Also, at the end of the list, the code seems to hang. Any ideas? Thanks, Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Is Python good for graphics?
Esmail Bonakdarian wrote: First of all, I *really* like Python ;-) I need some help with the graphical side of things. I would like to do some basic graphics with Python, but I am not sure what the best/most effective way for me to do what I want. Basically, I would like to be able to create some basic animations where I can help visualize various sorting algorithms (for instance http://ciips.ee.uwa.edu.au/~morris/Year2/PLDS210/sorting.html#insert_anim) or graph searches (coloring nodes as each gets visited). (Something like this: http://cs.smith.edu/~thiebaut/java/graph/Welcome.html) Or to create and manipulate programmatically a simple 2-D block puzzle (like this: http://www.johnrausch.com/SlidingBlockPuzzles/quzzle.htm). Note, the ability to do this via the web would be nice, but definitely is *not* required at the moment. These would be used to help in learning/teaching. I am aware of Tkinter and wxPython (by aware I mean I know of their existence :-) Before investing (a lot?) of time to learn these, I thought I’d ask the more experienced folks around here what would be the best way to invest my time to get basic graphics going. I really am not concerned so much with efficiency as easy of use. Can anyone recommend what would suit my rather limited needs best? Are there other graphics libraries I should consider that would be more suitable? Or is Python not the way to go for this? Thanks! Esmail PyGame? http://www.pygame.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: what would you like to see in a 2nd edition Nutshell?
I found the discussion of unicode, in any python book I have, insufficient. Thomas +1 Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's use in RAD
Ross Cowie wrote: Hi, I am currenly a second year university student and was wondering if you could help me ut. As part of a project i have decided to write about python, i am not having very much luck with regards to finding infrmation on pythons use in Rapid Application Development, and was wondering of you could highlight some of the features that make it suitable for RAD. Like the use of dinamic binding. Your healp would be appreciated. Hope to hear from you soon. Ross I got plenty of info in < 1 min using Google and the query "python rad". Does your university not have access to Google? http://www.ukuug.org/events/linux2001/papers/html/CEgli/Gnome-Talk.html http://www.iol.ie/~padraiga/talks/pygtk/ http://www.linuxjournal.com/article/7421 http://pythonnotes.blogspot.com/2005/03/rad-style-programming-for-web-apps.html http://www.pythonology.com/success&story=philips http://librenix.com/?inode=3701 http://linuxgazette.net/issue78/krishnakumar.html http://www.pycs.net/lateral/stories/16.html http://dot.kde.org/1073680602/ etc...etc...etc... -- http://mail.python.org/mailman/listinfo/python-list
Re: Refactoring in Python.
Skip Montanaro wrote: Peter> I am trying to write Master Thesis on refactoring Python code. Peter> Where should I look for information? I'm not sure, but one piece of code to check out would probably be Bicycle Repair Man, a early-stage prototype refactoring tool for Python. I don't recall where it's hosted. Google will know. Skip If you install Eric3, its included. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular Expressions - Python vs Perl
Thomas Bartkus wrote: "codecraig" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] Well so far from what I have found, Perl is faster than Python for RegEx, although perl is harder to read. Yawn How about Python being easier to *write*? It never ceases to amaze me. It takes days, weeks, months, sometimes even years to write significantly useful software. And yet so many seem to think it is worthy to bother over the seconds that might be saved at execution time. If one were to achieve a mere percentage point or two in improving the "write" efficiency of software - think how much more the world gains in software quality and quantity. How about man hours saved? Why does anyone still waste so much angst over execution speed? I doubt the total execution time for all the RegEx queries you ever ran took as much time as you just wasted on your little experiment. Thomas Bartkus While I agree with (most of) your points, one should not overlook the fact that there are cases when performance does matter (huge datasets maybe?). Since the OP didn't indicate why performance was important to him/her, one cannot assume that its not a valid concern. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Which IDE is recommended?
monkey wrote: Read through python site for programming tool, really plenty of choices :-) (For c++, I just can't breath with very very limited choices) Tried Spe, it come with wxGlade built-in very nice(is Spe still actively develop?). But seem that Boa Constructor and PyDev(the plug-in for Eclipse) also worth looking. Actually which one are you guys using? and why? I think it is also valuable for those who are new to python as me. Eric3 for big stuff. SciTE for small stuff. -- http://mail.python.org/mailman/listinfo/python-list
Re: Comparision of GUI framworks
Florian Lindner wrote: > Hello, > I've read the chapter in the Python documentation, but I'm interested in a a > more in-depth comparision. Especially regarding how pythonic it is and how > well it performs and looks under Windows. > I've some C++ experiences with Qt, so I'm very interested to have PyQt > compared to wxWindows and Tk. How fast does PyQt catches up with the > versiones released from Trolltech? etc.. > > Thx, > Florian I would ask this question on the pyqt/pykde mailing list... but, for what's its worth, I've been using PyQt (on Linux) for > 4 years, and am very happy with it. I find it very "Pythonic". When I first started looking at UI toolkits, the decision came down to wx vs. Qt. I found wx a bit more complex and cryptic and less OO than Qt. Also, I find Qt Designer + Eric to be a nicer development environment than Boa Constructor. The main problem with Qt is apparently licensing issues on Windows... I can't comment since I only use PyQt/Qt on Linux. -Don -- http://mail.python.org/mailman/listinfo/python-list
Re: Calling a python function from C++
[EMAIL PROTECTED] wrote: > Let's say I have a python function do some math like the following: > > def doMath(self): >self.val = self.val + 1 > > > How can I call this python function from C++? Assuming I have some sort > of Python wrapper around my C++ codes. > Elmer? http://elmer.sourceforge.net/ -- http://mail.python.org/mailman/listinfo/python-list
Re: pyvm -- faster python
Paul Rubin wrote: > Stelios Xanthakis <[EMAIL PROTECTED]> writes: > >>- The demo is an x86/linux binary only. You shouldn't trust binaries, >> run it in a chrooted environment not as root! > > > Are you going to release the source? If not, it's a lot less interesting. From the website: "...the source will be released when it becomes more complete and stable." -- http://mail.python.org/mailman/listinfo/python-list
