Guppy-PE: A Python Programming Environment
I would like to announce Guppy-PE 0.1 The first version of Guppy-PE, a programming environment providing object and heap memory sizing and analysis and comes with a prototypical specification language that can be used to formally specify aspects of Python programs and generate tests and documentation from a common source. License: MIT For more information, see: http://guppy-pe.sourceforge.net Best Regards, Sverker Nilsson [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: ftplib question - ftp.dir() returns something and ftp.nlst() does not
add ftp.set_debuglevel(3) so you can see what the goes on the wire (without that information, it's hard to tell if it's a bug in the library or a glitch in your server). /F Hello Fredrik , thank you for your reply. I did a ftp.set_debuglevel(3) and ftp.nlst() now prints: ftp.nlst() *cmd* 'TYPE A' *put* 'TYPE A\r\n' *get* '200 Type set to I.\r\n' *resp* '200 Type set to I.' *cmd* 'PORT 10,30,1,31,128,129' *put* 'PORT 10,30,1,31,128,129\r\n' *get* '200 PORT command Ok.\r\n' *resp* '200 PORT command Ok.' *cmd* 'NLST' *put* 'NLST\r\n' *get* '150 About to open data connection.\r\n' *resp* '150 About to open data connection.' *retr* '' *get* '226 Transfer complete.\r\n' *resp* '226 Transfer complete.' [] Nico -- http://mail.python.org/mailman/listinfo/python-list
Re: defining the behavior of zip(it, it) (WAS: Converting a flatlist...)
Steve Holden wrote: Now, see, that's the thing. The more ways there are to write the same program, the harder any given program will be to understand. This is indeed a fairly deliberate approach in the Python world, and contrasts with languages where readability is low because of the multiple different ways of expressing the same idea. you can express ideas in many ways in Python (just witness all the web frameworks and xml toolkits ;-). the deliberate approach you're referring to is more about using a consistent spelling. seriously, if anyone has a job so boring that his only way to express his creativity is to be able call a trivial library operation in many different ways somewhere deep inside his program, his problems are a lot more fundamental than the choice of programming language. (in a way, this is related to what creative programmers sometimes refer to as python's pencil-like qualities; the fact that once you've grokked python's way to do things, the language pretty much disappears from sight. *your* ideas is what matters. see e.g. the venners interview with bruce eckel: http://www.artima.com/intv/aboutme.html http://www.artima.com/intv/prodperf.html http://www.artima.com/intv/typing.html http://www.artima.com/intv/tipping.html for more on this. here's the keynote they're referring to, btw: http://www.mindview.net/FAQ/FAQ-012 /F -- http://mail.python.org/mailman/listinfo/python-list
Re: defining the behavior of zip(it, it) (WAS: Converting a flat list...)
Magnus Lycka wrote: [EMAIL PROTECTED] wrote: Oh, find a need to shut other up ? Oh, find a need to get the last word? /Magnus P.S. Yes, this *is* a test. Looks like you hooked him, Magnus ;-) -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Why is dictionary.keys() a list and not a set?
Duncan Booth wrote:
[EMAIL PROTECTED] wrote:
As for the (k,v) vs (v,k), I still don't think it is a good example. I
can always use index to access the tuple elements and most other
functions expect the first element to be the key. For example :
a=d.items()
do something about a
b = dict(a)
But using the imaginary example :
a = zip(d.values(), d.keys())
do something about a
b = dict(a) # probably not what I want.
The typical use case for the (v,k) tuple would be when you want sort the
contents of a dictionary by value. e.g. counting the number of occurrences
of each word in a document.
a = zip(d.values(), d.keys())
a.sort()
a.reverse()
print Today's top 10:
print str.join(',', [ k for (v,k) in a[:10]])
Ok, so today you can do that another way, but before there was a key
parameter to sort you had to build the tuple somehow:
print str.join(',', sorted(a.iterkeys(),
key=a.__getitem__, reverse=True)[:10])
and the advantage of the latter is of course that it works even when you've
been counting the number of occurences of complex numbers in a document :)
Thanks, so for newer python(2.3+?, don't know when the sort has been
enhanced), this (v,k) is again there for historical reason but not a
real use case any more.
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Re: Why are there no ordered dictionaries?
Christoph Zwerschke wrote: Fuzzyman schrieb: d.keys() will still return a copy of the list, so d.keys()[i] will still be slower than d.sequence[i] Right, I forgot that. Bengt suggested to implement __call__ as well as __getitem__ and __setitem__ for keys, values and items. In this case, you could very effectively access it as d.values[i]. That means making keys, values, and items custom objects. Creating a new instance would have the overhead of creating 4 new objects instead of just 1. Is the added convenience worth it ? (Plus the extra layers of method calls for each access). I'm not sure. It's a nice idea in terms of using it (we could just leave the sequence attribute as an alias for the new keys attribute - for backwards compatibility). All the best, Fuzzyman http://www.voidspace.org.uk/python/index.shtml -- Christoph -- http://mail.python.org/mailman/listinfo/python-list
Re: Draw a triangle...
The Eternal Squire wrote: PyGame is your best bet for pure graphics. Simple shapes can be done in just a few statements. the same applies to Tkinter, of course. from Tkinter import * # set things up c = Canvas(); c.pack() # draw stuff c.create_polygon((0, 100, 50, 0, 100, 100), fill=red) # get things going mainloop() at the draw a triangle level, the main difference is mostly that Tkinter is a bit more likely to be installed on your machine... /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Op 2005-11-24, Mike Meyer schreef [EMAIL PROTECTED]: Antoon Pardon [EMAIL PROTECTED] writes: The usual response is That's not the Python way. That's not calling someone dumb, just pointing out that they don't yet fully understand the Python way. That is not the Python way, is just saying Python doesn't have it in other words. So it can't be the answer to why python can't have something. No, it isn't. At least, it isn't when I use it. A language is more than just an accumulation of features. Well, a good language is more than just an accumulation of features - there's a philosophy underlying the language, that guides what features are added and what features aren't. Other languages have other philosophies, and wind up being good for other things. But how this philosophy influences design is not straight forward. The ternary operator was thought of to go against the philosopy, and now seems to be at least compatible with the philosophy. So when someone asks why it is not in python, saying It is not the python way still doesn't answer the question, because the person would probably still like to know what in his proposal is against the python philosophy and why. When I say That's not the Python way, I mean that such a feature runs counter to my vision of Python's underlying philosophy. Fine, but it would help if you could support this with arguments or at least give an explanation of why you think this is so. My vision isn't perfect - I've changed my mind about things: I used to want real macros, and I initially disliked list comprehensions. My vision doesn't agree with the developers - notably including Guido's - a lot of the time. On the other hand, they haven't done anything that strikes me as so wrong that I want to spend the time required working on Python rather than in Python to allow me to get it fixed. I see nothing wrong with that. But I would apreciate it, should you be more open about something being your personal vision. To me something like: That is not the python way comes accross as: You just don't understand about python, if you ask/propose something like that It gives me the feeling the person is saying something like: Python is like this, I like it this way, so nobody better suggests this changes. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: defining the behavior of zip(it, it) (WAS: Converting a flat list...)
Steve Holden wrote: Magnus Lycka wrote: [EMAIL PROTECTED] wrote: Oh, find a need to shut other up ? Oh, find a need to get the last word? /Magnus P.S. Yes, this *is* a test. Looks like you hooked him, Magnus ;-) and he is permenantly hooked -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Le ruego me perdone.
replace('haber', random.choice('tener', 'hacer', 'lograr'))
Mi espanol es peor que mi python.
-- Christoph
--
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Re: return in loop for ?
Steven D'Aprano wrote: On Thu, 24 Nov 2005 12:51:34 +, Duncan Booth wrote: Steven D'Aprano wrote: While outwardly they apear to offer a technique for making software more reliable there are two shortcomings I'm leery of. First, no verification program can verify itself; That's not a problem if there exists a verification program A which can't verify itself but can verify program B, which in turn also can't verify itself but will verify program A. That is logically equivalent to the first case, so it doesn't get you anywhere. (Just combine A and B into a single program which invokes A unless the input is A when it invokes B instead.) Then there you go, there is a single program which can verify itself. I think you are confabulating the impossibility of any program which can verify ALL programs (including itself) with the impossibility of a program verifying itself. Programs which operate on their own source code do not violate the Halting Problem. Neither do programs which verify some subset of the set of all possibly programs. There seems to have been some misattribution in recent messages, since I believe it was *me* who raised doubts about a program verifying itself. This has nothing to do with the Halting Problem at all. A very simple possible verification program is one that outputs True for any input. This will also verify itself. Unfortunately its output will be invalid in that and many other cases. I maintain that we cannot rely on any program's assertions about its own formal correctness. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: ftplib question - ftp.dir() returns something and ftp.nlst() does not
Nico Grubert wrote: *cmd* 'NLST' *put* 'NLST\r\n' *get* '150 About to open data connection.\r\n' *resp* '150 About to open data connection.' *retr* '' *get* '226 Transfer complete.\r\n' *resp* '226 Transfer complete.' [] it's not obvious how Python could translate '' to anything other than an empty list, so it sure looks like a server issue. (or is a problem with running in passive mode? can you test with- out using passive mode on the same server?) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Op 2005-11-24, Mike Meyer schreef [EMAIL PROTECTED]: [EMAIL PROTECTED] writes: Mike Meyer [EMAIL PROTECTED] writes: [EMAIL PROTECTED] writes: Different programming styles are appropriate for different tasks, different times and different places, different people. And like morality, government, or economics, I do not believe that one style of programming fits all situations. If I read you right, what you're saying is that hammmers aren't good at driving screws. I don't think anyone would argue about that. No, the analogy is more like this. Python is hammer that comes in green or blue. The hammer's developers say (perhaps with some reason) that cool colors like green and blue are the best colors because they promote calm when used. Calm hammerers are more productive and less violent. My work is repairing the inside of dark water tanks. It is hard to see blue and green hammers, and to find them if I put them down. I suggest that Python have the option of red hammers. So you're suggesting a fundamental change to the nature of Python. It's inherently a blue/green language. Making it available in Red violates the spirit and philosphy of the language, which is why: Well this is, is one thing I have a problem with. The python people seem to be more concerned with fighting things that could be used counter the python philosophy, than search for things that enable working in the python philosophy. Why did it take so long before a ternary operator was introduced? Because it was thought it could be too easily abused. The fact that there was also good use for a ternary operator within the spirit of Python was regarded as less important. The Python people respond with horror, pointing out the problems with red hammers. In other words, there are reasons that python doesn't come in red, and they will gladly tell you what they are. Regarding the differences between hammers and screwdrivers... When a screwdriver is appropriate I use a screwdriver. If I need to write code that does a large amount of CPU intensive number crunching, I use C, not Python. Yes. And if you need a red hammmer, you should get a red hammer, not use red spray paint on one that wasn't designed to be red. Just because *you* don't see how providing a red option violates the philosophy of python doesn't mean that it doesn't do so. Well this seems to be the main conflict between those who would like Python to go a bit further and those that oppose it. Should the priority be to enable python's philosophy or should it be the priority to limit python to only allow it's philosophy. One groups seems to think that python's spirit is not broken by allowing things that seem counter to it, as long as people can without much trouble, work within that spirit. An other group seems to think that any allowance to disgress from python's spirit is an assault on it. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Op 2005-11-24, Delaney, Timothy (Tim) schreef [EMAIL PROTECTED]: And this is the crux of it - the majority of such proposals come from people who apparently haven't actually used python that much, and are trying to impose things from other languages onto it. There's nothing wrong with bringing concepts across from other languages (look at the generators history), but you need to understand how it will fit with python before proposing it as a new feature. Why? To propose generators in Python (before they were present) would seem to me a valuable suggestion even if the proposer didn't understand how it will fit. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Sure - that was just an example of mutating the keys list without having direct access to it. If keys was implemented as an object (with a ``__call__`` method) then we could also implement sequence methods on it - making it easier to mutate the keys/values/items directly. All the best, Fuzzyman http://www.voidspace.org.uk/python/index.shtml -- http://mail.python.org/mailman/listinfo/python-list
problem compiling executable with py2exe
I wrote this very simple program that checks a directory and makes a
list of files that surpass a given size.
I tried to compile it using py2exe.
I used py2exe before with more complex programs without any problem.
Now, although my program works fine when I run it from PythonWin, it
won't compile to an executable.
here's the program:
#
import os
blacklist=[]
d=raw_input('path')
s=int(raw_input('maxsize (in bytes):'))
f = os.listdir(d)
outfile = open(d + r'\filelist_for_this_location.txt', 'wb')
outfile.write('files found in ' + d + '\n'+ 'checking maximum filesize:
' + str(s) + ' bytes...\n')
for n in f:
filepath = os.path.join(d,n)
if os.path.isfile(filepath):
outfile.write(n + '\n')
currsize = int(os.path.getsize(filepath))
if currsize = s:
outfile.write(' is too big\n')
blacklist.append(filepath)
outfile.write('\n'+'\n'+ 'blacklist\n')
for bl in blacklist:
outfile.write(bl + '\n')
outfile.close()
##
here's the py2exe error log:
Traceback (most recent call last):
File filesizechecker.py, line 4, in ?
EOFError: EOF when reading a line
any idea?
Tim
--
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Re: Guification of console app
metiu wrote: Say I have a console app that does something in three steps: - opens a file - transfers the file through a serial port - does some elaborations and I want to build a GUI around it that, for example, sets the file name to open or starts the different steps. I started using wxPython (actually boa-constructor) to build a frame with everything I want. The problem is: when the console app method is working, the GUI is locked... How can the console app communicate with the GUI in order to make it tick (think of status messages, progress bars, log messages...)? If I use threads and events, or wxYield, or EVT_IDLE, I'm tweaking the console app so that it won't work just in console anymore. How do you do that? Thanks! I've achieved this in the past by having the GUI trigger the console app in a separate thread and then use a Queue.Queue to send output from the console app to the GUI. As long as the GUI portion is careful never to block on an empty Queue this can work quite well. There's also a cookbook recipe by Jacob Hallen that shows you how to keep a Tkinter GUI running with parallel worker threads. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Antoon Pardon wrote: Op 2005-11-24, Mike Meyer schreef [EMAIL PROTECTED]: [EMAIL PROTECTED] writes: Mike Meyer [EMAIL PROTECTED] writes: [EMAIL PROTECTED] writes: Different programming styles are appropriate for different tasks, different times and different places, different people. And like morality, government, or economics, I do not believe that one style of programming fits all situations. If I read you right, what you're saying is that hammmers aren't good at driving screws. I don't think anyone would argue about that. No, the analogy is more like this. Python is hammer that comes in green or blue. The hammer's developers say (perhaps with some reason) that cool colors like green and blue are the best colors because they promote calm when used. Calm hammerers are more productive and less violent. My work is repairing the inside of dark water tanks. It is hard to see blue and green hammers, and to find them if I put them down. I suggest that Python have the option of red hammers. So you're suggesting a fundamental change to the nature of Python. It's inherently a blue/green language. Making it available in Red violates the spirit and philosphy of the language, which is why: Well this is, is one thing I have a problem with. The python people seem to be more concerned with fighting things that could be used counter the python philosophy, than search for things that enable working in the python philosophy. Why did it take so long before a ternary operator was introduced? Because it was thought it could be too easily abused. The fact that there was also good use for a ternary operator within the spirit of Python was regarded as less important. The Python people respond with horror, pointing out the problems with red hammers. In other words, there are reasons that python doesn't come in red, and they will gladly tell you what they are. Regarding the differences between hammers and screwdrivers... When a screwdriver is appropriate I use a screwdriver. If I need to write code that does a large amount of CPU intensive number crunching, I use C, not Python. Yes. And if you need a red hammmer, you should get a red hammer, not use red spray paint on one that wasn't designed to be red. Just because *you* don't see how providing a red option violates the philosophy of python doesn't mean that it doesn't do so. Well this seems to be the main conflict between those who would like Python to go a bit further and those that oppose it. Should the priority be to enable python's philosophy or should it be the priority to limit python to only allow it's philosophy. One groups seems to think that python's spirit is not broken by allowing things that seem counter to it, as long as people can without much trouble, work within that spirit. An other group seems to think that any allowance to disgress from python's spirit is an assault on it. And exactly what is python's spirit/philosophy ? It seems to me that they are often used in a liberal way, just to support one's argument that whatever is not in the CURRENT python should not be there. -- http://mail.python.org/mailman/listinfo/python-list
Re: Why is dictionary.keys() a list and not a set?
[EMAIL PROTECTED] schrieb:
And this, again from the doc(about mapping objects):
A mapping object maps immutable values to arbitrary objects.
Seems that is questionable too.
a=(1,[])
d={}
d[a]=1
again would give TypeError, list object are unhashable.
That's a good example showing that the term 'mutable' is not so
well-defined as it may seem.
If you set b=[]; a=(1,b); should a be considered mutable (because you
can change its value by changing b), or should it be considered
immutable (because it is a tuple)?
-- Christoph
--
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Re: Guification of console app
Yes, I'll try to give you an example: you have a compression utility that works as a standard *nix filter, so it takes something from stdin and gives it back compressed to stdout you like to use it as such, because it's nice to call it from the command line now someone finds your utility quite nice, and says it would be nice to have a GUI that shows you, for example, how long it will take to compress... one way for sure it would be to fork your app, but this would be a waste of time you'd like to reuse the compression library you've already written for your GUI and your console, but: - you'd like to have your console app clean and simple, such as: import sys import CompressLib data = sys.stdin.read() cdata = CompressLib.compress(data) print cdata but you'd like the GUI to show some progress and status info. I guess the way is still to make the compress call split in microsteps and have the app call it, so you can use an EVT_IDLE call from the GUI, but maybe there's a better way... Thanks again Peter Hansen ha scritto: metiu wrote: Say I have a console app that does something in three steps: - opens a file - transfers the file through a serial port - does some elaborations and I want to build a GUI around it that, for example, sets the file name to open or starts the different steps. I started using wxPython (actually boa-constructor) to build a frame with everything I want. The problem is: when the console app method is working, the GUI is locked... How can the console app communicate with the GUI in order to make it tick (think of status messages, progress bars, log messages...)? If I use threads and events, or wxYield, or EVT_IDLE, I'm tweaking the console app so that it won't work just in console anymore. Could you please explain what makes this a console app, specifically? You are proposing wrapping a GUI around it, which would make it not a console app (by definition), so it would help if you specified exactly what elements (which functions, etc.) cause you to label it a console app. (For example, maybe it calls msvcrt.kbhit/getch or something...) The reason for asking is that the specifics of your answer will make it easier to describe how to modify this console so that the relevant parts work equally well as a _real_ console app (no GUI) or with the GUI. We could describe it in more general terms, but it might not be apparent how to adapt that to your own case. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Problem with HtmlWindow and Widgets
Hello I have problem with HtmlWindow and Widgets (wxPython). When I put on HtmlWindow TextCtrl all is ok, but when I try to use ComboBox then all controls not refresh. Where is problem? Thenks for help and sorry for my english ;) -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Alex Martelli wrote: Fuzzyman [EMAIL PROTECTED] wrote: There is already an update method of course. :-) Slicing an ordered dictionary is interesting - but how many people are actually going to use it ? (What's your use case) I detest and abhor almost-sequences which can't be sliced (I consider that a defect of collections.deque). If the ordered dictionary records by its sequencing the time order of key insertion, being able to ask for the last 5 keys entered or the first 3 keys entered seem to me to be perfectly natural use cases, and most naturally accomplished by slicing of course, d[-5:] and d[:3] respectively. If you slice an ordered dictionary, I assume you would expect to get an ordered dictionary back ? Fuzzyman http://www.voidspace.org.uk/python/index.shtml Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: sending all key events to wx.panel?
KvS wrote: Hi all, I have a wxPython GUI consisting of a wxWindow - wxPanel - set of widgets. I need to catch pressed keys no matter which widget has focus, so I've attached an event handler to the panel but I can't seem to find a way to do some kind of collective sending through of the key event from all the widgets on the panel to that handler in case the panel doesn't have focus. Is there some way to do this? Thanks in advance! - Kees Why not just attach the event handler to the wxWindow containing the panel? If the panel ignores keyboard events they'll just rise to the containing window, won't they? regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Sure - that was just an example of mutating the keys list without having direct access to it. If keys was implemented as an object (with a ``__call__`` method) then we could also implement sequence methods on it - making it easier to mutate the keys/values/items directly. All the best, Fuzzyman http://www.voidspace.org.uk/python/index.shtml -- http://mail.python.org/mailman/listinfo/python-list
Re: Draw a triangle...
Fredrik Lundh wrote: The Eternal Squire wrote: PyGame is your best bet for pure graphics. Simple shapes can be done in just a few statements. the same applies to Tkinter, of course. from Tkinter import * # set things up c = Canvas(); c.pack() # draw stuff c.create_polygon((0, 100, 50, 0, 100, 100), fill=red) # get things going mainloop() at the draw a triangle level, the main difference is mostly that Tkinter is a bit more likely to be installed on your machine... Out of curiousity : why not : c = Canvas() c.pack() -- http://mail.python.org/mailman/listinfo/python-list
Re: Making immutable instances
Mike Meyer [EMAIL PROTECTED] writes:
There isn't a standard serialize method in Python, so I don't know how
you want to define it.
Well, consider pickle, for example.
I can think of perfectly reasonable definitions
of serialize where obj.serialize() won't always return the same string
on an immutable object, even if you don't allow adding attributes.
Fair enough. How's this:
a = ImmutableObject()
b = deepcopy(a)
assert a == b # a and b start out equal
do stuff
# since a and b are immutable, they should still be equal
# no matter what has happened above
assert a == b
If you've added attributes to a but not to b, they should compare
unequal, breaking immutability.
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Re: Making immutable instances
Paul Rubin wrote: Fair enough. How's this: a = ImmutableObject() b = deepcopy(a) assert a == b # a and b start out equal do stuff # since a and b are immutable, they should still be equal # no matter what has happened above assert a == b If you've added attributes to a but not to b, they should compare unequal, breaking immutability. How about this ? a=(1,[]) b=copy.deepcopy(a) assert a==b # True a[1].append(1) assert a!=b -- http://mail.python.org/mailman/listinfo/python-list
Re: return in loop for ?
Steven D'Aprano wrote: On Thu, 24 Nov 2005 12:51:34 +, Duncan Booth wrote: Steven D'Aprano wrote: While outwardly they apear to offer a technique for making software more reliable there are two shortcomings I'm leery of. First, no verification program can verify itself; That's not a problem if there exists a verification program A which can't verify itself but can verify program B, which in turn also can't verify itself but will verify program A. That is logically equivalent to the first case, so it doesn't get you anywhere. (Just combine A and B into a single program which invokes A unless the input is A when it invokes B instead.) Then there you go, there is a single program which can verify itself. I think you are confabulating the impossibility of any program which can verify ALL programs (including itself) with the impossibility of a program verifying itself. Programs which operate on their own source code do not violate the Halting Problem. Neither do programs which verify some subset of the set of all possibly programs. There seems to have been some misattribution in recent messages, since I believe it was *me* who raised doubts about a program verifying itself. This has nothing to do with the Halting Problem at all. A very simple possible verification program is one that outputs True for any input. This will also verify itself. Unfortunately its output will be invalid in that and many other cases. I maintain that we cannot rely on any program's assertions about its own formal correctness. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Why is dictionary.keys() a list and not a set?
As a general note, I think it would be good to place the exact description in a footnote, since speaking about hashable objects, __hash__ and __cmp__ will certainly frighten off newbies and make it hard to read even for experienced users. The main text may lie/simplyfy a little bit. Or as Donald Knuth once recommended: Simplify. Lie, if it helps. You can add the correct details later on, but it is essential to present the reader with something straightforward to start off with. So don’t be afraid to bend the facts initially where this leads to a useful simplification and then pay back the debt to truth later by gradual elaborations. However, since the Python docs are a reference and not a textbook or manual, I think the debt should not be payed back later, but immediately in a footnote. The docs already follow this principle very well, e.g.: http://docs.python.org/lib/typesmapping.html -- Christoph -- http://mail.python.org/mailman/listinfo/python-list
Re: Guification of console app
metiu wrote: you have a compression utility that works as a standard *nix filter, so it takes something from stdin and gives it back compressed to stdout you like to use it as such, because it's nice to call it from the command line now someone finds your utility quite nice, and says it would be nice to have a GUI that shows you, for example, how long it will take to compress... one way for sure it would be to fork your app, but this would be a waste of time you'd like to reuse the compression library you've already written for your GUI and your console, but: - you'd like to have your console app clean and simple, such as: import sys import CompressLib data = sys.stdin.read() cdata = CompressLib.compress(data) print cdata but you'd like the GUI to show some progress and status info. here's a simple, stupid, and portable solution. the first script simulates your compression utility: # compress.py (simulator) import time, sys for i in range(100): sys.stdout.write(.) sys.stderr.write(%d%% done\r % i) sys.stderr.flush() time.sleep(0.1) (it prints N% done messages to stderr during the compression) the second script simulates your GUI. the stuff in the while loop should be run by a timer/alarm function, at regular intervals: import re, subprocess, time, os class monitor: # looks for N% done messages in the output stream def __init__(self, tfile): # could use dup/reopen instead self.file = open(tfile.name, r) def poll(self): pos = self.file.tell() data = self.file.read() if data: data = re.findall((\d+)% done, data) if not data: self.file.seek(pos) else: return int(data[-1]) def close(self): self.file.close() ifile = open(in.txt, rb) ofile = open(out.dat, wb) tfile = open(out.tmp~, wb) p = subprocess.Popen( python compress.py, stdin=ifile, stdout=ofile, stderr=tfile, ) m = monitor(tfile) while 1: # this should be placed in a background task that's called # every second or so if p.poll() is not None: print DONE break status = m.poll() if status is not None: # update status monitor print status, PERCENT DONE # wait a while before calling the background task again print . time.sleep(0.5) # clean up ifile.close() ofile.close() m.close() name = tfile.name tfile.close() os.remove(name) if you limit yourself to Unix only, you can simplify things quite a bit (e.g. using a pipe instead of the temporary file and use select to poll it, or use dup/reopen tricks to avoid opening the temporary file twice; if you do the latter, you can also use safe tempfile creation methods (see the tempfile method for details. etc). hope this helps! /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing big XML files where beginning depends on end.
Magnus Lycka wrote: This won't help if we have problems keeping the whole structure / call graph in memory at one time. Ah, I had assumed that the main problem was just that the resulting DOM was too big. Still, I don't think there would be a problem if you just constructed a very small tree and then wrote out XML based upon that, instead of using an external library for this. For example, if your only elements are node and leaf, you can store that distinction in 1 bit, as opposed to a library's naive implementation using the strings node and leaf, probably 40 bits in each case. Similarly you can calculate the aggregate attributes on the fly when it comes to outputting the tree instead of storing them. -- Ben Sizer -- http://mail.python.org/mailman/listinfo/python-list
Re: ftplib question - ftp.dir() returns something and ftp.nlst() does not
it's not obvious how Python could translate '' to anything other than an empty list, so it sure looks like a server issue. (or is a problem with running in passive mode? can you test with- out using passive mode on the same server?) I thought using ftp.set_pasv(0) sets active mode so I can use ftp.anyMethod() wihtout using passive mode? I tried: ftp.set_pasv(0) ftp.nlst() *cmd* 'TYPE A' *put* 'TYPE A\r\n' *get* '200 Type set to I.\r\n' *resp* '200 Type set to I.' *cmd* 'PORT 10,30,1,31,128,19' *put* 'PORT 10,30,1,31,128,19\r\n' *get* '200 PORT command Ok.\r\n' *resp* '200 PORT command Ok.' *cmd* 'NLST' *put* 'NLST\r\n' *get* '150 About to open data connection.\r\n' *resp* '150 About to open data connection.' *retr* '' *get* '226 Transfer complete.\r\n' *resp* '226 Transfer complete.' [] ftp.dir() -r--r--r-- 1 ownergroup 121984 Nov 24 12:13 member.dat -r--r--r-- 1 ownergroup 115 Nov 24 15:53 status.dat -r--r--r-- 1 ownergroup 339 Nov 24 15:53 debug.txt Nico -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Delaney, Timothy (Tim) wrote: It is without a doubt though incumbent on anyone proposing new *features* to have a solid understanding of what they are proposing, what it would affect, any backwards incompatibilities, and whether it fits into the python philosophy (import this). Sure. However, I wasn't just thinking about feature suggestions, but about times when people are asking about the best algorithm to use or why Python doesn't have something they used to rely upon in another language. And this is the crux of it - the majority of such proposals come from people who apparently haven't actually used python that much, and are trying to impose things from other languages onto it. The problem you get, is that the only people who are ever likely to need to ask questions, are those who don't fully understand Python, by definition. Often the answer they get is unintuitive to anyone not familiar with Python, but occasionally you are additionally treated as if you should have known and that thinking otherwise is a bit stupid, which is a bit unfair. In some cases, the question is quite valid, but the Python community has ossified around their own particular approach, which is not necessarily optimal but seems to be enough for all concerned. (eg. the proliferation of web frameworks that holds Python back as a platform in that area.) -- Ben Sizer -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Fuzzyman wrote: That means making keys, values, and items custom objects. Creating a new instance would have the overhead of creating 4 new objects instead of just 1. Is the added convenience worth it ? (Plus the extra layers of method calls for each access). I'm not sure about that either. But since you are using odict for convenience reasons anyway, and not for performance reasons, it would be consequential. Performance testing should be made anyway, so this could be tested as well. I think that creating these 3 additional objects will not matter much if the dict has more than a handful of items. And the extra layers will be only called if you really access these keys, values or items attributes which will not happen very frequently. Normally, you just loop over an ordered directory and acess keyed values. I'm not sure. It's a nice idea in terms of using it (we could just leave the sequence attribute as an alias for the new keys attribute - for backwards compatibility). Yes, you could make it a deprecated feature. -- Christoph -- http://mail.python.org/mailman/listinfo/python-list
books: Dive into Python vs Beginning Python
Hi, which of the following books would you recommend: Dive into Python or Beginning Python: From Novice to Professional? I'm an experienced C++-programmer who wants to take a look at Python. Thanks, Franz -- http://mail.python.org/mailman/listinfo/python-list
How to use _ in interactive mode
Hi,
I use '_' for localization in my program. The problem is when testing
the program using python intractive mode I lose _ function.
One solution is put following in PYTHONSTARTUP file.
--
import readline
def __enforce_underscore__ (): __builtins__._ = str
readline.set_pre_input_hook (__enforce_underscore__)
--
My program in startup imports a module which customize the env.
Putting above in that module doesn't solve the problem. Any
cleaner/better way?
Honestly, I was expecting once overriden _ in builtins it would be honored.
This how I reproduce the problem.
Python 2.3.3 (#1, May 7 2004, 10:31:40)
def localizer(s): return str(s)
__builtins__.__dict__['_'] = localizer
_
function localizer at 0xb7f6e844
_('some text')
'some text'
_
'some text'
_('some text')
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: 'str' object is not callable
TIA.
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Python book for a non-programmer
I have a non-programming friend who wants to learn Python. It's been so long since I've been in her shoes that I don't feel qualified to judge the books aimed at people in her situation. I know of two such books: http://www.freenetpages.co.uk/hp/alan.gauld/ http://www.ibiblio.org/obp/thinkCSpy/ Any recommendations, or otherwise? -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Ben Sizer wrote: The problem you get, is that the only people who are ever likely to need to ask questions, are those who don't fully understand Python, by definition. really? I'd say that most people that ask questions on comp.lang.python do understand Python pretty well, and just needs help with some esoteric detail, or some part of a library that they haven't used before. And the most common response is oh, that's cool. thanks. The I'm personally offended by the very design of the feature you just pointed me to kind of person is not very common; most people don't have that kind of ego pro- blem, and even those who do usually don't have time for that kind of crap. Fact is, most people see Python as a tool, use it where it fits, and focus on the problems they need the tool for. And yes, most Python users never gets anywhere near comp.lang.python. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python book for a non-programmer
http://www.python.org/doc/Intros.html and two great texts when she has covered the basics are: http://diveintopython.org/ http://www.mindview.net/Books/TIPython -- http://mail.python.org/mailman/listinfo/python-list
Re: problem compiling executable with py2exe
tim [EMAIL PROTECTED] wrote:
I used py2exe before with more complex programs without any problem.
Now, although my program works fine when I run it from PythonWin, it
won't compile to an executable.
are you sure you're generating a console executable? your program needs
access to the console:
d=raw_input('path')
s=int(raw_input('maxsize (in bytes):'))
but
Traceback (most recent call last):
File filesizechecker.py, line 4, in ?
EOFError: EOF when reading a line
indicates that it doesn't have one.
/F
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Re: Python book for a non-programmer
Simon Brunning wrote: I have a non-programming friend who wants to learn Python. It's been so long since I've been in her shoes that I don't feel qualified to judge the books aimed at people in her situation. I know of two such books: http://www.freenetpages.co.uk/hp/alan.gauld/ http://www.ibiblio.org/obp/thinkCSpy/ Any recommendations, or otherwise? -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ If you want real (dead-tree) books, you will find Chris Fehily's Visual Quickstart Guide recommended by others here (though it's ageing - 2002). I'm about 2/3 through and it's been great for me: http://www.amazon.com/exec/obidos/asin/0201748843/richarddooling/ And a brand new one which I just ordered: Beginning Python (Programmer To Programmer) which despite the title has a great intro to programming before it quickly accelerates: http://www.amazon.com/exec/obidos/asin/0764596543/richarddooling/ Cheers, bs -- http://mail.python.org/mailman/listinfo/python-list
Re: sending all key events to wx.panel?
I've tried, by setting self.Bind(wx.EVT_CHAR, self.handleKeybEv, self) in the top level frame, but still this only works if the panel has focus and not if e.g. a button on the panel has focus while a key is pressed... In the meantime I found this: In some cases, it might be desired by the programmer to get a certain number of system events in a parent window, for example all key events sent to, but not used by, the native controls in a dialog. In this case, a special event handler will have to be written that will override ProcessEvent() in order to pass all events (or any selection of them) to the parent window. in wxPython docupart on event handling. Anybody who has done something like that before? - Kees -- http://mail.python.org/mailman/listinfo/python-list
Stealing focus: emacs, and PIL, in Windows
I'm using GNU Emacs 21.3.1 with python-mode 1.0alpha under Windows XP. Whenever I execute a command in an edit window (with py-execute-region), the output window steals the focus. How can I stop this happening? I don't know any lisp, but I hacked together this routine so that that when I press ctrl+return the entire current block is executed. (defun py-execute-paragraph (vis) Send the current paragraph to Python Don't know what vis does. (interactive P) (save-excursion (forward-paragraph) (let ((end (point))) (backward-paragraph) (py-execute-region (point) end (global-set-key [(ctrl return)] 'py-execute-paragraph) It seems to me (though I could well be wrong) that the focus stays in the edit window during the execution of this command (thanks to save-excursion); but the focus shifts to the command window whenever there is output, in this case a new prompt , in the routine py-comint-output-filter-function. I commented out the command (pop-to-buffer (current-buffer)) and now the command window no longer steals focus. But I don't know if this has any other side effects, or it there's a better way to prevent focus being stolen. Damon. -- http://mail.python.org/mailman/listinfo/python-list
Stealing focus: PIL
I'm using the Python Image Library (PIL) for Python 2.4.
If I have an image and I show it
from PIL import Image
im = Image.new('RGB',100,100)
im.show()
then the output window steals focus. It's very handy to use
an image to show the progress of execution for my program,
but the computer is unusable when focus keeps on being stolen
every few seconds. How can I prevent Image.show() from stealing
focus?
Damon.
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Re: Guification of console app
I like it! Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: books: Dive into Python vs Beginning Python
Franz Mueller wrote:
Hi,
which of the following books would you recommend:
Dive into Python or Beginning Python: From Novice to Professional?
I can't recommand the second since I've never read it. But you can
freely make your own opinion on the first, since it's freely available
online.
I'm an experienced C++-programmer who wants to take a look at Python.
Then I'd say that Dive into Python may be a good choice.
Welcome BTW
--
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: Python book for a non-programmer
On 25 Nov 2005 03:23:33 -0800, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: http://www.python.org/doc/Intros.html and two great texts when she has covered the basics are: http://diveintopython.org/ http://www.mindview.net/Books/TIPython I wouldn't have thought either of those was suitable for a non-programmer. Great for cross-trainers, yes, but neither is intended as a programming tutorial. -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python book for a non-programmer
Read my reply here from another thread: http://groups.google.com/group/comp.lang.python/browse_thread/thread/25aada3c22ce6e66/cc69fd0c78384e5b?q=luis+cogliati'srnum=1#cc69fd0c78384e5b -- http://mail.python.org/mailman/listinfo/python-list
Singleton and C extensions
I am participating in the development of a GPL IDE https://libre2.adacore.com/gps/ It is written in Ada, but provides an extensive extensibility through Python. I am not really good at python, but I was trying to implement the singleton design pattern in C, so that for instance calling the constructor ed = Editor (foo) would either return an existing instance of Editor currently editing foo, or would create a new instance. Basically, one python instance is stored inside each of the visual windows representing an editor, and I want to get that instance if it already exists, instead of creating a new one each time. I basically would like ed = Editor (foo) ed.attribute = whatever print Editor (foo).attribute to print whatever Has any one an example on how to do that in C, or maybe even at the python level itself, and I will try to adapt it ? Thanks in advance Emmanuel -- http://mail.python.org/mailman/listinfo/python-list
Re: Guification of console app
On 11/25/05, Fredrik Lundh [EMAIL PROTECTED] wrote: metiu wrote: you have a compression utility that works as a standard *nix filter, so it takes something from stdin and gives it back compressed to stdout you like to use it as such, because it's nice to call it from the command line now someone finds your utility quite nice, and says it would be nice to have a GUI that shows you, for example, how long it will take to compress... one way for sure it would be to fork your app, but this would be a waste of time you'd like to reuse the compression library you've already written for your GUI and your console, but: - you'd like to have your console app clean and simple, such as: import sys import CompressLib data = sys.stdin.read() cdata = CompressLib.compress(data) print cdata but you'd like the GUI to show some progress and status info. here's a simple, stupid, and portable solution. the first script simulates your compression utility: # compress.py (simulator) import time, sys for i in range(100): sys.stdout.write(.) sys.stderr.write(%d%% done\r % i) sys.stderr.flush() time.sleep(0.1) (it prints N% done messages to stderr during the compression) the second script simulates your GUI. the stuff in the while loop should be run by a timer/alarm function, at regular intervals: import re, subprocess, time, os class monitor: # looks for N% done messages in the output stream def __init__(self, tfile): # could use dup/reopen instead self.file = open(tfile.name, r) def poll(self): pos = self.file.tell() data = self.file.read() if data: data = re.findall((\d+)% done, data) if not data: self.file.seek(pos) else: return int(data[-1]) def close(self): self.file.close() ifile = open(in.txt, rb) ofile = open(out.dat, wb) tfile = open(out.tmp~, wb) p = subprocess.Popen( python compress.py, stdin=ifile, stdout=ofile, stderr=tfile, ) m = monitor(tfile) while 1: # this should be placed in a background task that's called # every second or so if p.poll() is not None: print DONE break status = m.poll() if status is not None: # update status monitor print status, PERCENT DONE # wait a while before calling the background task again print . time.sleep(0.5) # clean up ifile.close() ofile.close() m.close() name = tfile.name tfile.close() os.remove(name) if you limit yourself to Unix only, you can simplify things quite a bit (e.g. using a pipe instead of the temporary file and use select to poll it, or use dup/reopen tricks to avoid opening the temporary file twice; if you do the latter, you can also use safe tempfile creation methods (see the tempfile method for details. etc). hope this helps! /F If you are using wxPython, you can skip writing this scaffolding yourself and use wx.Execute and wx.Process, which will allow you to execute other processes and re-direct thier input and output. The wxPython demo has an example. -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Persist a class (not an instance)
Is there a way to persist a class definition (not a class instance, the actual class) so it can be restored later? A naive approach using pickle doesn't work: import pickle class Foo(object): ... def show(self): ... print I'm a Foo ... p = pickle.dumps(Foo) p 'c__main__\nFoo\np0\n.' Hmm, doesn't look too promising. In a new interpreter: import pickle p='c__main__\nFoo\np0\n.' Foo = pickle.loads(p) Traceback (most recent call last): File stdin, line 1, in ? File C:\Python24\lib\pickle.py, line 1394, in loads return Unpickler(file).load() File C:\Python24\lib\pickle.py, line 872, in load dispatch[key](self) File C:\Python24\lib\pickle.py, line 1104, in load_global klass = self.find_class(module, name) File C:\Python24\lib\pickle.py, line 1140, in find_class klass = getattr(mod, name) AttributeError: 'module' object has no attribute 'Foo' The idea is to persist classes that are created and modified at runtime. Thanks, Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: Python book for a non-programmer
Simon Brunning wrote: I wouldn't have thought either of those was suitable for a non-programmer. Great for cross-trainers, yes, but neither is intended as a programming tutorial. I agree, I just thought that the other replies had provided more than enough resources to cover the basics, so I was just suggesting some material that could be used when the basics had been absorbed. Sorry about the confusion. -- http://mail.python.org/mailman/listinfo/python-list
How to get started in GUI Programming?
I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. I am not an experienced programmer - just someone who from time to time writes small programs for my use. Over the years I have moved from GWBASIC to QBASIC to Visual Basic, and now trying to move across to a Linux platform. Python seems to be the best compromise between the limitations of command line basic programming and the total incomprehensibility of C. Googling around it seems the best GUI is either Tkinter or PyGtk. I found a book which recommended PyGtk, as it had a graphical design option, Glade. Coming from a VB background I latched onto that and bought the book (Beginning Python, Wrox), but it was a disappointment (or more accurately a complete waste of money) - there was insufficient detail in the text. I've found the tutorial and reference manual on the PyGtk web site, but although I've made some progress, I keep reaching points where I have insufficient background to understand them. Currently I'm stuck on dialog boxes (the code seems immensely complex for the equivalent of MsgBox(Do you really want to do this ,vbYesNo) and I haven't got it to work properly yet) and loading graphical images in anything other than their original size, but every new step brings another struggle I've seen reference to a Tkinter book - something like 'Python and Tkinter Programming' but it seems to be out of print and unavailable. Can anyone offer any suggestions as to the least painful way forwards? (Email address was valid once but has long since been abandoned to spam. Please rely via newsgroup) -- http://mail.python.org/mailman/listinfo/python-list
Re: Singleton and C extensions
Emmanuel Briot wrote:
I am participating in the development of a GPL IDE
https://libre2.adacore.com/gps/
It is written in Ada, but provides an extensive extensibility through
Python.
I am not really good at python, but I was trying to implement the
singleton design pattern in C, so that for instance calling the constructor
ed = Editor (foo)
would either return an existing instance of Editor currently editing
foo, or would create a new instance. Basically, one python instance is
stored inside each of the visual windows representing an editor, and I
want to get that instance if it already exists, instead of creating a
new one each time.
I basically would like
ed = Editor (foo)
ed.attribute = whatever
print Editor (foo).attribute
to print whatever
Has any one an example on how to do that in C, or maybe even at the
python level itself, and I will try to adapt it ?
use a factory function instead of the class, and let the function create an
editor
instance when needed:
_editors = {}
def Editor(name):
try:
editor = _editors[name]
except KeyError:
editor = _editors[name] = EditorImplementation()
editor.setname(name)
...
return editor
if you really need singleton, click here:
http://www.google.com/search?q=python+borg+pattern
/F
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Re: How to get started in GUI Programming?
[EMAIL PROTECTED] enlightened us with: Googling around it seems the best GUI is either Tkinter or PyGtk. I'd go for wxPython ;-) 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: wxPython Licence vs GPL
Ed Jensen wrote: [On proprietary ports of Python...] Show me the harm done. We'll have to wait and see what happens. There's a risk that versions of Python with different semantics or characteristics to the original could cause the development of parallel communities, instead of everyone working on/with the same project. The harm done is adequately described by paraphrasing your comment on licences: think how much farther along free software could be if all this energy and concern weren't expended on separate and sometimes proprietary code bases. Because I think a lot of well meaning software developers writing free software don't performance due diligence to determine the true motivation behind, and the chilling effect of, the GPL. Well, despite your protestations, I think the GPL and LGPL are fairly easy and safe choices for a lot of developers who know enough about Free Software (ie. haven't just seen the name and thought that's the thing for me), know what the characteristics of those licences are, and who don't have the time or legal experience to performance due diligence. Meanwhile, all this hippie and chilling effect talk is, I imagine, like having a discussion on software licensing with some cold war propagandist. Paul -- http://mail.python.org/mailman/listinfo/python-list
Help need
HI group, During doing some codeing with python i got the inline error, def my_word( offset ): try: j = ord(t[offset]) + 256*ord(t[offset+1])# + 65536*ord(t [offset+2]) + 16777216*ord(t[offset+3]) #return j except IndexError: # print Exception return j def my_bpp( mode ): if mode 0xF800: return 1 ( ( (mode 27) 31 ) - 1 ) if mode==20 or mode==27: return 4 return 0 File ../../../source/ant//tools/scripts/python/sprites.py, line 31 j = ord(t[offset]) + 256*ord(t[offset+1])# + 65536*ord(t [offset+2]) + 16777216*ord(t[offset+3]) ^ IndentationError: expected an indented block make[2]: *** [swapped.out] Error 1 make[1]: *** [ant_final_target] Error 2 make: *** [rest] Error 2 Any Help? With Best Regards, Soumya -- http://mail.python.org/mailman/listinfo/python-list
Re: Persist a class (not an instance)
Kent Johnson enlightened us with: Is there a way to persist a class definition (not a class instance, the actual class) so it can be restored later? From the docs: Similarly, classes are pickled by named reference, so the same restrictions in the unpickling environment apply. Note that none of the class's code or data is pickled [...] 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: How to get started in GUI Programming?
Am Fri, 25 Nov 2005 06:02:40 -0800 schrieb peter.mosley: I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. Yes, if you come from Visual Basic you might be missing something. I developed with Visual Basic some time ago and like some parts of it. I've found the tutorial and reference manual on the PyGtk web site, but although I've made some progress, I keep reaching points where I have insufficient background to understand them. Currently I'm stuck on dialog boxes (the code seems immensely complex for the equivalent of MsgBox(Do you really want to do this ,vbYesNo) search for yesNoDialog here: http://guettli.sourceforge.net/gthumpy/src/editMetadata.py and I haven't got it to work properly yet) and loading graphical images in anything other than their original size, but every new step brings another struggle search for scale2pixbuf in the link. Can anyone offer any suggestions as to the least painful way forwards? Only the beginning is painful. After some time you don't miss anything from Visual Basic anymore. Happy Learning, Thomas -- Thomas Güttler, http://www.thomas-guettler.de/ E-Mail: guettli (*) thomas-guettler + de Spam Catcher: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
[EMAIL PROTECTED] wrote: And exactly what is python's spirit/philosophy ? It seems to me that they are often used in a liberal way, just to support one's argument that whatever is not in the CURRENT python should not be there. Yes, those contentious terms pythonic and unpythonic which, as someone recently pointed out, appear to be convenient tools to respectively label one's own work as acceptable and someone else's work as deficient. I certainly don't have much time for people who, after the most cursory inspection of Python, proclaim that it is substandard for not having static typing or for employing indentation to organise source code, but I do believe that people shouldn't be given the brush-off on more subtle topics by some Zen of Python remark (probably not even supported by the classic Tim Peters text). It should be noted that Zope eventually experienced something of a backlash by encouraging such a culture of obscure wisdom, and sometimes Python risks experiencing some of the same. More documentation, explanation and objective discussion help to bring the newcomer to understanding, rather than alienating them with some kind of opaque, elitist retort which gives them no clue as to how they may reach such understanding. Paul -- http://mail.python.org/mailman/listinfo/python-list
Accessing Outlook Public Folders
Hi, I'm new to Python and I want to create a script that will import contactitems into an Outlook Public Folder. Therefore I've installed the Python for Windows Extensions. This way I can access my personal contacts code import win32com.client OutlookObj = win32com.client.Dispatch(Outlook.Application) Nms = OutlookObj.GetNameSpace(MAPI) # Personal contacts folder custs = Nms.GetDefaultFolder(10).Items print custs.count for i in range(custs.count): cust = custs[i] print cust.FullName + - + cust.FileAs /code But when I try to access contacts in the public folder 'klanten' with this code I get an error. code import win32com.client OutlookObj = win32com.client.Dispatch(Outlook.Application) Nms = OutlookObj.GetNameSpace(MAPI) # Folder Klanten from public folders custs = Nms.Folders.Item(Public Folders).Folders.Item(All Public Folders).Folders[Klanten].Items print custs.count for i in range(custs.count): cust = custs[i] print cust.FullName + - + cust.FileAs /code error Traceback (most recent call last): File D:\PythonScripts\tp2outlook.py, line 13, in -toplevel- print cust.FullName + - + cust.FileAs File D:\Python23\Lib\site-packages\win32com\client\dynamic.py, line 489, in __getattr__ raise AttributeError, %s.%s % (self._username_, attr) AttributeError: unknown.FullName /error Anyone an idea how I can access those contactitems? Thanks, Bob -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
On 11/25/05, Sybren Stuvel [EMAIL PROTECTED] I'd go for wxPython ;-) I'd go for Dabo, which is a Pythonic wrapper around wxPython. They are even working on a visual design tool to lay out your UI, much as you would in Visual Basic. -- # p.d. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python book for a non-programmer
Simon Brunning wrote: I have a non-programming friend who wants to learn Python. It's been so long since I've been in her shoes that I don't feel qualified to judge the books aimed at people in her situation. Python Programming for the absolute beginner http://premierpressbooks.com/ptr_detail.cfm?group=Programmingisbn=1%2D59200%2D073%2D8 Python Programming: An Introduction to Computer Science http://www.fbeedle.com/99-6.html And the Introductory Books page in the wiki lists many: http://wiki.python.org/moin/IntroductoryBooks Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
have you tried gtk.MessageDialog ? http://www.pygtk.org/pygtk2reference/class-gtkmessagedialog.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Help need
sr_sutar wrote: HI group, During doing some codeing with python i got the inline error, def my_word( offset ): try: j = ord(t[offset]) + 256*ord(t[offset+1])# + 65536*ord(t [offset+2]) + 16777216*ord(t[offset+3]) #return j except IndexError: # print Exception return j def my_bpp( mode ): if mode 0xF800: return 1 ( ( (mode 27) 31 ) - 1 ) if mode==20 or mode==27: return 4 return 0 File ../../../source/ant//tools/scripts/python/sprites.py, line 31 j = ord(t[offset]) + 256*ord(t[offset+1])# + 65536*ord(t [offset+2]) + 16777216*ord(t[offset+3]) ^ IndentationError: expected an indented block make[2]: *** [swapped.out] Error 1 make[1]: *** [ant_final_target] Error 2 make: *** [rest] Error 2 Any Help? The except clause requires an indented suite, which you've commented out. You might also want to look at the struct modlue if you want to convert 4 bytes into an integer. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python book for a non-programmer
I recommend The Quick Python Book by Daryl Harms. What makes it different from all other introductory books is that it is actually *readable*. You can just sit down and read it like a novel and enjoy it. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
Can anyone offer any suggestions as to the least painful way forwards? http://www.ferg.org/easygui/index.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Persist a class (not an instance)
Sybren Stuvel wrote: Kent Johnson enlightened us with: Is there a way to persist a class definition (not a class instance, the actual class) so it can be restored later? From the docs: Similarly, classes are pickled by named reference, so the same restrictions in the unpickling environment apply. Note that none of the class's code or data is pickled [...] OK that confirms that pickle won't work. Is there another approach that will? Kent -- http://mail.python.org/mailman/listinfo/python-list
Dynamic classes
Hello all. I was wondering if creating classes could be dynamic. I want to know if I can make a class Person, then read in a list of names (say people's names) so then I can have a class instance created for each name in the list? Why do I want to do this? I was just thinking if I had a name on the list, Dave, I could then be able to read the name in the list, and assign Maria.birthday = and all the other attributes I would want to use a class for, except this is dynamic. I don't know how to iterate thru the list to assign the different attributes yet, but this seemed reasonable to want to do, and thought I could learn from this. Thanks! Dave -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
Hello Peter, I am going to recommend EasyGui which can be found at http://www.ferg.org/easygui/ because it is (by far) the easiest possible GUI creation tool using Python. If (or when) your needs require more complex options than easygui provides, you might try looking at my GUI toolkits page, http://www.awaretek.com/toolkits.html which has short descriptions of and links to several Python GUI toolkits. Among these, my personal favorite is PythonCard which is a framework that uses a visual GUI creation tool and uses the wxPython widgets. I have found PythonCard to be much easier to get started with than Glade. I also did a podcast describing Python's GUI options, from a beginner's point of view, which can be found on my Python podcasts page, http://www.awaretek.com/python/index.html (scroll down to near the bottom to find the Choose Your GUI Toolkit podcast from back in July. But by all means don't forget to check out Easygui. Steve Ferg has made a tool that is incredibly simple to learn and use, and sometimes it sure is nice to get instant gratification by achieving quick success and useful results. ;-))) Ron Stephens a href=http://www.awaretek.com/plf.html;Python Learning Foundation/a -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
If you come from visual basic, I suggest to use pythoncard GUI, which is very simple to develop with a Ressource Editor (create a panel, see labwindows, visual basic ..). https://sourceforge.net/projects/vb2py/ a package to transform VB to pythoncard http://www.linux2000.com/pimp.html a pythoncard application Philippe DALET Lyp champollion 46100 FIGEAC FRANCE [EMAIL PROTECTED] a écrit : I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. I am not an experienced programmer - just someone who from time to time writes small programs for my use. Over the years I have moved from GWBASIC to QBASIC to Visual Basic, and now trying to move across to a Linux platform. Python seems to be the best compromise between the limitations of command line basic programming and the total incomprehensibility of C. Googling around it seems the best GUI is either Tkinter or PyGtk. I found a book which recommended PyGtk, as it had a graphical design option, Glade. Coming from a VB background I latched onto that and bought the book (Beginning Python, Wrox), but it was a disappointment (or more accurately a complete waste of money) - there was insufficient detail in the text. I've found the tutorial and reference manual on the PyGtk web site, but although I've made some progress, I keep reaching points where I have insufficient background to understand them. Currently I'm stuck on dialog boxes (the code seems immensely complex for the equivalent of MsgBox(Do you really want to do this ,vbYesNo) and I haven't got it to work properly yet) and loading graphical images in anything other than their original size, but every new step brings another struggle I've seen reference to a Tkinter book - something like 'Python and Tkinter Programming' but it seems to be out of print and unavailable. Can anyone offer any suggestions as to the least painful way forwards? (Email address was valid once but has long since been abandoned to spam. Please rely via newsgroup) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Should the priority be to enable python's philosophy or should it be the priority to limit python to only allow it's philosophy. One groups seems to think that python's spirit is not broken by allowing things that seem counter to it, as long as people can without much trouble, work within that spirit. An other group seems to think that any allowance to disgress from python's spirit is an assault on it. This seems to assume a background philosophy of TMTOWTDI versus YWKTMTOWTDIBIPFCEMS = .join([Yes we know,TMTOWTDI,But in Python fewer choices equals more simplicity) There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Maybe what makes Python most different is its philosophy; I would not argue it is the ultimate philosophy --- I could not embrace a government which held such views --- it is nothing like Democratic --- but the people in Pythonia tend to be fairly nice, and the tax rate is outstandingly low. Of course that's silly, Python is a tool, not a country. Python's philosophy, however, seems to run counter to adding a phillips head, flat head, and hex head screwdriver blade to its hammer. In life and society I hope we embrace a great multiplicity of perspectives and lifestyles. This, however, is not that. What is the philosophy? I'm not the one to answer that, but I do use import this for reference, and it seems to answer some of the points in this thread: import this The Zen of Python, by Tim Peters Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. Flat is better than nested. Sparse is better than dense. Readability counts. Special cases aren't special enough to break the rules. Although practicality beats purity. Errors should never pass silently. Unless explicitly silenced. In the face of ambiguity, refuse the temptation to guess. There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than *right* now. If the implementation is hard to explain, it's a bad idea. If the implementation is easy to explain, it may be a good idea. Namespaces are one honking great idea -- let's do more of those! EP Criminy, I didn't realize that drat ternary operator was going to creep in. Ugh. Drat, drat, drat! -- http://mail.python.org/mailman/listinfo/python-list
Re: FTP over TLS
Carl Waldbieser [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Does anyone know of any good examples for writing client side code to upload files over a secure FTP connection? http://trevp.net/tlslite/ Alan Isaac -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
The best, in my opinion is wxPython. I recommend getting wxGlade and just fiddling around. You should be able to produce some interesting GUI's fairly easily. -- http://mail.python.org/mailman/listinfo/python-list
Re: Persist a class (not an instance)
Kent Johnson enlightened us with: OK that confirms that pickle won't work. Is there another approach that will? Well, since the classes are created at runtime as well, you could compile them using the appropriate API and call exec() on them. 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
Modifying Unix ReadKey Code
I found this site that has code for readkey for Windows, Unix, and in an updated version, Mac: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/134892 . The Mac object returns a character whether or not a key was pressed. I modified the Windows object to do the same when I downloaded it, but I have no idea how to make the Unix object to do the same. Any help??? Not to be pushy, but I would like an answer soon. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
Search this group for PythonCard and wxPython for gobs of opinions. For descriptions of other resources, try: http://www.fredshack.com/docs/python.html bs -- http://mail.python.org/mailman/listinfo/python-list
Re: (newbie) N-uples from list of lists
This is my attempt :
def cross(seq):
r=[[]]
for x in seq:
r = [ a + b for a in r for b in [[i] for i in x ]]
return r
It is not very efficient though as it would loop through the
intermediate list produced multiple times.
[EMAIL PROTECTED] wrote:
Hello,
i think it could be done by using itertools functions even if i can not
see the trick. i would like to have all available n-uples from each
list of lists.
example for a list of 3 lists, but i should also be able to handle any
numbers of items (any len(lol))
lol = (['a0', 'a1', 'a2'], ['b0', 'b1'], ['c0', 'c1', 'c2', 'c3'])
=
[('a0', 'b0', 'c0'), ('a0', 'b0', 'c1'), ('a0', 'b0', 'c2'), ('a0',
'b0', 'c3'), ('a0', 'b1', 'c0'), ('a0', 'b1', 'c1'), ('a0', 'b1',
'c2'), ('a0', 'b1', 'c3'), ('a1', 'b0', 'c0'), ('a1', 'b0', 'c1'),
('a1', 'b0', 'c2'), ('a1', 'b0', 'c3'), ('a1', 'b1', 'c0'), ('a1',
'b1', 'c1'), ('a1', 'b1', 'c2'), ('a1', 'b1', 'c3'), ('a2', 'b0',
'c0'), ('a2', 'b0', 'c1'), ('a2', 'b0', 'c2'), ('a2', 'b0', 'c3'),
('a2', 'b1', 'c0'), ('a2', 'b1', 'c1'), ('a2', 'b1', 'c2'), ('a2',
'b1', 'c3')]
maybe tee(lol, len(lol)) can help ?
it could be done by a recursive call, but i am interested in using and
understanding generators.
i also have found a convenient function, here :
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65285 (paste
below)
but i am curious of how you will do it or refactorize this one with
generators...
def permuteflat(*args):
outs = []
olen = 1
tlen = len(args)
for seq in args:
olen = olen * len(seq)
for i in range(olen):
outs.append([None] * tlen)
plq = olen
for i in range(len(args)):
seq = args[i]
plq = plq / len(seq)
for j in range(olen):
si = (j / plq) % len(seq)
outs[j][i] = seq[si]
for i in range(olen):
outs[i] = tuple(outs[i])
return outs
many thanx
--
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Re: Python as Guido Intended
But suppose someone came up with a Python compiler. It would compile any Python program but there would be no speed benefit unless you carefully wrote the code to not use many of Python's dynamic features, so that either by type inferencing or programmer supplied static declarations, the compiler could generate efficient native machine code that executes at near C speeds. Obviously this would require changes (mostly additions?) to the Python language, though these changes would still allow today's style dynamic code to be written and run (though just as slow as today's runs). The payout would be that things written as C-extensions today, would be writable in (a restricted form of) Python. Would the Python orthodoxy favor such a development? Or would that be turning Python into a screwdriver? i agree with you... pyrex should be part of the python distribution :) bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: wxPython Licence vs GPL
Paul Boddie [EMAIL PROTECTED] wrote: We'll have to wait and see what happens. There's a risk that versions of Python with different semantics or characteristics to the original could cause the development of parallel communities, instead of everyone working on/with the same project. The harm done is adequately described by paraphrasing your comment on licences: think how much farther along free software could be if all this energy and concern weren't expended on separate and sometimes proprietary code bases. I think free software/open source has existed long enough and with enough varied licenses (GPL, LGPL, modified LGPL (see wxWidgets), BSD, X11, MIT, Apache, etc.) that we'd basically know without question if less restritive licenses (like BSD) were causing projects to fail vs. projects that use very heavy handed licenses (like GPL). Apache and Python are two of my favorite examples, followed by the *BSD operating systems. Well, despite your protestations, I think the GPL and LGPL are fairly easy and safe choices for a lot of developers who know enough about Free Software (ie. haven't just seen the name and thought that's the thing for me), know what the characteristics of those licences are, and who don't have the time or legal experience to performance due diligence. To be honest, I don't dislike the LGPL that much. The static vs. dynamic linking issues bother me somewhat (which is why I like the modified LGPL used by wxWidgets), but all in all, I can live (albeit uncomfortably) with LGPL. It seems much more sane. Whereas including one line of GPL code into your 10,000,000,000 line project can have disasterous consequences (which I find ridiculous), at least with LGPL you're only asked to share the changes you've made to that particular library. Meanwhile, all this hippie and chilling effect talk is, I imagine, like having a discussion on software licensing with some cold war propagandist. Sorry for my initial post on this subject being flamey. I must've been cranky that day, and I'm glad we were able to continue the discussion. :) -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
[EMAIL PROTECTED] wrote: I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. I am not an experienced programmer - just someone who from time to time writes small programs for my use. Over the years I have moved from GWBASIC to QBASIC to Visual Basic, and now trying to move across to a Linux platform. Python seems to be the best compromise between the limitations of command line basic programming and the total incomprehensibility of C. Googling around it seems the best GUI is either Tkinter or PyGtk. You might also want to try PyQt: http://www.riverbankcomputing.co.uk/pyqt/ I'm sure fans of wxWidgets will also point you in the direction of their favourite bindings. ;-) David -- http://mail.python.org/mailman/listinfo/python-list
Re: wxPython Licence vs GPL
Ed Jensen a écrit : Well, despite your protestations, I think the GPL and LGPL are fairly easy and safe choices for a lot of developers who know enough about Free Software (ie. haven't just seen the name and thought that's the thing for me), know what the characteristics of those licences are, and who don't have the time or legal experience to performance due diligence. To be honest, I don't dislike the LGPL that much. The static vs. dynamic linking issues bother me somewhat (which is why I like the modified LGPL used by wxWidgets), but all in all, I can live (albeit uncomfortably) with LGPL. It seems much more sane. Whereas including one line of GPL code into your 10,000,000,000 line project can have disasterous consequences (which I find ridiculous), at least with LGPL you're only asked to share the changes you've made to that particular library. If you don't like the GPL, then by all means, *do not use GPL code !* Please, I mean, when you use without authorisation some code in your project, you are in trouble, no matter what licence the code was using. -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
Fuzzyman [EMAIL PROTECTED] wrote: ... If you slice an ordered dictionary, I assume you would expect to get an ordered dictionary back ? That would be helpful, yes, though there are precedents for types whose slicing doesn't return an instance of that type (e.g. slices of an mmap are instances of str, not of mmap, if I recall correctly), most sliceable sequences do follow that pattern. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamic classes
Dave Rose [EMAIL PROTECTED] wrote: Hello all. I was wondering if creating classes could be dynamic. I want to know if I can make a class Person, then read in a list of names (say people's names) so then I can have a class instance created for each name in the list? Yes, but what you're asking for in your second sentence is different from what you're wondering about in your first one. You can create a class dynamically. You can create dynamically an instance of a class. The two things are quite separate issues. You create a new class each time you execute a 'class' statement, or call 'type' (or other custom metaclass) with suitable arguments. You can do either or both in the body of a loop over a list of names, say. You create a new instance of a class each time you call the class. Again, of course you can do this in a loop's body. Creating new classes is a reasonably rare need, creating new instances is a very common need. Perhaps you can clarify which one you mean? Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Persist a class (not an instance)
Kent Johnson [EMAIL PROTECTED] wrote: Is there a way to persist a class definition (not a class instance, the actual class) so it can be restored later? A naive approach using pickle doesn't work: You can use copy_reg to customize pickling behavior. In this case, you'd need a custom metaclass to use as the type for your picklable classes. Moreover, if the class has attributes that you also want to pickle, such as methods or properties, you'll have to arrange for custom pickling of *them*, too. So, yes, there are ways, but not simple ones. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: books: Dive into Python vs Beginning Python
In article [EMAIL PROTECTED], Franz Mueller [EMAIL PROTECTED] wrote: which of the following books would you recommend: Dive into Python or Beginning Python: From Novice to Professional? I'm an experienced C++-programmer who wants to take a look at Python. Another option: just use the on-line tutorial at python.org -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: books: Dive into Python vs Beginning Python
On 11/25/05, Franz Mueller [EMAIL PROTECTED] wrote: Hi, Hi Franz! :) which of the following books would you recommend: Dive into Python or Beginning Python: From Novice to Professional? Both are very good books but I suggest the latter because more recent. Beginning Python talk python 2.3 and 2.4 : set data structure, generator, iterator... -- Sébastien Douche [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamic classes
Dave Rose [EMAIL PROTECTED] (DR) wrote:
DR Hello all.
DR I was wondering if creating classes could be dynamic. I want to know
DR if I can make a class Person, then read in a list of names (say
DR people's names) so then I can have a class instance created for each
DR name in the list?
If you have the class Person, you are not creating it dynamically. And of
course you can create instances dynamically as you describe.
DR Why do I want to do this? I was just thinking if I had a name on the
DR list, Dave, I could then be able to read the name in the list, and
DR assign Maria.birthday = and all the other attributes I would want
DR to use a class for, except this is dynamic. I don't know how to
DR iterate thru the list to assign the different attributes yet, but this
DR seemed reasonable to want to do, and thought I could learn from this.
If I understand you correctly, you want to create a variable with name
'Maria' when you read the name Maria. Creating variables dynamically is
possible in Python but is almost always the wrong thing to do. Instead it
is usually better to use a dictionary.
class Person:
def __init__(self, name):
self.name = name
persons = {}
now you have a loop that reads persons' names, say in name.
myperson = persons[name] = Person(name)
Now I suppose you want to read additional attributes, while the list of
possible attributes is in principle open.
So suppose you have read the attribute name in attr and the value in val.
The you can dynamically create an instance attribute with:
setattr(myperson, attr, val)
--
Piet van Oostrum [EMAIL PROTECTED]
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4]
Private email: [EMAIL PROTECTED]
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
Am Fri, 25 Nov 2005 06:02:40 -0800 schrieb peter.mosley: I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. Yes, if you come from Visual Basic you might be missing something. I developed with Visual Basic some time ago and like some parts of it. I've found the tutorial and reference manual on the PyGtk web site, but although I've made some progress, I keep reaching points where I have insufficient background to understand them. Currently I'm stuck on dialog boxes (the code seems immensely complex for the equivalent of MsgBox(Do you really want to do this ,vbYesNo) search for yesNoDialog here: http://guettli.sourceforge.net/gthumpy/src/editMetadata.py and I haven't got it to work properly yet) and loading graphical images in anything other than their original size, but every new step brings another struggle search for scale2pixbuf in the link. Can anyone offer any suggestions as to the least painful way forwards? Only the beginning is painful. After some time you don't miss anything from Visual Basic anymore. Happy Learning, Thomas -- Thomas Güttler, http://www.thomas-guettler.de/ E-Mail: guettli (*) thomas-guettler + de Spam Catcher: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
I suggest you take a look at Qt3, much superior to Tkinter or PyGtk. With Python, you have to use PyQt bindings. [EMAIL PROTECTED] wrote: I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. I am not an experienced programmer - just someone who from time to time writes small programs for my use. Over the years I have moved from GWBASIC to QBASIC to Visual Basic, and now trying to move across to a Linux platform. Python seems to be the best compromise between the limitations of command line basic programming and the total incomprehensibility of C. Googling around it seems the best GUI is either Tkinter or PyGtk. I found a book which recommended PyGtk, as it had a graphical design option, Glade. Coming from a VB background I latched onto that and bought the book (Beginning Python, Wrox), but it was a disappointment (or more accurately a complete waste of money) - there was insufficient detail in the text. I've found the tutorial and reference manual on the PyGtk web site, but although I've made some progress, I keep reaching points where I have insufficient background to understand them. Currently I'm stuck on dialog boxes (the code seems immensely complex for the equivalent of MsgBox(Do you really want to do this ,vbYesNo) and I haven't got it to work properly yet) and loading graphical images in anything other than their original size, but every new step brings another struggle I've seen reference to a Tkinter book - something like 'Python and Tkinter Programming' but it seems to be out of print and unavailable. Can anyone offer any suggestions as to the least painful way forwards? (Email address was valid once but has long since been abandoned to spam. Please rely via newsgroup) -- http://mail.python.org/mailman/listinfo/python-list
Re: books: Dive into Python vs Beginning Python
On 11/25/05, Sebastien Douche [EMAIL PROTECTED] wrote: On 11/25/05, Franz Mueller [EMAIL PROTECTED] wrote: Hi, Hi Franz! :) which of the following books would you recommend: Dive into Python or Beginning Python: From Novice to Professional? Both are very good books but I suggest the latter because more recent. Beginning Python talk python 2.3 and 2.4 : set data structure, generator, iterator... Dive into Python actually mentions generators : http://diveintopython.org/dynamic_functions/stage6.html And it's a very well written book btw. -- http://mail.python.org/mailman/listinfo/python-list
Re: Why is dictionary.keys() a list and not a set?
Christoph Zwerschke [EMAIL PROTECTED] writes: As a general note, I think it would be good to place the exact description in a footnote, since speaking about hashable objects, __hash__ and __cmp__ will certainly frighten off newbies and make it hard to read even for experienced users. The main text may lie/simplyfy a little bit. Good point. However, since the Python docs are a reference and not a textbook or manual, I think the debt should not be payed back later, but immediately in a footnote. Ok, how about this for dictionaries/sets: Any hashable object can be used as a dictionary key (set member). Immutable objects, except for tuples that contain a non-hashable object, are hashable. Python classes are normally hashable(1). And the footnote is: Instances of Python classes are hashable if they define a __hash__ method, or if they don't define either __cmp__ or __eq__. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Antoon Pardon [EMAIL PROTECTED] writes: Op 2005-11-24, Mike Meyer schreef [EMAIL PROTECTED]: Antoon Pardon [EMAIL PROTECTED] writes: The usual response is That's not the Python way. That's not calling someone dumb, just pointing out that they don't yet fully understand the Python way. That is not the Python way, is just saying Python doesn't have it in other words. So it can't be the answer to why python can't have something. No, it isn't. At least, it isn't when I use it. A language is more than just an accumulation of features. Well, a good language is more than just an accumulation of features - there's a philosophy underlying the language, that guides what features are added and what features aren't. Other languages have other philosophies, and wind up being good for other things. But how this philosophy influences design is not straight forward. The ternary operator was thought of to go against the philosopy, By who? and now seems to be at least compatible with the philosophy. So when someone asks why it is not in python, saying It is not the python way still doesn't answer the question, because the person would probably still like to know what in his proposal is against the python philosophy and why. Sometimes, such things are easy to explain, and they'll generally get that explanation. Sometimes they aren't, so you're reduced to pointing out similar - but more obvious - things that aren't in the language, and import this, and suggesting that they try it for a while and see how it works My vision isn't perfect - I've changed my mind about things: I used to want real macros, and I initially disliked list comprehensions. My vision doesn't agree with the developers - notably including Guido's - a lot of the time. On the other hand, they haven't done anything that strikes me as so wrong that I want to spend the time required working on Python rather than in Python to allow me to get it fixed. I see nothing wrong with that. But I would apreciate it, should you be more open about something being your personal vision. To me something like: That is not the python way comes accross as: You just don't understand about python, if you ask/propose something like that That's essentially true. In some cases, the reasons can be explained without understanding about python. In some cases, they can't. It gives me the feeling the person is saying something like: Python is like this, I like it this way, so nobody better suggests this changes. You're carrying things a step to far, going from explaining an overly brief statement to imagining a motive for said statement. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Singleton and C extensions
Emmanuel Briot wrote:
I am participating in the development of a GPL IDE
https://libre2.adacore.com/gps/
I am not really good at python, but I was trying to implement the
singleton design pattern in C, so that for instance calling the constructor
ed = Editor (foo)
Fredrik's advice is probably better, but if you must:
class Editor(object):
table = {}
def __new__(klass, name):
try:
return klass.table[name]
except KeyError:
klass.table[name] = super(Singled, klass).__new__(klass)
return klass.table[name]
--Scott David Daniels
[EMAIL PROTECTED]
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
Search this group for PythonCard and wxPython for many posts on this subject. Also see the following link for descriptions of other alternatives: http://www.fredshack.com/docs/python.html bs -- http://mail.python.org/mailman/listinfo/python-list
Re: Python as Guido Intended
Antoon Pardon [EMAIL PROTECTED] writes: Well this is, is one thing I have a problem with. The python people seem to be more concerned with fighting things that could be used counter the python philosophy, than search for things that enable working in the python philosophy. And what's wrong with that? Yes. And if you need a red hammmer, you should get a red hammer, not use red spray paint on one that wasn't designed to be red. Just because *you* don't see how providing a red option violates the philosophy of python doesn't mean that it doesn't do so. Well this seems to be the main conflict between those who would like Python to go a bit further and those that oppose it. Should the priority be to enable python's philosophy or should it be the priority to limit python to only allow it's philosophy. Those two statements say the same thing. Part of the Python philosphy, from import this, is that there should only be one obvious way to do it. By enabling that part of Python's philosphy, you're automatically limiting python to not allow other - specifically non-pythonic - ways to do the same thing. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Which License Should I Use?
I've been watching the flame war about licenses with some interest. There are many motivations for those who participate in this sector, so disagreements over licenses reflect those agendas. I don't have an agenda, at least not right now. I do plan on writing a few programs. These will be tools I need for firmware testing. They will be relatively simple things like tools for breaking down data by its structure for easy viewing, sending commands/macros over serial ports, etc. Similar things exist, but they don't do everything I need. These will also be excellent learning opportunities for me, since I'm still pretty shaky on Python. How do I decide on a license? Are there any web sites that summarize the pros and cons? I guess I don't care too much about how other people use it. These things won't be comprehensive enough or have broad enough appeal that somebody will slap a new coat of paint on them and try to sell them. I guess I don't care if somebody incorporates them into something bigger. If somebody were to add features to them, it would be nice to get the code and keep the derivative work as open source, but I don't think that matters all that much to me. If somebody can add value and find a way of making money at it, I don't think I'd be too upset. I will be doing the bulk of the coding on my own time, because I need to be able to take these tools with me when I change employers. However, I'm sure that in the course of using these tools, I will need to spend time on the job debugging or tweaking them. I do not want my current employer to have any claim on my code in any way. Usually if you program on company time, that makes what you do a work for hire. I can't contaminate my code like that. Does that mean the GPL is the strongest defense in this situation? I'm open to suggestions as to which licenses to consider. However, please try to keep the conversation to the decision process or what sounds like it is best for this purpose. Let's keep the broader issue of which license will bring about the fall of Western Civilization on the other thread. Ron Britton (The gibberish on the next line really is my email address.) nk67v8o02 at sneakemail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: How to get started in GUI Programming?
[EMAIL PROTECTED] wrote: I am trying to learn GUI programming in Python, but have to confess I am finding it difficult. Googling around it seems the best GUI is either Tkinter or PyGtk. This statement is, and has been subject to much debate. If you ask 10 people on this newsgroup you'll probably get 12 opinions. If you're having trouble at this early stage, you might want to reconsider and take another look at either QT or wxWidgets. I've been through the QT tutorial and was quite satisfied with it, although I'll admit I was not a GUI newby at the time. I also found the tutorial accompanying Boa Constructor (http://boa-constructor.sourceforge.net/) to be a good start at creating a wxWidgets GUI. Bill -- http://mail.python.org/mailman/listinfo/python-list
Re: Making immutable instances
Paul Rubin http://[EMAIL PROTECTED] writes: Mike Meyer [EMAIL PROTECTED] writes: There isn't a standard serialize method in Python, so I don't know how you want to define it. I can think of perfectly reasonable definitions of serialize where obj.serialize() won't always return the same string on an immutable object, even if you don't allow adding attributes. Fair enough. How's this: a = ImmutableObject() b = deepcopy(a) assert a == b # a and b start out equal do stuff # since a and b are immutable, they should still be equal # no matter what has happened above assert a == b If you've added attributes to a but not to b, they should compare unequal, breaking immutability. Why should they compare unequal just because you add an attribute? Nothing says all attributes have to be involved in an equality comparison. In fact, Python classes by default ignore all attributes when doing an equality comparison. In order to compare attributes, you have to provide an __eq__ method (or __cmp__, but we'll ignore that). It can't mention your new attribute, because it doesn't exist unless you add it. So your final assertion will be true even after adding a new attribute. Of course, there's a fundamental flaw in your definition of immutable, in that there are immutable objects - tuples - for which the condition t1 == t2 is *not* a constant. Tuples can hold mutable objects, meaning you can change those. Doing so will make a tuple not compare equal to a copy of the state prior to changing the contents of the tuple. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Why are there no ordered dictionaries?
On Wed, 23 Nov 2005, Christoph Zwerschke wrote: Alex Martelli wrote: However, since Christoph himself just misclassified C++'s std::map as ordered (it would be sorted in this new terminology he's now introducing), it seems obvious that the terminological confusion is rife. Speaking about ordered and sorted in the context of collections is not a new terminology I am introducing, but seems to be pretty common in computer science This is quite true. I haven't seen any evidence for 'rife' misunderstanding of these terms. That said ... Perhaps Pythonists are not used to that terminology, since they use the term list for an ordered collection. An ordered dictionary is a dictionary whose keys are a (unique) list. Sometimes it is also called a sequence Maybe we should call it a 'sequenced dictionary' to fit better with pythonic terminology? tom -- YOU HAVE NO CHANCE TO ARRIVE MAKE ALTERNATIVE TRAVEL ARRANGEMENTS. -- Robin May -- http://mail.python.org/mailman/listinfo/python-list
