Re: New versions breaking extensions, etc.
Jive wrote: Why won't extensions compiled to run with 2.3 also work with 2.4? I believe nobody has answered *this* question, yet: Python extensions built for 2.3 link with python23.dll, Python extensions build for 2.4 link with python24.dll. pythonxy.dll has global variables, e.g. the pointers to True, False, None, or the dict type object. If you have two copies of the Python runtime, you get two copies of each local object. This cannot work: we really need to rely on having only one dict type, or else is comparisons with the dict type fail. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Wrapper objects
On 10 Dec 2004 15:03:01 -0800, [EMAIL PROTECTED] wrote:
Well, that could be a feature, depending on what your use case is.
Or you could make a method for adding methods, I suppose.
A perfectly transparent wrap of obj would be to do nothing ;-)
What do you actually want to do?
Actually, the very best would if only type(), isinstance() and the
is-keyword could an object and a wrapped version of it apart.
I've thought of using a weakdict instaed, problem is, it would be a
little bit too transparent for my purpose as the only way to tell an
object and a wrapped version of it apart would be by my own functions
which would do lookups in that dict. Secondly, it would only allow for
one comment per object dopy, which would fail horribly for e.g. numbers
(there are hundreds of uses of the number 1, which all needs different
comments for the number).
Here is a different approach, which I think will perform better than masses
of descriptors and delegations and individual classes, plus wrapping is
just a single assignment. See the W0, W1, W2 usage in the example below.
The idea is to clone the object's class as a subclass in a factory
(wrapperclass)
function that takes an example object plus a second argument containing
new or overriding methods and/or class variables. This add-ins argument
is just a class, and everything except what comes in an empty class
(i.e., ['__dict__', '__module__', '__weakref__', '__doc__'] ) is copied
from the dict in to the wrapper class dict, which is initialized as
a clone of the object's class dict.
wrapo.py -
# wrapo.py -- wrapperclass factory and usage examples
# 20041211 01:02:54 -- bokr
# Use at your own risk. Alpha.
def wrapperclass(obj, AddIns):
Create a (sub)class which may be assigned to obj.__class__
to change the obj instance's apparent available methods
and class variables, taking additions from a supplied
AddIns class serving as a container for methods and variables.
cdict = dict(type(obj).__dict__)
for name, value in AddIns.__dict__.items():
if name not in ['__dict__', '__module__', '__weakref__', '__doc__']:
cdict[name] = value
cname = 'Wrapped_%s_%s'%(AddIns.__name__, type(obj).__name__)
W = type(cname, (type(obj),), cdict)
return W
import time
class Wrap_one(object):
cvar = 'Wrap_one cvar'
def now(self): return 'W1: '+time.ctime()
def __repr__(self):
return 'Wrap_one %r repr:\n%s'%(self.kw, object.__repr__(self))
def __add__(self, other):
return '%r + %r'%(self,str(other))
class Wrap_two(object):
# let orig cvar alone
def now(self): return 'W2: '+time.ctime()
def __repr__(self):
return 'Wrap_two %r repr:\n%s'%(self.args, object.__repr__(self))
def __add__(self, other):
return '%r + %r'%(type(self).__name__, str(other))
def test():
class Foo(object):
cvar = 'orig Foo cvar ;-)'
def __init__(self, *args, **kw):
self.args = args
self.kw =kw
def now(self): return '(time n/a)'
def __str__(self):
return '%s %r\n %s'%(self.now(), self.cvar, repr(self))
foo = Foo(1,2,3, x=111,y=222)
W0 = type(foo)
W1 = wrapperclass(foo, Wrap_one)
W2 = wrapperclass(foo, Wrap_two)
print '--- plain foo:\n', foo
for w in (W0, W1, W2, W0):
foo.__class__ = w
print '\n %s ' % type(foo).__name__
print foo
if w!=W0: print foo + ' a %s string.'%w.__name__
bar = Foo(22,33,bar='this is bar')
for w in (W0, W1, W2, W0):
bar.__class__ = w
print '\n %s ' % type(bar).__name__
print bar
if __name__ == '__main__':
test()
-
Result:
[ 1:16] C:\pywk\clp\wrapperwrapo.py
--- plain foo:
(time n/a) 'orig Foo cvar ;-)'
__main__.Foo object at 0x00901630
Foo
(time n/a) 'orig Foo cvar ;-)'
__main__.Foo object at 0x00901630
Wrapped_Wrap_one_Foo
W1: Sat Dec 11 01:16:40 2004 'Wrap_one cvar'
Wrap_one {'y': 222, 'x': 111} repr:
__main__.Wrapped_Wrap_one_Foo object at 0x00901630
Wrap_one {'y': 222, 'x': 111} repr:
__main__.Wrapped_Wrap_one_Foo object at 0x00901630 + ' a
Wrapped_Wrap_one_Foo string.'
Wrapped_Wrap_two_Foo
W2: Sat Dec 11 01:16:40 2004 'orig Foo cvar ;-)'
Wrap_two (1, 2, 3) repr:
__main__.Wrapped_Wrap_two_Foo object at 0x00901630
'Wrapped_Wrap_two_Foo' + ' a Wrapped_Wrap_two_Foo string.'
Foo
(time n/a) 'orig Foo cvar ;-)'
__main__.Foo object at 0x00901630
Foo
(time n/a) 'orig Foo cvar ;-)'
__main__.Foo object at 0x00901390
Wrapped_Wrap_one_Foo
W1: Sat Dec 11 01:16:40 2004 'Wrap_one cvar'
Wrap_one {'bar': 'this is bar'} repr:
__main__.Wrapped_Wrap_one_Foo object at 0x00901390
Wrapped_Wrap_two_Foo
W2: Sat Dec 11 01:16:40 2004 'orig Foo cvar ;-)'
Wrap_two (22, 33) repr:
__main__
Re: GUIs: wxPython vs. Tkinter (and others)
Mike Meyer wrote: I don't know about wxPython, but PyQt includes it's own threading facility, plus hooks to talk to databases. That would of course be a great argument if Python didn't already have a threading facility, and a standard API for talking to databases with implementations for all major players. It also has a widget for creating Windows wizards for walking through a set of options. Besides the fact that wizards isn't really that great (read Cooper), if your toolkit doesn't let you create a dialogue with a couple of buttons and a swappable frame, it's not a very good toolkit. (that's very easy, in both Tkinter and wxPython. You can probably find ready-made modules on the net if you look around a little) o Is the general programming methodology pretty much the same between the two (e.g., the general program structure - using callbacks Frames, etc. is the same, it's just a question of calling different widgets with their own arguments)? Not for Qt. It has the notion of SLOTs and SIGNALs. You connect a signal from an object to a slot or signal on another (or the same) object. You can, for example, connect a signal from a slider widget to a slot on a digital display widget, thus causing the display to change as you move the slider. At the python level, slots are just callable objects. At the C++ level, slots are magic methods of objects. Signals are usually associated with GUI events, but Python can emit them for whatever reason it wants. It's possible to connect C++ signals to C++ slots/signals in Python, meaning that Python won't be involved when that signal is emitted. That's would of course be a great argument if you didn't have Python. (even if Python's slower than C++, it's a lot faster than a user). If you want bind an event source (signal) to a slot (method) in one line, use a lambda. If you need to add more behaviour (you usually do), use a function. PyQt provides a higher level of abstraction. Whan what? C++ plus a low level UI API, sure. But Tkinter+Python? wxPython+Python? You gotta be kidding. (or you're borrowing it from Trolltech's marketing material; I notice that the phrase higher level of abstraction is very popular amont Qt fans, but Trolltech themselves only seem to use it when they talk about lower-level libraries like X/Xt/Motif and the native Win32 API) I've never tried doing animation in TkInter. Qt provides timer devices that you can use to drive animations. I suspect that doing the same in TkInter would be noticably more difficult. Eh? You don't know how to do a loop in Python? Or register a callback? wxPython contains both timers and a low-level graphics API; for Tkinter, you the after facility and the Canvas; if you need lower-level drawing with tighter Python intergration, use the WCK. (for more advanced drawing, I'd recommend OpenGL, which is available for them all) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Howto Extract PNG from binary file @ 0x80?
flamesrock [EMAIL PROTECTED] wrote: As a newbie to the language, I have no idea where to start..please bare with me.. The simcity 4 savegame file has a png image stored at the hex location 0x80. What I want to extract it and create a file with the .png extension in that directory. Can somebody explain with a snippet of code how I would accomplish this? I've looked around but the information is too vague and I don't know how to start. there are *many* ways to ignore the first 128 bytes when you read a file (you can seek to the right location, you can read 128 bytes and throw them a way, you can read one byte 128 times and throw each one of them away, you can read all data and remove the first 128 bytes, etc). here's a snippet that understands the structure of the PNG, and stops copying when it reaches the end of the PNG: import struct def pngcopy(infile, outfile): # copy header header = infile.read(8) if header != \211PNG\r\n\032\n: raise IOError(not a valid PNG file) outfile.write(header) # copy chunks, until IEND while 1: chunk = infile.read(8) size, cid = struct.unpack(!l4s, chunk) outfile.write(chunk) outfile.write(infile.read(size)) outfile.write(infile.read(4)) # checksum if cid == IEND: break to use this, open the input file (the simcity file) and the output file (the png file you want to create) in binary mode, use the seek method to move to the right place in the simcity file, and call pngcopy with the two file objects. infile = open(mysimcityfile, rb) infile.seek(0x80) outfile = open(myimage.png, wb) pngcopy(infile, outfile) outfile.close() infile.close() hope this helps! /F -- http://mail.python.org/mailman/listinfo/python-list
Re: New versions breaking extensions, etc.
Jive wrote: The other issue is that the interpreter and the extensions may be linked to different versions of the Microsoft runtime. Doesn't Microsoft have an answer for that? Microsoft's answer to this question is: don't do that. Never mix different versions of the CRT in a single application. There are (at last count) nine skillion ActiveX components in the wild. Surely Microsoft didn't blast them into oblivion with dot-net -- did it? No, it didn't - but so what? The point is that ActiveX controls normally don't use the CRT in dangerous ways, since they are constrained to use Co* function calls only. I remember having trouble with that last bit once. But I seem to recall there was an easy answer. Something to do with the main ap and the DLL using the same heap or some such thing. Something like that, for sure. [require that extensions be recompiled] It would be a Good Thing to put a stop to that requirement, no? No. The maintenance cost of such a new API would be significantly higher, and Python would lose some of its attractiveness for C developers. No doubt. I don't understand what the deal is with msvcr71 and all that, You probably either need to learn what the deal is, or else you have to trust others that there is no better way. That would be good. But is using VC++ 6.0 right out? As it stands, I can no longer build extensions that will run with a standard dot-net Python 2.4 release. Or at least I don't know how. The most easy way to do this is to use VC7.1 (VS.NET 2003). That will work out of the box (you need to box first, of course). Thinking it over, I'm wondering why the Python crowd went with dot-NET in the first place. We did not go to .NET. Python 2.4 has nothing to do with .NET. It just happens that the C compiler we use ships as part of a product that has .NET in its name - the C compiler itself is Microsoft Visual C 7.1, aka Microsoft C 13.10. That compiler is now used because it has a number of improvements over Microsoft C 12.00, and because VC6 is no longer commercially available. Many developers have only VS .NET 2003 available, so if Python would continue to be built with VC6, those people could not build extensions for it - they could not even buy the compiler they needed, anymore. OTOH, people who only have VC6 just need to buy VS.NET 2003, which is still available. Or else they find out what alternative compiler arrangements can be made. Surely the world would be a better, happier place without MS jerking everyone around. It would surely be better if the operating system shipped with a compiler, so anybody could rebuild things, and you wouldn't need binary distributions in the first place :-) Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs: wxPython vs. Tkinter (and others)
Fredrik Lundh wrote: I don't know about wxPython, but PyQt includes it's own threading facility, plus hooks to talk to databases. That would of course be a great argument if Python didn't already have a threading facility, and a standard API for talking to databases with implementations for all major players. Python threading is not perfect in many cases in GUI programming -- you have to implement your own notification mechanism (eg. using queue polling), as usually you can communicate with GUI only from main application's thread. While this is the case also for Qt, QThread instances have ability to post events to any arbitrary Qt objects, thus making life a bit easier. Anyway, all of above mentioned toolkits have its own pros and cons and in most of cases choice is a matter of personal taste. -- Jarek Zgoda http://jpa.berlios.de/ | http://www.zgodowie.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: collaborative editing
Nick Craig-Wood [EMAIL PROTECTED] wrote: Robert Kern [EMAIL PROTECTED] wrote: Personally, I loathe writing at any length inside a Web browser and prefer to use a real editor at all times. Me too! You need mozex... http://mozex.mozdev.org/ Here is a good page about Wikis (from the creators of spamassassin) including stuff about Moin Moin (which is in Python) - lots of good advice for anyone thinging about a Wiki. http://taint.org/2004/09/28/191712a.html -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Raw Sockets vs. What?
Hi, I'm new to Python (1 week), but I'm writing an out-of-process debugger for a Python ide. I tried execFile first, but stuff leaked over from the wx libraries we are using. And, anyway, the next code set is PHP so this has to be tackled anyway. So, the question: How to communicate between two instances of the python interpreter? Specifically, I need to pass the api and objects from bdb, the base class for the debugger. One interpreter runs the ide, the other the debugger and client code. We were talking and just opening a socket and doing the rest from there came up. This, to me, (admitedly a java guy) seems like a lot of work. If it were just setting breakppoints and stepping, well ok. But I also want to have introspection on the debugger side objects. I could use raw sockets and write a bunch of stuff. Does anyone have a suggestion about some pythonesque way to tackle this? Many thanks in advance, Matt -- http://mail.python.org/mailman/listinfo/python-list
Re: Zip with a list comprehension
This is probably so easy that I'll be embarrassed by the answer. While enhancing and refactoring some old code, I was just changing some map()s to list comprehensions, but I couldn't see any easy way to change a zip() to a list comprehension.Should I just let those sleeping dogs lie? (list comprehensions seem more readable than map(), but if the list comprehension that does the equivalent of zip() is less expressive than zip(), I'll stick with zip()). Leave in zip(), enumerate(), and reversed(). They are meant to be used with listcomps and genexps. If you want to go the extra distance, itertools.izip() can offer a performance boost and better memory utilization than zip(). It can be used almost anywhere as long as the app doesn't demand a real list. Raymond Hettinger -- http://mail.python.org/mailman/listinfo/python-list
Re: swig Python question
It's me wrote: It's me [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I am playing around with SWING building a Python module using the no brainer example in http://www.swig.org/tutorial.html. With that first example, Oops! Soapy fingers. SWIG - not SWING. -- It's me. I have used SWIG before, and it's not always such a no-brainer. In fact, it rarely is except for trivial examples. But it can work. I think it is best suited for wrapping large libraries. For small stuff, it would be better to just do it manually using the Python C API. Good luck. -- It's not me. -- \/ \/ (O O) -- oOOo~(_)~oOOo Keith Dart [EMAIL PROTECTED] public key: ID: F3D288E4 -- http://mail.python.org/mailman/listinfo/python-list
Re: Civilization IV uses Python for scripting
In article [EMAIL PROTECTED], Carl Banks [EMAIL PROTECTED] wrote: Advancement: PYTHON Requires: Computers, Mythology Effect: * Increases revenue generated by capitalization by 300% * Makes two unhappy citizens happy * Renders all Wonders of the World in all other countries completely obsolete * Boosts production of Research Lab by 150% * Gives all military units a 200% increase in attack power, 100% increase in defense, and a tenfold increase in accuracy * Decreases corruption by 50% in every city. * Decreases the maintenance costs of the following buildings by 1: - Airport - Bank - Factory - Harbour - Hydro Plant - Mass Transit - Nuclear Plant - Power Plant - SDI Defense - Stock Exchange - University * Scientists' science output increased by 50% * Entertainers luxury output increased by 50% * Automatically decreases the morale in every city of all countries that have PERL advance but not PYTHON by 50% And of course you can build the Google Wonder! ;) -- Remove luncheon meat to reply. -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
houbahop wrote: def RAZVarAnimesDuJour(self,oSortiesAnimeTitreLabel): for i in xrange(len(oSortiesAnimeTitreLabel)): del oSortiesAnimeTitreLabel[i] it doesn't emty my var (i don't want to destroy the var, just make it like if it just have been created Other posts are missing the point somewhat, I think. While they do recommend better ways of doing what you want to do, they don't say why your function doesn't work. What exactly happens when you execute your code? When I try it, I get an exception: alist = range(5) def a(alist): for i in xrange(len(alist)): del alist[i] a(alist) Traceback (most recent call last): File pyshell#22, line 1, in -toplevel- a(alist) File pyshell#21, line 3, in a del alist[i] IndexError: list assignment index out of range What happens is this: the first time, the first element is deleted. This causes all other elements to shift: the second element becomes the first one, the third becomes the second, and so on. Or: 0, 1, 2, 3, 4 becomes 1, 2, 3, 4 The list gets shorter each time. But you're still looping over the whole length of the list, which means after some time you're accessing elements that no longer exist. One way to solve it is to loop backwards: first delete the last element, than the next to last, etc. Apart from that, it's much easier and clearer to reset the list with just alist = [] -- Codito ergo sum Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Re: New versions breaking extensions, etc.
Jive wrote: Martin v. Löwis [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] OTOH, people who only have VC6 just need to buy VS.NET 2003, which is still available. I don't even know how to do that! :-) What's the difference between VC++ .net Standard and Visual Studio .net Pro? (Besides $370?) Is the former C++ only, but with the IDE, and the later the whole shebang with SourceSafe, VBASIC, and all that? OH NO! I've gone seriously off-topic. Please don't call the Spanish Inquisiton. Allow me to re-phrase the question: What do I need to build (on-topic) Python extensions? Short answer to Jive's question: (1) free non-MS C compiler (either MinGW or Borland) (2) inner calm. I really can't understand what all the screaming and yelling is about. Windows Python is built using an MS compiler. Those extension developers who can't/won't buy the MS compiler use either the free MinGW compiler or the free Borland 5.5 compiler (or both!). Yes, you have to be careful about mixing the runtimes. An extension that tries to use a FILE * that was created by Python will crash. Using free() on a pointer that was malloc()ed by the other party isn't a bright idea either. There are adequate solutions to these problems, involving Python-supplied higher-level functions instead of C runtime functions. Otherwise, not a problem. Distutils has made the process of using MinGW and bcpp a snap. The documentation is adequate. When a new version of Python comes out, one rebuilds and tests one's extensions. So ... now there are THREE compilers that can be used instead of the one that Python's built with; what's the big deal? -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
houbahop wrote: Thank you everyone, but I still not understand why such a comon feature like passing parameters byref that is present in most serious programming languages is not possible in a clean way,here in python. I understand from this statement that Java is not a serious programming language? ;) I have the habit to never use globals as far as possible and this involve that my main function is passing some parameters by reference to subs to allow them to modify the vars. I don't see why lack of pass-by-reference would force you to use globals... class C(object): ... def __init__(self): ... self.list = [] ... def fill(self, iterable): ... self.list.extend(iterable) ... def empty(self): ... self.list = [] ... c = C() c.list [] c.fill(pow(x, 3, 29) for x in range(10)) c.list [0, 1, 8, 27, 6, 9, 13, 24, 19, 4] c.empty() c.list [] Or by globals do you mean instance variables? If you don't want any instance variables (which means you don't really want OO), you can still clear your list as long as you have any name bound to the list object: def clear(lst): ... while lst: ... lst.pop() ... x = [pow(x, 7, 19) for x in range(10)] x [0, 1, 14, 2, 6, 16, 9, 7, 8, 4] clear(x) x [] or alternatively: def clear(lst): ... lst[:] = [] ... x = [pow(x, 7, 19) for x in range(10)] x [0, 1, 14, 2, 6, 16, 9, 7, 8, 4] clear(x) x [] Note that neither of these functions requires pass-by-reference; the lst local in the function is not the same name as the x local outside the function. But since you're basically just passing a pointer by value, both variables still point to the same object (or in Python terms, both names are bound to the same object). To apply an affect that is visible to all names bound to an object, you simply need to mutate the object. In the cases above, this is just a matter of using the appropriate object method (list.pop or list.__setslice__ respectively above). Is this so bad? Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
In article [EMAIL PROTECTED], houbahop d.lapasset[Remove me)@chello.fr wrote: Thank you everyone, but I still not understand why such a comon feature like passing parameters byref that is present in most serious programming languages is not possible in a clean way,here in python. I have the habit to never use globals as far as possible and this involve that my main function is passing some parameters by reference to subs to allow them to modify the vars. I would be sad to break my structured programming scheme because a lack of feature. In others languages you can use things like pointers to strings or Mysub(byref MyVar) and it does the trick :) It isn't a problem with passing by reference. The passing-by-reference part works just fine. Putting in a print statement to trace what's actually happening: Python 2.3 (#46, Jul 29 2003, 18:54:32) [MSC v.1200 32 bit (Intel)] on win32 Type help, copyright, credits or license for more information. a = [1,2,3,4,5] def X(s): ... for i in xrange (len (s)): ... del s[i] ... print 'X:', s ... X(a) X: [2, 3, 4, 5] X: [2, 4, 5] X: [2, 4] Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 3, in X IndexError: list assignment index out of range a [2, 4] As the last line shows, lots of things got removed from `a` .. but not everything. Roel Schroeven explained why. Regards.Mel. -- http://mail.python.org/mailman/listinfo/python-list
Re: Raw Sockets vs. What?
Matt wrote: So, the question: How to communicate between two instances of the python interpreter? Specifically, I need to pass the api and objects from bdb, the base class for the debugger. One interpreter runs the ide, the other the debugger and client code. We were talking and just opening a socket and doing the rest from there came up. This, to me, (admitedly a java guy) seems like a lot of work. If it were just setting breakppoints and stepping, well ok. But I also want to have introspection on the debugger side objects. I could use raw sockets and write a bunch of stuff. Does anyone have a suggestion about some pythonesque way to tackle this? let the debugger listen to a randomly chosen local port, let the client wrapper connect back to the debugger via that port, and use a suitable marshalling layer to wrap commands and data for the introspection part. This has been done many times by many IDE developers (including yours truly). Designing the RPC API is the only tricky part here, and it doesn't have to be that tricky (some people are known to use really simply stuff, such as XML-RPC, for this purpose). Unless I'm completely mistaken, recent versions of IDLE have a remote debugger designed and implemented by GvR himself. Maybe you could use that code right out of the box? /F -- http://mail.python.org/mailman/listinfo/python-list
Re: UrlLib2 Proxy and Https
Check out the following link. It helped me achieve the same thing (access a HTTPS site via a proxy). http://groups.yahoo.com/group/linux-bangalore-programming/message/4208 Cheers, Sandeep http://sandeep.weblogs.us/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Clarification of two concepts (or maybe one?)
What you are looking for are 2 apps: 1) Something to freeze your application into something that resembles an installation like what comes on commercial applications. On Windows a popular choice is py2exe. All dependent .py, .pyd, etc. files can be included in the distribution. It also includes necessary python .dlls. 2) Something to create a distribution. On Windows a popular choice seems to be Inno Installer. It creates a single setup.exe file that can be distributed and is very flexible. Hope info helps. Larry Bates Syscon, Inc. Fredrik Lundh wrote: Eddie Parker wrote: What Im looking for, is a way to turn a python application, into a stand-alone application. i.e., you dont need the Python interpreter, libraries, etc, installed on your hard drive. (Im OK with .py files existing I just dont want to have to bother the user to install more then just my app). you cannot run Python without a Python interpreter -- but you can ship the interpreter DLL and the necessary library components with your app, and you can use bundling tools to reduce the number of files to a minimum: http://effbot.org/zone/python-compile.htm http://www.python.org/cgi-bin/moinmoin/DistributionUtilities /F -- http://mail.python.org/mailman/listinfo/python-list
Re: ElementTree and XPATH
Istvan Albert wrote: [EMAIL PROTECTED] wrote: it seems to be invalid syntax if I give /a/b[0] to the findall() method. Does anyone know the correct syntax? I think the proper mindset going in should be that elementtree does not support xpath but that there are some handy constructs that resemble the location steps of xpath. The lxml Pythonic wrapper of libxml2 which aims (among others) to build an elementtree API compatible interface will indeed extend that API and offer XPath support. Of course it's all not done yet. :) http://codespeak.net/mailman/listinfo/lxml-dev http://codespeak.net/svn/lxml/trunk/ Regards, Martijn -- http://mail.python.org/mailman/listinfo/python-list
Re: thread/queue bug
phil wrote: Well its an anomaly. I sent to bug list. Probably never see it again. I think some sort of semaphore thingy, which I know nothing about, is sneaking in under unreproducible conditions. I'm moving on. If you want to try one more thing, try mucking with a call to sys.setcheckinterval(). This used to be 10 by default but is now 100. In any case, changing it will quite often significantly change the code's behaviour in the presence of race conditions. Try values of 1 and 1000 and see if anything makes a difference. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: os.system() inside a thread problem
Daniel Bernhardt wrote: my thread calls a program with os.system(). os.system(/usr/bin/wine /path/to/ultima/online.exe) in the example you included, you use execv. which one is it? Ultima Online is starting and i can enter commands and navigate through the game with my keyboard. If I move the mouse over the Ultima Online window Ultima Online crashes. (the mouse just need to overlap 1 pixel of the egde of the window. titlebar inlcuded) /usr/bin/wine: line 55: 11675 Segmentation fault Same with os.popen() If I run os.system() outside the thread everything is working like expected. Other programs (wine emulated and nativ) work inside and outside the thread. Can anyone tell me how I can fix this? just curious: do you really have to use a thread? why not just do os.system(command + ) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: os.system() inside a thread problem
Fredrik Lundh wrote: in the example you included, you use execv. which one is it? it should be system(). I just played a bit and forgot to change it back. just curious: do you really have to use a thread? why not just do os.system(command + ) No, i don't need to use a thread. I just wanted learn something about it and thought it would be a good start. I will use os.system(command + ) as you said to solve the problem. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fun with Outlook and MAPI
At the risk of beating a dead horse, but you really should consider using SMTP instead if you are really going to be sending a lot of messages. I think you will find it more reliable and much faster. It also eliminates the need for ANY email client to be on the machine that is sending the messages. http://motion.technolust.cx/related/send_jpg.py Here is a link to a class that wraps everything up very nicely. You should be able to be sending SMTP emails with it in 10-15 minutes. It supports binary attachments as well. FYI, Larry Bates Chris wrote: I'm trying to send an e-mail through outlook. So far I've gotten it to work with the mail script at http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/149461 My only problem is that when I call Resolve() and Send(), I get confirmation dialogs. I will be sending out quite a few e-mails at a time, and would rather not have the user have to click yes for every single one. Does anyone know a workaround? I know about smtplib, but I would prefer to simply make what I have work. Thanks. Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Tibia 0.1 DOM-based website editor
Interesting. I couldn't get the demo to work either by the way. A 404 error on the tba file. This is *similar* t oa project I'm about to release, Jalopy. Jalopy is a collaborative website tool - allowing a team of people to work on a website together. It uses Kupu as an online WYSIWYG HTML editor. (I assume tibia uses something similar ? if not you should integrate Kupu !). You can see a jalopy demo at http://www.voidspace.org.uk/cgi-bin/jalopydemo/jalopy.py I'm not *sure* if that is the latest version - but I think so. I've nearly finished the docs and will do a release. Regards, Fuzzy http://www.voidspace.org.uk/atlantibots/pythonutils.html -- http://mail.python.org/mailman/listinfo/python-list
Re: your favorite quick reference? (was Python Docs. Hardcopy 2.4 Library Reference, interested?)
O'Reilly has CD bookshelves http://cdbookshelves.oreilly.com/ , combining their books on a topic into a CD, for various subjects, including Perl, but not yet for Python. I own the paper copies of several of their Python books. A single CD containing their books Jython Essentials Learning Python, 2nd Edition Programming Python, 2nd Edition Python XML Python Cookbook Python in a Nutshell Python Pocket Reference, 2nd Edition Python Programming on Win32 Python Standard Library would be a great purchase, especially if upgrade prices were available when new editions of books like Python in a Nutshell were released, to keep up with changes in the language. I wonder who at O'Reilly can be contacted to lobby for this. -- http://mail.python.org/mailman/listinfo/python-list
Re: building python extensions with .net sdk compiler?
David Fraser wrote: So using MinGW seems like the better option ... is it working for Python 2.4? Yes it does. :) I haven't tried it, but probably. The problem with the toolkit is that mscvccompiler.py in distutils is expecting VisualStudio to be installed, not the toolkit. So when it goes to lookup paths to the installed tools, it doesn't find them. All that's actually needed to make it work (After installing all 4 required packages) is to add several strings to your registry. You'll probably have to add all the keys below \Software\Microsoft as well. Under : HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\7.1\VC\VC_OBJECTS_PLATFORM_INFO\Win32\Directories You need to add the strings: Include Dirs(path to toolkit \include; path to platform sdk \include) Library Dirs(path to toolkit \lib; path to platform sdk \lib) Path Dirs (path to toolkit \bin; path to platform sdk \bin) And it'll be happy. Of course it'd be nice if msvccompiler.py just fell back to looking for the toolkit/sdk default dirs (or looked them up via environment vars, since the toolkit does include a vcvars32.bat that sets appropriate ones) if the VS lookup failed. -- http://mail.python.org/mailman/listinfo/python-list
RE: Tibia 0.1 DOM-based website editor
Fuzzyman wrote: Interesting. I couldn't get the demo to work either by the way. A 404 error on the tba file. Bah. You must've looked after I switched fom .tba to .py Try http://www.aminus.org/rbre/tibia/demo/tibia.py This is *similar* t oa project I'm about to release, Jalopy. Jalopy is a collaborative website tool - allowing a team of people to work on a website together. It uses Kupu as an online WYSIWYG HTML editor. (I assume tibia uses something similar ? if not you should integrate Kupu !). Similar, but with important differences. Although Tibia makes use of Javascript to manipulate the DOM, its goals and audience are different. Tibia: 1. ...is a single file, to reduce deployment cost: download (wget), edit httpd.conf or IIS conf (if you're not already mapping .py to CGI), write a tibia.conf if you don't want the defaults. Install PIL if desired, which is a one-liner on Debian and an installer on Win*. So Kupu's right out. So is the jalopy approach: login_tools, configobj, caseless, listquote, dateutils, dataenc, pathutils and cgiutils is far too many dependencies when you're shooting for zero/one ;). 2. ...combines *both* WYSIWYG and source code access, at the same time. Your typing is performed in a plain-'ol textarea, which avoids all of the where is my cursor? problems with WYSIWYG-only when used on complex pages. However, as you type, your changes are reflected in real time in the source document. I need an Undo button, though. /pops off and adds a new feature request 3. ...handles complex, preexistent web pages produced by others. Have your web page laid out by a pro, then give access to individual elements to your content providers as needed. Using the web grabber and upload tools, you can stop FTP'ing web pages to your colo completely. It doesn't appear to me from the Kupu demos that they can handle anything complex...but I could be wrong. I'd like to see a page like Plone's home page being edited by Kupu. You can see it in Tibia at the demo: http://www.aminus.org/rbre/tibia/demo/tibia.py?page=www.plone.org.html You can see a jalopy demo at http://www.voidspace.org.uk/cgi-bin/jalopydemo/jalopy.py I'm not *sure* if that is the latest version - but I think so. I've nearly finished the docs and will do a release. It looks good! I like some of the tools Kupu provides (and in fact, stole the idea for my simplistic B, I, U buttons after seeing Kupu for the first time a few weeks ago). I'm a bit unclear on exactly where Kupu stops and Jalopy starts, though. You might want to make that more clear in the help file...maybe a one-liner like Kupu does X, Y, and Z, and Jalopy adds A, B, and C. I'm looking forward to your release (with uploads! ;). Robert Brewer MIS Amor Ministries [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: New versions breaking extensions, etc.
On the other hand, it can be annoying. I can't use Python 2.4 right now because NumPy won't run. So, I need to wait for NumPy to get updated. Of course, one would say: but NumPy is open source, go build it yourself. My answer is simple: If there are more then 24 hours to a day, I definitely would... -- It's me John Machin [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Jive wrote: Martin v. Löwis [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] OTOH, people who only have VC6 just need to buy VS.NET 2003, which is still available. I don't even know how to do that! :-) What's the difference between VC++ .net Standard and Visual Studio .net Pro? (Besides $370?) Is the former C++ only, but with the IDE, and the later the whole shebang with SourceSafe, VBASIC, and all that? OH NO! I've gone seriously off-topic. Please don't call the Spanish Inquisiton. Allow me to re-phrase the question: What do I need to build (on-topic) Python extensions? Short answer to Jive's question: (1) free non-MS C compiler (either MinGW or Borland) (2) inner calm. I really can't understand what all the screaming and yelling is about. Windows Python is built using an MS compiler. Those extension developers who can't/won't buy the MS compiler use either the free MinGW compiler or the free Borland 5.5 compiler (or both!). Yes, you have to be careful about mixing the runtimes. An extension that tries to use a FILE * that was created by Python will crash. Using free() on a pointer that was malloc()ed by the other party isn't a bright idea either. There are adequate solutions to these problems, involving Python-supplied higher-level functions instead of C runtime functions. Otherwise, not a problem. Distutils has made the process of using MinGW and bcpp a snap. The documentation is adequate. When a new version of Python comes out, one rebuilds and tests one's extensions. So ... now there are THREE compilers that can be used instead of the one that Python's built with; what's the big deal? -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs: wxPython vs. Tkinter (and others)
Jarek Zgoda wrote: Fredrik Lundh wrote: I don't know about wxPython, but PyQt includes it's own threading facility, plus hooks to talk to databases. That would of course be a great argument if Python didn't already have a threading facility, and a standard API for talking to databases with implementations for all major players. Python threading is not perfect in many cases in GUI programming -- you have to implement your own notification mechanism (eg. using queue polling), as usually you can communicate with GUI only from main application's thread. With wxPython, PostEvent (which is what CallAfter also uses) is threadsafe and can be used from any thread, allowing you to communicate (in this direction, at least) with the GUI thread from any regular Python thread. No need for special threads provided by the framework and, in fact, even though wxWidgets (on which wxPython is built) provides a wxThread class, it is not exposed in wxPython because it is redundant there. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: building python extensions with .net sdk compiler?
Grumman wrote: David Fraser wrote: So using MinGW seems like the better option ... is it working for Python 2.4? ... Of course it'd be nice if msvccompiler.py just fell back to looking for the toolkit/sdk default dirs (or looked them up via environment vars, since the toolkit does include a vcvars32.bat that sets appropriate ones) if the VS lookup failed. Which is what the patch here: http://www.vrplumber.com/programming/mstoolkit/ does. Have fun, Mike Mike C. Fletcher Designer, VR Plumber, Coder http://www.vrplumber.com http://blog.vrplumber.com -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
houbahop wrote: Passing a pointer by value appears to me as passing a var by reference. Well, at least in the PL literature, there's a subtle difference. If Python supported pass-by-reference, you could do something like: def clear(byref lst): ... lst = [] ... x = [pow(x, 11, 17) for x in range(10)] clear(x) x [] Passing a variable by reference means that the *variable* in the function is the same *variable* as outside the function. Notice that this is not the same thing as saying that the variable in the function is a pointer to the same object as the variable outside the function. Python doesn't support pass-by-reference in this standard use of the term. But Python is basically *only* passing pointers around; there is no way to do anything else. So if passing a pointer by value is sufficient for your purposes then you won't have any problems with Python, because this is what it always does. =) Thanks I will try all of that, but what does really means mutating in python? It's the first time I hear this word in programming :)) The term is used most commonly in the pair accessor/mutator, also known as getter/setter. In general, a mutator is just a method of an object that changes that object's state. In Python, assignment does not invoke a method of an object; it binds a name to an object. For this reason, code like: def clear(lst): lst = [] # binds the name lst to a new value, [] # ignoring previous value will not change the list because it is not calling methods of the list object to change it. It will instead rebind the local name lst to a new object, []. This does not change the previous object that was associated with lst and so if you have another variable bound to the previous value (x in my examples), it will still retain the old, unchanged object. So, while assignment does not invoke a method of an object, many other things in Python do, and all of these things will appropriately modify the state of the object. For example: def clear(lst): lst[:] = [] # implicitly calls the setter/mutator list.__setslice__ def clear(lst): while lst: # implicitly calls the getter/accessor len(lst) lst.pop() # explicit call to setter/mutator list.pop # don't use this; it's inefficient, I'm just using it as an example # of using a different setter/mutator def clear(lst): while lst:# implicitly calls the getter/accessor len(lst) last_item = lst[-1] # implicitly calls the getter/accessor # list.__getitem__ lst.remove(last_item) # explicitly calls setter/mutator # list.remove Note that all of these functions will successfully clear the list because they mutate the object itself, instead of simply rebinding a name that at one point had been associated with the object. HTH, STeve -- http://mail.python.org/mailman/listinfo/python-list
Re: MP3 - VBR - Frame length in time
JanC [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Dmitry Borisov schreef: It has something to deal with the VBR tags( XING header ). *If* there is a VBR tag (it's a custom extension) and *if* that VBR tag contains a correct value. -- JanC Be strict when sending and tolerant when receiving. RFC 1958 - Architectural Principles of the Internet - section 3.9 mmpython will help but not always. Lets put it this way. I will ALWAYS read through the whole file. In that order I don't mind evaluating each frame. The thing I don't seem to be able to find is the timelength-constants for frames for the different mp3 versions, bitrates and layers. Can anybody help me? Thnaks, Ivo -- http://mail.python.org/mailman/listinfo/python-list
Re: New versions breaking extensions, etc.
It's me wrote: My answer is simple: If there are more then 24 hours to a day, I definitely would... Can we get a patch in for this? datetime.timedelta(hours=24) + datetime.timedelta(hours=1) datetime.timedelta(1) would be much preferable to the current: datetime.timedelta(hours=24) + datetime.timedelta(hours=1) datetime.timedelta(1, 3600) ;) Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
houbahop wrote:
Hello again everyone ,
var2[:]=[] has solved my problem, and I don't understand why it is
programming by side effect.
I don't think it's bad, look at this, it's what I've done :
def Clear(lvar)
lvar[:]=[]
def main (starting class)
var1=[]
var1.append('a')
Clear(var1)
From http://en.wikipedia.org/wiki/Side-effect_(computer_science)
In computer science, a side-effect is a property of a programming
language function that it modifies some state other than its return value.
Given this definition, I think you're fine -- clearing the list isn't a
side effect of the function; it is the purpose of the function. Hence
the function has no return value.[1]
Of course, in this simple case, I wouldn't be likely to write the clear
function since the inline code is simpler and has less overhead:
def main()
var1 = []
var1.append('a')
var1[:] = []
or, since in this case, you only care about var1, you can just rebind it
(and let Python garbage-collect the old list):
def main()
var1 = []
var1.append('a')
var1 = []
Steve
[1] Technically, all Python functions without a return statement return
None, but for our purposes, we can consider a function like this to have
no return value.
--
http://mail.python.org/mailman/listinfo/python-list
Re: thread/queue bug
On Fri, 10 Dec 2004 16:18:51 -0600, phil [EMAIL PROTECTED] wrote:
And sorry I got ticked, frustrating week
threading problems can do that ;-)
You are obviusly deeper into this than I can get from a cursory scan,
but I'll make some general debugging comments ;-)
And I could help more, being fairly experienced with
threading issues and race conditions and such, but
as I tried to indicate in the first place, you've
provided next to no useful (IMHO) information to
let anyone help you more than this
This is about 5% of the code.
Uses no locks.
I am mystified, I have written probably 100,000 lines
of Python and never seen a thread just lock up and quit
running. It happens on a Queue() statement so my suspicion
is a bug. ??
Or a once-in-a-blue-moon resource access deadlock of some kind?
I have kludged around it by putting all the thread/queue stuff
in the main program and import the stuff I don't want to
distribute. But mysteries haunt your dreams, sooo...
#!/usr/local/bin/python
# pnetx.py
from threading import *
from time import *
from Queue import Queue
from socket import *
Do you really need to import * ? Though the above should be safe import-wise
you are setting yourself up for name-clash problems by putting so many in
the same space. E.g., if something happened to match a misspelling typo in
your program, you wouldn't get a name error exception. Etc., etc.
One of the first rules of debugging is to eliminate the unnecessary ;-)
At least there doesn't seem to be name clashes between the above (except
starting with '_' which shouldn't get imported with *
d = {}
for imp in 'threading time Queue socket'.split():
...m = __import__(imp)
...for name in m.__dict__.keys():
...d.setdefault(name, []).append(imp)
...
for k,v in d.items():
... if len(v)!=1: print k,v
...
_sleep ['threading', 'Queue']
__file__ ['threading', 'Queue', 'socket']
__all__ ['threading', 'Queue', 'socket']
__builtins__ ['threading', 'Queue', 'socket']
__name__ ['threading', 'time', 'Queue', 'socket']
_time ['threading', 'Queue']
__doc__ ['threading', 'time', 'Queue', 'socket']
Just verifying an assumption ;-)
OTOH, do you really need (ignoring wid and name and the first content of dir()):
dir()
['__builtins__', '__doc__', '__name__']
from threading import *
from time import *
from Queue import *
from socket import *
wid = 0
for name in dir():
... print repr(name),
... wid += len(repr(name))+1
... if wid60:
... print
... wid = 0
...
'AF_APPLETALK' 'AF_INET' 'AF_IPX' 'AF_UNSPEC' 'AI_ADDRCONFIG'
'AI_ALL' 'AI_CANONNAME' 'AI_DEFAULT' 'AI_MASK' 'AI_NUMERICHOST'
'AI_PASSIVE' 'AI_V4MAPPED' 'AI_V4MAPPED_CFG' 'BoundedSemaphore'
'CAPI' 'Condition' 'EAI_ADDRFAMILY' 'EAI_AGAIN' 'EAI_BADFLAGS'
'EAI_BADHINTS' 'EAI_FAIL' 'EAI_FAMILY' 'EAI_MAX' 'EAI_MEMORY'
'EAI_NODATA' 'EAI_NONAME' 'EAI_PROTOCOL' 'EAI_SERVICE' 'EAI_SOCKTYPE'
'EAI_SYSTEM' 'Empty' 'Event' 'Full' 'INADDR_ALLHOSTS_GROUP' 'INADDR_ANY'
'INADDR_BROADCAST' 'INADDR_LOOPBACK' 'INADDR_MAX_LOCAL_GROUP'
'INADDR_NONE' 'INADDR_UNSPEC_GROUP' 'IPPORT_RESERVED' 'IPPORT_USERRESERVED'
'IPPROTO_GGP' 'IPPROTO_ICMP' 'IPPROTO_IDP' 'IPPROTO_IGMP' 'IPPROTO_IP'
'IPPROTO_MAX' 'IPPROTO_ND' 'IPPROTO_PUP' 'IPPROTO_RAW' 'IPPROTO_TCP'
'IPPROTO_UDP' 'IP_ADD_MEMBERSHIP' 'IP_DEFAULT_MULTICAST_LOOP'
'IP_DEFAULT_MULTICAST_TTL' 'IP_DROP_MEMBERSHIP' 'IP_MAX_MEMBERSHIPS'
'IP_MULTICAST_IF' 'IP_MULTICAST_LOOP' 'IP_MULTICAST_TTL' 'IP_OPTIONS'
'IP_TOS' 'IP_TTL' 'Lock' 'MSG_DONTROUTE' 'MSG_OOB' 'MSG_PEEK'
'NI_DGRAM' 'NI_MAXHOST' 'NI_MAXSERV' 'NI_NAMEREQD' 'NI_NOFQDN'
'NI_NUMERICHOST' 'NI_NUMERICSERV' 'Queue' 'RAND_add' 'RAND_egd'
'RAND_status' 'RLock' 'SOCK_DGRAM' 'SOCK_RAW' 'SOCK_RDM' 'SOCK_SEQPACKET'
'SOCK_STREAM' 'SOL_IP' 'SOL_SOCKET' 'SOL_TCP' 'SOL_UDP' 'SOMAXCONN'
'SO_ACCEPTCONN' 'SO_BROADCAST' 'SO_DEBUG' 'SO_DONTROUTE' 'SO_ERROR'
'SO_KEEPALIVE' 'SO_LINGER' 'SO_OOBINLINE' 'SO_RCVBUF' 'SO_RCVLOWAT'
'SO_RCVTIMEO' 'SO_REUSEADDR' 'SO_SNDBUF' 'SO_SNDLOWAT' 'SO_SNDTIMEO'
'SO_TYPE' 'SO_USELOOPBACK' 'SSLType' 'SSL_ERROR_EOF'
'SSL_ERROR_INVALID_ERROR_CODE'
'SSL_ERROR_SSL' 'SSL_ERROR_SYSCALL' 'SSL_ERROR_WANT_CONNECT'
'SSL_ERROR_WANT_READ' 'SSL_ERROR_WANT_WRITE' 'SSL_ERROR_WANT_X509_LOOKUP'
'SSL_ERROR_ZERO_RETURN' 'Semaphore' 'SocketType' 'TCP_NODELAY'
'Thread' 'Timer' '__builtins__' '__doc__' '__name__' 'accept2dyear'
'activeCount' 'altzone' 'asctime' 'clock' 'ctime' 'currentThread'
'daylight' 'enumerate' 'error' 'errorTab' 'gaierror' 'getaddrinfo'
'getdefaulttimeout' 'getfqdn' 'gethostbyaddr' 'gethostbyname'
'gethostbyname_ex' 'gethostname' 'getnameinfo' 'getprotobyname'
'getservbyname' 'gmtime' 'has_ipv6' 'herror' 'htonl' 'htons'
'inet_aton' 'inet_ntoa' 'localtime' 'mktime' 'ntohl' 'ntohs'
'setdefaulttimeout' 'setprofile' 'settrace' 'sleep' 'socket'
'ssl' 'sslerror' 'strftime' 'strptime' 'struct_time' 'time' 'timeout'
'timezone' 'tzname' 'wid'
(Hm, should have pre-tested wid+len(current) to
Re: New versions breaking extensions, etc.
On Sat, 11 Dec 2004 01:28:45 -0600, Mike Meyer wrote: Actually, there's a problem on Unix that may not exist on Windows. Python is installed in PREFIX/lib/pythonversion/. This lets us have multiple versions of Python installed at the same time, which is a good thing. ... The real solution is... Interestingly, I saw you going somewhere else for this. I expected, The real solution is, at least for the pure Python packages, a system-wide directory for those, reserving site-packages for things that are truly version specific. I'm not sure I'm ready to propose this yet, but thoughts? Bad idea, good idea? Obviously it isn't perfect, but it seems to me that reverse compatibility has been good enough for a while now that the imperfections are minor in impact... -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
Thank you Steven,
The funny thing is that I have taken a look at wikipedia just before to be
sure that I wasn't wrong :D
I agree with you about not making a clear function to just put what I've put
in my sample, but
this sample was more simple that what I really need for explaining purpose.
In reality My clear function is cleaning a dozen of arrays and since I need
to call it several time I have made a function of it.
a few days ago I was trying python for the little script I'm working on and
this language is more powerfull that I was thinking and very pleasant to
code.
I believe I will use it more in the future.
Dominique.
Steven Bethard [EMAIL PROTECTED] a écrit dans le message de news:
[EMAIL PROTECTED]
houbahop wrote:
Hello again everyone ,
var2[:]=[] has solved my problem, and I don't understand why it is
programming by side effect.
I don't think it's bad, look at this, it's what I've done :
def Clear(lvar)
lvar[:]=[]
def main (starting class)
var1=[]
var1.append('a')
Clear(var1)
From http://en.wikipedia.org/wiki/Side-effect_(computer_science)
In computer science, a side-effect is a property of a programming language
function that it modifies some state other than its return value.
Given this definition, I think you're fine -- clearing the list isn't a
side effect of the function; it is the purpose of the function. Hence the
function has no return value.[1]
Of course, in this simple case, I wouldn't be likely to write the clear
function since the inline code is simpler and has less overhead:
def main()
var1 = []
var1.append('a')
var1[:] = []
or, since in this case, you only care about var1, you can just rebind it
(and let Python garbage-collect the old list):
def main()
var1 = []
var1.append('a')
var1 = []
Steve
[1] Technically, all Python functions without a return statement return
None, but for our purposes, we can consider a function like this to have
no return value.
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to remove packages - wxPython
Peter wrote: Linux kernel 2.6.9 Slackware 10 Python version 2.3.4 wxPython version 2.4.2.4 I compiled and installed wxPython. There is no uninstall script that I can find for the py components. The library component has a make uninstall. What is the proper way to uninstall packages? I searched everywhere, but there seems to be no clearcut explanation. Can I just remove the site-package directories it created? Or is there a central config file for python? Generally speaking, just removing the subfolder(s) from site-packages will completely remove an extension. Some few extensions will also create a .pth file in the site-packages folder, so check for that as well. No doubt there are exceptions, but I believe this will cover 95% of the cases. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Fun with Outlook and MAPI
Chris [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] My only problem is that when I call Resolve() and Send(), I get confirmation dialogs. I will be sending out quite a few e-mails at a time, and would rather not have the user have to click yes for every single one. Here is an simple workaround: http://www.contextmagic.com/express-clickyes/ If you have win32all installed, you can even use the programming API they present to turn on and off the clickyes functionality. Roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs. Perl
[EMAIL PROTECTED] wrote: Christopher De Vries wrote: Roy Smith already touched on regular expressions, but as far as features go, I would say that the real difference between python and perl is not in the features, but in the philosophy. To help aid in this discussion, the following Python and Perl philosophy links might be useful: http://c2.com/cgi/wiki?PythonPhilosophy http://www.maths.adelaide.edu.au/~cmc/tutorials/perlintro/x175.html Now, so that I don't start another Python vs. Perl flamewar, I'd like to inform everyone that I'm about to make a few generalizations based on my experience. As should be understood implicitly, one man's experience is not the experience of everyone... As a user of both languages, I've found that what Perl and Python programmers have in common is that they were looking for a better tool when they stumbled across their language of choice... After all, one can be productive in both languages. What I've also noticed that people who use Perl tended to start using it as a way to make either C or shell scripting tasks easier (after all, this is Perl's original intended audience). Many of these developers have gone on to use Perl for bigger and better things, but without a lot of discipline (use strict, and a lot of work with the Exporter), Perl doesn't scale very well to large projects. My belief is that Perl's strength (TMTOWTDI) is also it's greatest weakness. I've also noticed that Python programmers tend to be a more diverse lot. While Guido originally intended Python to be a second language for C/C++ developers, it is also quite useful as a first language. Python's philosophy is more that there should a clear understandable way to do things, and that readability counts. That is not to say you can't perform tasks in multiple ways, it is just to say that Python doesn't believe in TMTOWTDI as Perl does. So the bottom line is this. In choosing Perl or Python, the real difference should be your mindset, and what you intend to use it for. If you want a multiparadigm programming language that offers wonderful OO support, is easy to learn, and in which you will naturally write maintainable code, choose Python. On the other hand, if you are looking for a language to text-processing and to perform short quick shell scripting like tasks, choose Perl. While both languages can be used to perform both sets of tasks, my belief is that one should pair a language and a task by strengths rather than what can be done in each language. I hope this helps! Michael Loritsch Thank you all for your input. Please feel free to keep this discussion going. I intend to use a scripting language for GUI development and front end code for my simulations in C. I want a language that can support SQL, Sockets, File I/O, and shell interaction. I welcome any opinions on this. -- http://mail.python.org/mailman/listinfo/python-list
Re: thread/queue bug
phil wrote: And sorry I got ticked, frustrating week And I could help more, being fairly experienced with threading issues and race conditions and such, but as I tried to indicate in the first place, you've provided next to no useful (IMHO) information to let anyone help you more than this This is about 5% of the code. Uses no locks. A lock is acquired in Queue.__init__(). I am mystified, I have written probably 100,000 lines of Python and never seen a thread just lock up and quit running. It happens on a Queue() statement so my suspicion is a bug. ?? I have kludged around it by putting all the thread/queue stuff in the main program and import the stuff I don't want to distribute. But mysteries haunt your dreams, sooo... What I believe to be a minimal example: freeze.py import Queue import threading import time q = Queue.Queue(4) def proc(): while True: q.get(1) Queue.Queue() print YADDA threading.Thread(target=proc).start() while True: print yadda q.put(None) time.sleep(1) /freeze.py freezemain.py import freeze /freezemain.py Invoking freezemain.py produces yadda yadda yadda yadda yadda yadda i. e. consistently q.maxsize + 2. One item about to be put, one already taken before Queue.Queue(). Deferring execution of the module-level code until after the import nofreeze.py import Queue import threading import time q = Queue.Queue(4) def proc(): while True: q.get(1) Queue.Queue() print YADDA def start(): threading.Thread(target=proc).start() while True: print yadda q.put(None) time.sleep(1) /nofreeze.py nofreezemain.py import nofreeze nofreeze.start() /nofreezemain.py and invoking nofreezemain.py produces yadda YADDA yadda YADDA yadda YADDA yadda YADDA apparently ad infinitum. Conclusion? None so far, though you might welcome the confirmation that this is not a once in a blue moon accident as Bengt Richter surmised. Import _is_ a sensitive phase... As an experiment I moved try: import thread except ImportError: import dummy_thread as thread from the Queue.Queue.__init__() method to the module body -- and now freezemain.py seems to work, too. So that would be an easy remedy, but sure there is a reason why that import statement is in such an unusual place? Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Fun with Outlook and MAPI
Larry Bates [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] At the risk of beating a dead horse, but you really should consider using SMTP instead if you are really going to be sending a lot of messages. The problem is that doesn't work in more complicated configurations such as when authentication and/or SSL have to happen, not to mention the issue of configuring servers and ports, that users have already configured in their mail clients. Additionally when you use MAPI, messages that you send also end up in your sent items folder. (I also have not had any issue sending lots of messages using MAPI). Ultimately the utility of vanilla of pure SMTP will depend on customer requirements and how simple the configuration is. Roger -- http://mail.python.org/mailman/listinfo/python-list
Re: uptime for Win XP?
Tom Wesley wrote: Esmail Bonakdarian wrote: Hi, Is there a way to display how long a Win XP system has been up? Somewhat analogous to the *nix uptime command. Thanks, Esmail I believe that uptime works from the console, but don't have a machine to check it with... Doesn't work for me, but if you have win32all installed, you can get it from Python: import win32api print Uptime:, win32api.GetTickCount(), Milliseconds Uptime: 148699875 Milliseconds hth greg -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
Dennis Lee Bieber [EMAIL PROTECTED] a écrit dans le message de news: [EMAIL PROTECTED] On Sat, 11 Dec 2004 12:43:01 GMT, houbahop d.lapasset[Remove me)@chello.fr declaimed the following in comp.lang.python: Thank you everyone, but I still not understand why such a comon feature like passing parameters byref that is present in most serious programming languages is not possible in a clean way,here in python. Well, in C, everything is also passed by value. The programmer has to explicitly pass an address as the value instead of the actual value if they want to change the contents. And, of course, the function has to know that it is an address, and explicitly dereference the address to gain access to the actual content value. Using my overworked and not quite complete example... Hello and thank you, To be honnest I must take a moment and translate your example into french to really understand it (but I believe it's very well explained :) and I will understand) I remember at school when an unix teacher was explaining what was an UID and a GID, like if the files were two persons talking and asking each other what's your UID?, we got the same, so, what is your GID ?, and I never had problems with UID and GID since that :D I have thinked to try to return an array of values like a function does (instead of passing many params to a sub) but didn't take the time to do it. I believe that programming in python involves to learn a kind of new phillosophy, new words too. as an exemple of this, for me a 'tuple' is related to database stuff. What I call an array seems to be called a list in python (C programmers use the word 'matrix' when talking of a two dimentionnal array, and 'vector' when talking of a one dimention array...sorry, a list :D ). Regards, Dominique. -- http://mail.python.org/mailman/listinfo/python-list
Re: from vb6 to Python
Hi, I have used VB6 a lot too and Python appears to me as a good alternative to .net too, but the thing that will do the difference is the GUI... I hope the ones for Python are beautifull enough as appearence is an important thing to me in softwares. D. MarcoL [EMAIL PROTECTED] a écrit dans le message de news: [EMAIL PROTECTED] Hello, I am a VB6 programmer and I would like to learn a new high level language (instead of restarting from scratch with .NET), wich is opensource and cross-platform, in order to develop cross-platform business applications I think Python is the most suitable language for the scope. My question are: - Which version of python is more suitable for creating cross-platform GUI's? I've herard of PyGTK, wxPython, PyQT, tk, Anygui.. - What is the best IDE/RAD for Python (written in Python and OpenSource) - Does exist a tool (written in Python and OpenSource) like Crystal Report for creating business reports? - Does exist a tool (written in Python and OpenSource) for makeing tables, view, querys, relation of a database and generate the SQL script? - Is it possible, from Python, to work with sqlite? And with MsAccess? Thanks for your patience and your help. Marco. -- http://mail.python.org/mailman/listinfo/python-list
Re: thread/queue bug
[Peter Otten] What I believe to be a minimal example: freeze.py import Queue import threading import time q = Queue.Queue(4) def proc(): while True: q.get(1) Queue.Queue() print YADDA threading.Thread(target=proc).start() while True: print yadda q.put(None) time.sleep(1) /freeze.py freezemain.py import freeze /freezemain.py CPython has an internal, reentrant import lock. When a thread does an import, it acquires this lock, and the lock remains held until that import is complete. As a consequence, no *other* thread can do an import (it blocks waiting to obtain the internal import lock) until the original import completes. So until import freeze returns in the main thread, no other thread can do an import. Partly for that reason, it's generally a Horrible Idea to start a thread as a side effect of importing a module. That's what freeze.py does, and you get the expected deadlock as a result. The main thread is hung waiting for import freeze to return, and the spawned thread is hung at an import in Queue.__init__() waiting for the main thread to release the import lock. Invoking freezemain.py produces yadda yadda yadda yadda yadda yadda i. e. consistently q.maxsize + 2. One item about to be put, one already taken before Queue.Queue(). Deferring execution of the module-level code until after the import nofreeze.py import Queue import threading import time q = Queue.Queue(4) def proc(): while True: q.get(1) Queue.Queue() print YADDA def start(): threading.Thread(target=proc).start() while True: print yadda q.put(None) time.sleep(1) /nofreeze.py nofreezemain.py import nofreeze nofreeze.start() /nofreezemain.py and invoking nofreezemain.py produces yadda YADDA yadda YADDA yadda YADDA yadda YADDA apparently ad infinitum. Right. Note that this is the same reason threaded tests in Python's standard regression suite define a 'test_main()' function, called by the regrtest.py driver after import of the test's module completes. It's generally suicidal to start a thread as a side effect of an import. ... Import _is_ a sensitive phase... It's quite easy to avoid thread problems in imports: never start a thread as a side effect of importing, and you'll never get a deadlock due to importing. As an experiment I moved try: import thread except ImportError: import dummy_thread as thread from the Queue.Queue.__init__() method to the module body -- and now freezemain.py seems to work, too. So that would be an easy remedy, but sure there is a reason why that import statement is in such an unusual place? I think you'd have to ask Brett (who did most of the work on dummy_thread and dummy_threading). It doesn't really matter, though: it's a general truth that starting a thread as a side effect of importing is a recipe for deadlock, and hacking specific methods and functions to avoid imports just moves the problem around. It's not a goal that anything in the standard Python library cater to bad thread practice here (the bad thread practice being, again, starting a thread as a side effect of importing). -- http://mail.python.org/mailman/listinfo/python-list
character encoding conversion
Here's what I'm trying to do: - scrape some html content from various sources The issue I'm running to: - some of the sources have incorrectly encoded characters... for example, cp1252 curly quotes that were likely the result of the author copying and pasting content from Word I've searched and read for many hours, but have not found a solution for handling the case where the page author does not use the character encoding that they have specified. Things I have tried include encode()/decode(), and replacement lookup tables (i.e. something like http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/116158ad706dc7c1/11991de6ced3406b?q=python+html+parser+cp1252_done=%2Fgroups%3Fq%3Dpython+html+parser+cp1252%26qt_s%3DSearch+Groups%26_doneTitle=Back+to+Searchd#11991de6ced3406b ) . However, I am still unable to convert the characters to something meaningful. In the case of the lookup table, this failed as all of the imporoperly encoded characters were returning as ? rather than their original encoding. I'm using urllib and htmllib to open, read, and parse the html fragments, Python 2.3 on OS X 10.3 Any ideas or pointers would be greatly appreciated. -Dylan Schiemann http://www.dylanschiemann.com/ -- http://mail.python.org/mailman/listinfo/python-list
Hashes
Hi, Are there hashes in Python? Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: uptime for Win XP?
Tom Wesley wrote: Esmail Bonakdarian wrote: Is there a way to display how long a Win XP system has been up? Somewhat analogous to the *nix uptime command. I believe that uptime works from the console, but don't have a machine to check it with... Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp. c:\uptime 'uptime' is not recognized as an internal or external command, operable program or batch file. Not here, at any rate. Maybe it's part of the Productivity Kit thingy? -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Hashes
Michael McGarry wrote: Are there hashes in Python? Define hash. Or look at Python's 'dict' type, or the hash() function and decide for yourself if that's what you meant. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: building python extensions with .net sdk compiler?
Mike C. Fletcher wrote: Grumman wrote: Of course it'd be nice if msvccompiler.py just fell back to looking for the toolkit/sdk default dirs (or looked them up via environment vars, since the toolkit does include a vcvars32.bat that sets appropriate ones) if the VS lookup failed. Which is what the patch here: http://www.vrplumber.com/programming/mstoolkit/ does. Looks like you beat me to it. :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Hashes
Peter Hansen wrote: Michael McGarry wrote: Are there hashes in Python? Define hash. Or look at Python's 'dict' type, or the hash() function and decide for yourself if that's what you meant. -Peter Yes, I guess the dict type is what I am looking for. Thank you, Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrade woes: Numeric, gnuplot, and Python 2.4
Jive wrote: 4) Buy a copy of the VC++ 7.1 and port Numeric myself. (I still don't know what to buy from Mr. Gates -- VC++ .net Standard?) VC++ 7.1, the compiler/linker, is a free download. Google for VC toolkit. You won't get the fancy IDE and stuff, but you have everything you need to build your extensions. I saw patches floating around to build Python itself with the free version (a couple of small nits). -- Giovanni Bajo -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrading Python Article
JanC [EMAIL PROTECTED] wrote: Fuzzyman schreef: On the other hand the microsoft compiler is *better* than gcc anyway :-) It's better at optimising, but it doesn't support standard C C++. ;-) I don't think that's fair. Visual C++ 7.1 is signficantly better at compliance than their past compilers. -- - Tim Roberts, [EMAIL PROTECTED] Providenza Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrade woes: Numeric, gnuplot, and Python 2.4
Jive wrote: Here's my sitch: I use gnuplot.py at work, platform Win32. I want to upgrade to Python 2.4. Gnuplot.py uses extension module Numeric. Numeric is now unsupported. The documentation says If you are new to Numerical Python, please use Numarray.. It's not that easy, dangit. The download page for numpy does not contain a 2.4 version of Numeric, and I suspect they do not intend to release one, because there IS a 2.4 version of Numarray. So here are my choices: 1) Switch from gnuplot.py to some other plotting package. 2) Convince, bribe, or cajole someone to implement gnuplot.py using Numarray. 3) Hack on gnuplot.py myself. (Learning curve alert!) 4) Buy a copy of the VC++ 7.1 and port Numeric myself. (I still don't know what to buy from Mr. Gates -- VC++ .net Standard?) 5) Do something else I haven't thought of. Any suggestions would be welcome. Jive I speet on backwards incompatibility Dadson Why do you want to upgrade to 2.4? What do you mean by upgrade to 2.4? Choice (5a) Install Python 2.4 and use that for whatever while continuing to use 2.3 for gnuplot. Choice (5b) Ask politely of the Numeric camp when/if they will make a 2.4-compatible Windows release. Choice (5c) Ask politely of the Python community if anyone else is contemplating making a 2.4 Windows distribution of Numeric. Choice (5d) Read replies to your fulminations in another thread -- in particular the one that says you need no truck with Mr Gates; in fact you can use free non-MS compilers to make Python extensions for Windows. -- http://mail.python.org/mailman/listinfo/python-list
Re: uptime for Win XP?
IIRC, i think it's part of the powertools or IT Toolkit Peter Hansen said: Tom Wesley wrote: Esmail Bonakdarian wrote: Is there a way to display how long a Win XP system has been up? Somewhat analogous to the *nix uptime command. I believe that uptime works from the console, but don't have a machine to check it with... Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp. c:\uptime 'uptime' is not recognized as an internal or external command, operable program or batch file. Not here, at any rate. Maybe it's part of the Productivity Kit thingy? -Peter -- http://mail.python.org/mailman/listinfo/python-list -- -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs: wxPython vs. Tkinter (and others)
Fredrik Lundh [EMAIL PROTECTED] writes: Mike Meyer wrote: It also has a widget for creating Windows wizards for walking through a set of options. Besides the fact that wizards isn't really that great (read Cooper), if your toolkit doesn't let you create a dialogue with a couple of buttons and a swappable frame, it's not a very good toolkit. (that's very easy, in both Tkinter and wxPython. You can probably find ready-made modules on the net if you look around a little) While I'm not a big fan of wizards, for some applications they are just the ticket, as you're walking down a tree of options. Presenting the user the options at each node is exactly the way to go. Sure, it may be easy to roll your own in TkInter, but in PyQt you don't have to. At the python level, slots are just callable objects. At the C++ level, slots are magic methods of objects. Signals are usually associated with GUI events, but Python can emit them for whatever reason it wants. It's possible to connect C++ signals to C++ slots/signals in Python, meaning that Python won't be involved when that signal is emitted. That's would of course be a great argument if you didn't have Python. (even if Python's slower than C++, it's a lot faster than a user). It's still nice to be able to let the C++ code handle it all. After all, having the compiled layer do things for you is what makes for fast python code. PyQt provides a higher level of abstraction. Whan what? C++ plus a low level UI API, sure. But Tkinter+Python? wxPython+Python? You gotta be kidding. No, I'm not kidding. I'm stating my general impression after having done programming with both TkInter and PyQt. Note, that's *Py*Qt, not Qt. I've never tried doing animation in TkInter. Qt provides timer devices that you can use to drive animations. I suspect that doing the same in TkInter would be noticably more difficult. Eh? You don't know how to do a loop in Python? Or register a callback? wxPython contains both timers and a low-level graphics API; for Tkinter, you the after facility and the Canvas; if you need lower-level drawing with tighter Python intergration, use the WCK. Sure, you can roll a loop together with a sleep and do animation. You can throw in threading and queues so you can keep the GUI active while you're doing it. With Qt, you tie the timer's signal to the object-moving function, and you're done. Since you have to use the threaded version to get the same functionality, I'd say noticably more difficult isn't an overstatement. 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: Upgrade woes: Numeric, gnuplot, and Python 2.4
John Machin [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Why do you want to upgrade to 2.4? What do you mean by upgrade to 2.4? Well, for one thing, when I previously installed and then uninstalled 2.4, pythonwin broke, and neither I nor the win32 gurus can figure out what the heck happened. -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrade woes: Numeric, gnuplot, and Python 2.4
Jive wrote: Here's my sitch: I use gnuplot.py at work, platform Win32. I want to upgrade to Python 2.4. Gnuplot.py uses extension module Numeric. Numeric is now unsupported. The documentation says If you are new to Numerical Python, please use Numarray.. It's not that easy, dangit. The download page for numpy does not contain a 2.4 version of Numeric, and I suspect they do not intend to release one, because there IS a 2.4 version of Numarray. I think they will as soon as someone steps up to compile it. The active maintainer uses Linux primarily, so it's not easy for him to do it himself. He's in a similar boat as you (except that he himself doesn't need a Windows binary. Natch.). -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
remove child in DOM??
Hello!! how can i remove a child in DOM ? for example, i have thi xml below: root user name juliano /name /user root and i want to remove the name element: root user /user root how can i do this?? Juliano Freitas -- http://mail.python.org/mailman/listinfo/python-list
Re: uptime for Win XP?
Esmail Bonakdarian wrote: Hi, Is there a way to display how long a Win XP system has been up? Somewhat analogous to the *nix uptime command. Thanks, Esmail It's included in the output of the 'systeminfo' command. That command is fairly slow, though (since it displays a lot more than just the up time) There's also info about the 'uptime' utility here: http://support.microsoft.com/kb/q232243/ I don't know if that works for XP. Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrade woes: Numeric, gnuplot, and Python 2.4
Jive wrote: John Machin [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Why do you want to upgrade to 2.4? What do you mean by upgrade to 2.4? Well, for one thing, when I previously installed and then uninstalled 2.4, pythonwin broke, and neither I nor the win32 gurus can figure out what the heck happened. And reinstallation of 2.3 and the Py2.3 win32all didn't fix it? Very strange. . . Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Error in msvc in building inheritance.obj to build hello.pyd
Error in msvc in building inheritance.obj to build hello.pyd
Hello,
I am trying to build the boost 1.31.0 sample extension hello.cpp.
I can not compile the file inheritance.cpp because the two
files containing some templates: adjacency_list.hpp and mem_fn.hpp can
not compile.
Does anyone have any solutions?
Instead of Visual C++ 6.0 should I use a different compiler?
Anyone have any success on any other compiler?
Did anyone manage to build a hello.pyd?
Thank you very much.
Here is my script below (with embedded results).
rem I have MSVC 6.0 Service Pack 5 on Windows 2000 Service Pack 3
default installs on F:
rem Python is located in F:\Python23
rem Boost is located in W:\boost_1_31_0
rem MSVC stlPort 4.6.2 installed, compiled and
rem VC studio include dirs and libraries dirs configured to use it.
rem build boost.jam (so I have a bjam.exe for all below)
W:
vcvars32.bat
cd W:\boost_1_31_0\tools\build\jam_src
rem below since I have multilple toolsets installed I will always be
specific.
.\build.bat msvc
rem result: 2 minutes later: NO WARN NO ERRORS
dir W:\boost_1_31_0\tools\build\jam_src\bin.ntx86\*
rem result: OK I have *jam*.exe executables: bjam.exe jam.exe
mkjambase.exe yyacc.exe
rem build boost (using boost.jam (bjam from above))
W:
vcvars32.bat
set PYTHON_ROOT=F:\Python23
set PYTHON_VERSION=2.3
set PATH=%PATH%;W:\boost_1_31_0\tools\build\jam_src\bin.ntx86
rem APPEND THE BJAM PATH ABOVE TO THE SYSTEM ENVRONMENT VARIABLE PATH
cd W:\boost_1_31_0
rem below since I have multilple toolsets installed I will always be
specific.
bjam -sTOOLS=msvc install
rem about 90 minutes later ERROR RESULTS FOLLOW:
errors.txt contents below
cl /Zm800 -nologo -GX -c -DNDEBUG -DNDEBUG -DBOOST_PYTHON_DYNAMIC_LIB
-DBOOST_PYTHON_SOURCE /Ogity /O2 /Gs /Ob2 /GX /GR /MD
-Ibin\boost\libs\python\build -IW:\boost_1_31_0
-IF:\Python23\include -IF:\Program Files\Microsoft Visual
Studio\VC98\Include
-Fobin\boost\libs\python\build\boost_python.dll\msvc\release\inheritance.obj
-TpW:\boost_1_31_0\libs\python\build\../src/object/inheritance.cpp
rem error below results below ...
F:\Program Files\Microsoft Visual Studio\VC98\Bincl /Zm800 -nologo
-GX -c -DNDEBUG -DNDEBUG -DBOOST_PYTHON_DYNAMIC_LIB
-DBOOST_PYTHON_SOURCE /Ogity /O2 /Gs /Ob2 /GX /GR /MD
-Ibin\boost\libs\python\build -IW:\boost_1_31_0
-IF:\Python23\include
-IF:\Program Files\Microsoft Visual Studio\VC98\Include
-Fobin\boost\libs\python\build\boost_python.dll\msvc\release\inheritance.obj
-TpW:\boost_1_31_0\libs\python\build\../src/object/inheritance.cpp
inheritance.cpp
W:\boost_1_31_0\boost/graph/detail/adjacency_list.hpp(1055) : error
C2244: 'bidirectional_graph_helper_with_propertyConfig::remove_edge'
: unable to resolve function overload
W:\boost_1_31_0\boost/graph/detail/adjacency_list.hpp(1057) : error
C2954: template definitions cannot nest
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2039: 'dm' : is not a
member of '_mfi'
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2143: syntax error :
missing ';' before ''
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2501: 'dm' : missing
storage-class or type specifiers
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2059: syntax error : ';'
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2059: syntax error : ''
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2653: 'T' : is not a
class or namespace name
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2645: no qualified name
for pointer to member (found ':: *')
W:\boost_1_31_0\boost/mem_fn.hpp(320) : error C2143: syntax error :
missing ';' before '}'
W:\boost_1_31_0\boost/mem_fn.hpp(320) : fatal error C1506:
unrecoverable block scoping error
F:\Program Files\Microsoft Visual Studio\VC98\Bin
W:\boost_1_31_0\boost/graph/detail/adjacency_list.hpp(1055) : error
C2244: 'bidirectional_graph_helper_with_propertyConfig::remove_edge'
: unable to resolve function overload
W:\boost_1_31_0\boost/graph/detail/adjacency_list.hpp(1057) : error
C2954: template definitions cannot nest
rem the problem area in adjacency_list.hpp is here ...
template class Config
inline void
bidirectional_graph_helper_with_propertyConfig::remove_edge(typename
Config::edge_descriptor e)
{
typedef typename Config::graph_type graph_type;
graph_type g = static_castgraph_type(*this);
boost::remove_edge(source(e, g), target(e, g), *this);
}
// O(E/V) or O(log(E/V))
template class EdgeOrIter, class Config
inline void
remove_edge(EdgeOrIter e,
bidirectional_graph_helper_with_propertyConfig g_)
{
g_.remove_edge(e);
}
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2039: 'dm' : is not a
member of '_mfi'
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2143: syntax error :
missing ';' before ''
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2501: 'dm' : missing
storage-class or type specifiers
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2059: syntax error : ';'
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2059: syntax error : ''
W:\boost_1_31_0\boost/mem_fn.hpp(315) : error C2653: 'T' : is not a
Re: PEP 338: Executing modules inside packages with '-m'
A useful feature that is a logical extension of current '-m' behaviour. (I'm actually surprised it was left out in the first place) This will definitely allow me and other python programmers to package our scripts better Sounds Good to me. (-; Thank you for the PEP AK -- http://mail.python.org/mailman/listinfo/python-list
Re: Error in msvc in building inheritance.obj to build hello.pyd
Donne Leen, Thanks, thats a very good solution. I am glad to hear that the later solution works for you. I will try to get the 1.32.0 source Monday. I will try to compile again next week. Andre Mikulec AIM -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 338: Executing modules inside packages with '-m'
[EMAIL PROTECTED] wrote: A useful feature that is a logical extension of current '-m' behaviour. (I'm actually surprised it was left out in the first place) That seems to be a common reaction :) It was dropped for 2.4 because I wasn't sure exactly how it should work, and 2.4 was already in beta at the time. So I went with the cookbook recipe instead. Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Howto Extract PNG from binary file @ 0x80?
Hi, As a newbie to the language, I have no idea where to start..please bare with me.. The simcity 4 savegame file has a png image stored at the hex location 0x80. What I want to extract it and create a file with the .png extension in that directory. Can somebody explain with a snippet of code how I would accomplish this? I've looked around but the information is too vague and I don't know how to start. -thanks in advance -- http://mail.python.org/mailman/listinfo/python-list
Re: High level SNMP
Jeremy Sanders wrote: Hi - I'd like to write a program which basically does a few snmpgets. I haven't been able to find a python package which gives you a nice high-level and simple way of doing this (like PHP has). Everything appears to be extremely low level. All I need is SNMPv1. Does anyone know of a simple python package for doing this? I'd rather have something written in pure python, so that it is easily cross-platform. Jeremy The pyNMS package at sourceforge has a complete SNMP (v1, v2c) implementation. In pure Python, and fairly self contained. See http://sourceforge.net/projects/pynms There are few docs, sorry. If you want to use it and have any questions then please let me know (I wrote it). BTW, you can also read MIB files if you have libsmi installed. But the pyNMS package contains a utility called mib2py that converts MIB objects to Python, and the pyNMS package has most standard MIBS pre-compiled. So, you don't really need libsmi to use the standard MIBs. The name means Python Network Management System, and will become a complete network management system with GUI and scriptability soon. ;-) There is some support for creating XHTML reports, NMS web interface, SNMP get/set, SNMP trap receiver, Ping/ICMP module, process management, MIB browser, CLI construction kit, web protocols, easy email interface, and asyncio framework. Works well with Linux or FreeBSD. (PS. It can also answer your phone and take a message) -- \/ \/ (O O) -- oOOo~(_)~oOOo Keith Dart [EMAIL PROTECTED] vcard: http://www.kdart.com/~kdart/kdart.vcf public key: ID: F3D288E4 URL: http://www.kdart.com/~kdart/public.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Raw Sockets vs. What?
So, the question: How to communicate between two instances of the python interpreter? Specifically, I need to pass the api and objects from bdb, the base class for the debugger. One interpreter runs the ide, the other the debugger and client code. We were talking and just opening a socket and doing the rest from there came up. This, to me, (admitedly a java guy) seems like a lot of work. If it were just setting breakppoints and stepping, well ok. But I also want to have introspection on the debugger side objects. I could use raw sockets and write a bunch of stuff. Does anyone have a suggestion about some pythonesque way to tackle this? I've found pyro useful for a similar task: I fork, create a pipe and in the child I create a pyro daemon to run a remote object. The uri of that then is passed using the pipe, so that the parent can get a reference to the remote object. I do the whole exercise due to not killable threads in python - so that I can terminate the subprocess. The nice thing about pyro is that it is like corba without the declartive stuff - just use it. You also migh check out the eric ide - it has an out-of-process debugger, so Detlev must have found a solution :) -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
How to remove packages - wxPython
Linux kernel 2.6.9 Slackware 10 Python version 2.3.4 wxPython version 2.4.2.4 I compiled and installed wxPython. There is no uninstall script that I can find for the py components. The library component has a make uninstall. What is the proper way to uninstall packages? I searched everywhere, but there seems to be no clearcut explanation. Can I just remove the site-package directories it created? Or is there a central config file for python? Thx. -- http://mail.python.org/mailman/listinfo/python-list
your favorite quick reference? (was Python Docs. Hardcopy 2.4 Library Reference, interested?)
somewhat related .. is there a good quick reference for python? o'reilly has a quick ref guide 2nd ed is a few years old, and the ones i have found on-line seem a bit big. I am looking for something relatively concise that I can carry with me ... not sure such a thing exists? thanks. -- http://mail.python.org/mailman/listinfo/python-list
SocketServer class examples
Hello Fred,
I just ran across your question. I think that the following
code will work:
- SERVER CODE --
import SocketServer
import time
class GreetingHandler(SocketServer.BaseRequestHandler):
'''Class to handle sending a greeting to a client
'''
def handle(self):
'''Method to actually handle the greeting
'''
print 'handling the request'
line = self.request.recv(bufsize)
name =
if ('NAME:' in line):
name = line.split('NAME:')[1]
self.request.sendall('hello there %s \n' % name)
def manageServer():
'''Function to manage the running of the server and handling of
requests
'''
servObj = SocketServer.TCPServer(('localhost',6099),GreetingHandler)
print 'Starting the server...'
servObj.serve_forever()
if __name__ == '__main__':
manageServer()
- CLIENT CODE -
#!/usr/bin/env python
import socket
def manageClient():
'''Function to manage the sending of request to the server
'''
server = 'localhost'
port = 6099
servObj = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
servObj.connect((server, port))
servObj.send('NAME: An Elephant\r\n')
resp = servObj.recv(8192)
print resp
servObj.close()
if __name__ == '__main__':
manageClient()
I think that the problem with the rfile and wfile methods in the
StreamRequestHandler class is that it's trying to send on the
same socket as it's reading data on so they are blocking each
other. I think that this is a problem in the StreamRequestHandler
class.
adil
-Original Message-
From: Frederick Grim [mailto:fgrim at norby.dyndns.org]
Sent: 18 July 2004 19:34
To: python-list at python.org
Subject: SocketServer class examples
Howdy group,
So I am in the middle of using the socketserver class from the std
library and have run into a problem that probably reveals my
misunderstanding of sockets. I have a class defined like so:
class tcp_listener(SocketServer.ThreadingTCPServer):
def __init__(self, addr, port):
SocketServer.ThreadingTCPServer.__init__(self, \
(addr, port), Daemon.request_handler)
Yes I realize the above is silly and redundant
And a request handler in Daemon that has a handle function that works like
so:
def __req_handle(self, req):
Do stuff with req and return a response afterwards
return response
def handle(self);
while True:
input = self.rfile.readline()
request = input
while input and not re.search('EOF$', input):
input = self.rfile.readline()
request += input
self.wfile.write(self.__req_handle(request))
The client end looks almost identical to the example in the python docs.
So
the problem here is that this code doesn't work. Using tcpdump I can tell
that the client is sending to the server properly but the server is never
responding. Or when it tries to respond it gets stuck in the write.
What's
going on here. I can't seem to find a single example of how to use this
class on the client and server side and I don't want to use twisted
(because
I should understand how this works instead of relying on canned software).
Does anyone know where I can find an example of a functioning SocketServer
and client? Google seems to help nought here.
Thanks,
Fred
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python vs. Perl
Roy Smith already touched on regular expressions, but as far as features go, I would say that the real difference between python and perl is not in the features, but in the philosophy. It seems to me that any program you can write in python could also be written in perl. What it comes down to for me was which language most fit the way I tend to think. I decided python was that language, and I found everything very intuitive. I have a good friend who thinks in perl and is very productive using it. Other people might disagree, but when I was looking at perl and python I borrowed recent copies of Learning Perl and Learning Python from the O'Reilly series and after reading each, decided I preferred python. You can find out about most of the features in those books. Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: swig Python question
Whether SWIG will work in a no brainer way or not depends on the original code, I think. If the original code uses a very convoluted design, of course things will get hairy. If the package uses a very clean structure, I think you will find SWIG works out very nicely. The intriguing things is, however, once you structure the package to a form SWIG would work, it opens up the door to support multiple script languages (and they have a long list of supported script languages). If you hand crafted it to run the Python-C API, then you can only use Python as script. -- It's me Keith Dart [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] It's me wrote: It's me [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I am playing around with SWING building a Python module using the no brainer example in http://www.swig.org/tutorial.html. With that first example, Oops! Soapy fingers. SWIG - not SWING. -- It's me. I have used SWIG before, and it's not always such a no-brainer. In fact, it rarely is except for trivial examples. But it can work. I think it is best suited for wrapping large libraries. For small stuff, it would be better to just do it manually using the Python C API. Good luck. -- It's not me. -- \/ \/ (O O) -- oOOo~(_)~oOOo-- -- Keith Dart [EMAIL PROTECTED] public key: ID: F3D288E4 -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie questions
Hello again everyone ,
var2[:]=[] has solved my problem, and I don't understand why it is
programming by side effect.
I don't think it's bad, look at this, it's what I've done :
def Clear(lvar)
lvar[:]=[]
def main (starting class)
var1=[]
var1.append('a')
Clear(var1)
var1 can only be modified by Clean(), so, if I need to debug var1, I
quickly know that I must look in Clean()
For me programming by side effect is that :
def Clear(lvar)
var1=[]
def main (starting class)
global var1=[]
var2=[]
var1.append('a')
Something(var2)
I am wrong?
Dominique.
--
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Re: How to remove packages - wxPython
Peter Hansen wrote: Peter wrote: Linux kernel 2.6.9 Slackware 10 Python version 2.3.4 wxPython version 2.4.2.4 I compiled and installed wxPython. There is no uninstall script that I can find for the py components. The library component has a make uninstall. What is the proper way to uninstall packages? I searched everywhere, but there seems to be no clearcut explanation. Can I just remove the site-package directories it created? Or is there a central config file for python? Generally speaking, just removing the subfolder(s) from site-packages will completely remove an extension. Some few extensions will also create a .pth file in the site-packages folder, so check for that as well. No doubt there are exceptions, but I believe this will cover 95% of the cases. -Peter That's what I thought. Just wanted to be sure. I think this program actually created two separate site-packages folder, wxPython and wx. I need to check the install script and see what was doing. Thx -- http://mail.python.org/mailman/listinfo/python-list
handy stacktrace class
I was fooling with some Python code, and starting to miss the Exception.printStackTrace() feature in Java. Here is a stab at something roughly analogous, which puts together a stacktrace as an XML document. import xml.dom.minidom class Stacktrace(xml.dom.minidom.Document): def __init__(self): import sys xml.dom.minidom.Document.__init__(self) stacktrace = self.createElement(stacktrace) self.appendChild(stacktrace) try: raise Exception except: tb = sys.exc_traceback x = tb.tb_frame.f_back while x != None: f = x.f_code frame = self.createElement(frame) frame.setAttribute(func, f.co_name) frame.setAttribute(file, f.co_filename) frame.setAttribute(line, repr(f.co_firstlineno)) stacktrace.appendChild(frame) x = x.f_back def __repr__(self): import xml.dom.ext class MyStream: def __init__(self): self.str = def write(self, x): self.str += x stream = MyStream() xml.dom.ext.PrettyPrint(self, stream) return stream.str[:-1] # trim trailing newline The rational for doing this as an XML document was, uh, gee, I thought I had a good reason at the time. I think I've seen XML sequences of stacktraces elsewhere and it looked like a good idea. My brief time of muddling about with xml.dom.minidom makes me think that elements are inherently tied to a particular document and can't just be lifted and moved to another document, as one might want to do to, say, build a sequence of stacktraces while debugging something. But I'm sure there's some kind of workaround for that. -- http://mail.python.org/mailman/listinfo/python-list
Overriding properties
Why does the following print 0 0 instead of 0 1? What is the canonical way to rewrite it in order to get what I obviously expect? class C(object): __val = 0 def set_value(self, val): if val 0 : self.__val = 0 else : self.__val = val def get_value(self): return self.__val value = property(get_value, set_value) class CC(C): def set_value(self, val): if val 0: self.__val = 1 else : self.__val = val c = C() cc = CC() c.value = -1 cc.value = -1 print c.value, cc.value Thanks in advance /npat -- http://mail.python.org/mailman/listinfo/python-list
Re: from vb6 to Python
Luis M. Gonzalez wrote: MarcoL wrote: Hello, I am a VB6 programmer and I would like to learn a new high level language (instead of restarting from scratch with .NET... I'd like to add that by going with Python, you'll also be able to develop for .NET. Check this out: www.ironpython.com . Since the development of Ironpython is now being funded by Microsoft, you'll get the best of both worlds: An already excellent cross-platform, object oriented language and a fully compliant .NET language for Windows and Linux (through Mono and DotGnu). Unfortunately this is currently not near production use, and whether Microsoft is funding IronPython development is up in the air: One IronPython fan noted a disconcerting silence in IronPython development: http://usefulinc.com/edd/blog/contents/2004/12/09-jvm/read Of course it'll all resolve itself one way or another eventually, just wanted to correct the impression that IronPython is ready to go already. Regards, Martijn -- http://mail.python.org/mailman/listinfo/python-list
PEP 338: Executing modules inside packages with '-m'
Python 2.4's -m command line switch only works for modules directly on sys.path. Trying to use it with modules inside packages will fail with a Module not found error. This PEP aims to fix that for Python 2.5. Previously, posting of a draft version of the PEP to python-dev and python-list didn't actually generate any responses. I'm not sure if that's an indication that people don't see the restriction to top-level modules as a problem (and hence think the PEP is unecessary), or think the extension to handle packages is obvious (and hence see no need to comment). Or, it could just be a sign that Python 2.4 hasn't been out long enough for anyone to care what I'm yabbering on about :) Anyway, all comments are appreciated (even a simple Sounds good to me). Cheers, Nick. *** PEP: 338 Title: Executing modules inside packages with '-m' Version: $Revision: 1.2 $ Last-Modified: $Date: 2004/12/11 20:31:10 $ Author: Nick Coghlan [EMAIL PROTECTED] Status: Draft Type: Standards Track Content-Type: text/x-rst Created: 16-Oct-2004 Python-Version: 2.5 Post-History: 8-Nov-2004 Abstract This PEP defines semantics for executing modules inside packages as scripts with the ``-m`` command line switch. The proposed semantics are that the containing package be imported prior to execution of the script. Rationale = Python 2.4 adds the command line switch ``-m`` to allow modules to be located using the Python module namespace for execution as scripts. The motivating examples were standard library modules such as ``pdb`` and ``profile``. A number of users and developers have requested extension of the feature to also support running modules located inside packages. One example provided is pychecker's ``pychecker.checker`` module. This capability was left out of the Python 2.4 implementation because the appropriate semantics were not entirely clear. The opinion on python-dev was that it was better to postpone the extension to Python 2.5, and go through the PEP process to help make sure we got it right. Scope of this proposal == In Python 2.4, a module located using ``-m`` is executed just as if its filename had been provided on the command line. The goal of this PEP is to get as close as possible to making that statement also hold true for modules inside packages. Prior discussions suggest it should be noted that this PEP is **not** about any of the following: - changing the idiom for making Python modules also useful as scripts (see PEP 299 [1]_). - lifting the restriction of ``-m`` to modules of type PY_SOURCE or PY_COMPILED (i.e. ``.py``, ``.pyc``, ``.pyo``, ``.pyw``). - addressing the problem of ``-m`` not understanding zip imports or Python's sys.metapath. The issues listed above are considered orthogonal to the specific feature addressed by this PEP. Current Behaviour = Before describing the new semantics, it's worth covering the existing semantics for Python 2.4 (as they are currently defined only by the source code). When ``-m`` is used on the command line, it immediately terminates the option list (like ``-c``). The argument is interpreted as the name of a top-level Python module (i.e. one which can be found on ``sys.path``). If the module is found, and is of type ``PY_SOURCE`` or ``PY_COMPILED``, then the command line is effectively reinterpreted from ``python options -m module args`` to ``python options filename args``. This includes setting ``sys.argv[0]`` correctly (some scripts rely on this - Python's own ``regrtest.py`` is one example). If the module is not found, or is not of the correct type, an error is printed. Proposed Semantics == The semantics proposed are fairly simple: if ``-m`` is used to execute a module inside a package as a script, then the containing package is imported before executing the module in accordance with the semantics for a top-level module. This is necessary due to the way Python's import machinery locates modules inside packages. A package may modify its own __path__ variable during initialisation. In addition, paths may affected by ``*.pth`` files. Accordingly, the only way for Python to reliably locate the module is by importing the containing package and inspecting its __path__ variable. Note that the package is *not* imported into the ``__main__`` module's namespace. The effects of these semantics that will be visible to the executed module are: - the containing package will be in sys.modules - any external effects of the package initialisation (e.g. installed import hooks, loggers, atexit handlers, etc.) Reference Implementation A reference implementation is available on SourceForge [2]_. In this implementation, if the ``-m`` switch fails to locate the requested module at the top level, it effectively reinterprets the command from ``python -m script`` to ``python -m execmodule script``. (There
problem with embbed boost.python in multi-interpreter and multi-thread HELP please
I wrote a program embbed boost.python, each thread running a sub-interpreter, i made a module implement by boost.python, and i wish this module imported in each sub-interpreter, i find that the module could initialize only once, otherwise the boost.python will throw a exception said that something already registered; second conversion method ignored. So I try another way, initialize and import the module in one interpreter such as the main interpreter, and I hope to import the module in any sub-interpreter, because I found the python document said: Extension modules are shared between (sub-)interpreters as follows: the first time a particular extension is imported, it is initialized normally, and a (shallow) copy of its module's dictionary is squirreled away. When the same extension is imported by another (sub-)interpreter, a new module is initialized and filled with the contents of this copy; the extension's init function is not called. but when i try this way i found that the program throw an exception:ImportError: No module named mym, (mym is the module name). This happens even i wrote the module in Python/C API without boost.python. Could somebody tell me why this happened or how to deal with it, thanks for any suggestion. Donnie Leen -- http://mail.python.org/mailman/listinfo/python-list
