Re: Accessing class variable at class creation time
It might be that I'm complicating something easy here, but I immediately thought of import sys class A: X = 2 def F(): f = sys._getframe().f_back print f.f_locals["X"] F() -- http://mail.python.org/mailman/listinfo/python-list
Re: bug or feature?
Python.org General FAQ 1.4.21: Why are default values shared between objects? (http://www.python.org/doc/faq/general.html#why-are-default-values-shared-between-objects) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python interpreter bug
Why would it be a bug? You've made it so that every instance of OBJ is equal to every other instance of OBJ. The behaviour is as expected. -- http://mail.python.org/mailman/listinfo/python-list
Re: subtle side effect of generator/generator expression
If you find that you want to iterate over an iterable multiple times, have a look at the solution that the tee() function in the itertools module provides (http://docs.python.org/lib/itertools-functions.html). (Have a look at the rest of the itertools module as well, for that matter.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple server/client application
You're calling the grid() method on the Entry object you're instanciating. Are you sure that the grid() method returns the Entry object so that you're actually binding it to self.myAddress? -- http://mail.python.org/mailman/listinfo/python-list
Re: ElementTree - Why not part of the core?
Before that can happen we'll need some better management of co-existing different versions of a package. You'll want to be able to use newer versions of external packages without breakage in the standard library. -- http://mail.python.org/mailman/listinfo/python-list
Re: What are __slots__ used for?
Most have already been said, but have a look at http://docs.python.org/ref/slots.html for authoritative documentation. -- http://mail.python.org/mailman/listinfo/python-list
Re: python classes taught
Yeha, sure. The Royal Institute of Technology in Stockholm, Sweden teaches Python for some of its introductory programming and algorithm courses. -- http://mail.python.org/mailman/listinfo/python-list
Re: Release of PyPy 0.7.0
That's great! Congratulations! -- http://mail.python.org/mailman/listinfo/python-list
Re: sizeof(long) from python
Take a look at the struct module (http://docs.python.org/lib/module-struct.html), it does what you want. -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in "metaclass resolution order" ?
Have you read the "Metaclasses" part of "Unifying types and classes in Python 2.2"? (http://www.python.org/2.2.3/descrintro.html#metaclasses) It discusses and explains the issues you seem to have. -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in "metaclass resolution order" ?
If you have read the document I referred you to, did you also read the example where classes M1, M2, M3 and M4 were defined? A quote from the discussion of that example: "For class D, the explicit metaclass M1 is not a subclass of the base metaclasses (M2, M3), but choosing M3 satisfies the constraint, so D.__class__ is M3." Isn't that exactly what you are doing? -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in "metaclass resolution order" ?
I definitely think that it's the intended behaviour: the example shows how and why it works; and I definitely agree that it should be documented better. -- http://mail.python.org/mailman/listinfo/python-list
Re: threads/sockets quick question.
Why do you check if the module threading is less than 50? (this is why nothing happens, it's always false). >From where do you get port_counter in method run() of scanThread? (this would make every call to run() raise an exception. -- http://mail.python.org/mailman/listinfo/python-list
Re: programmatically calling a function
You might also want to take a peek at the getattr() function: http://docs.python.org/lib/built-in-funcs.html#l2h-31 -- http://mail.python.org/mailman/listinfo/python-list
Re: function expression with 2 arguments
Actually, lambda forms are quite precisely documented at http://docs.python.org/ref/lambdas.html if you feel than reading the tutorial (specifically http://docs.python.org/tut/node6.html section 4.7.5) is too base for you. -- http://mail.python.org/mailman/listinfo/python-list
Re: issues installing readine-1.12 on WinXP
That shouldn't happen AFAICT. Check line 108 in keysyms.py and make sure it says "vk = VkKeyScan(ord(char))". -- http://mail.python.org/mailman/listinfo/python-list
Re: issues installing readine-1.12 on WinXP
Possibly. Is the ` sign available as an unmodified key? -- http://mail.python.org/mailman/listinfo/python-list
Re: issues installing readine-1.12 on WinXP
Well, just modify the source in that case. -- http://mail.python.org/mailman/listinfo/python-list
Re: __getitem__ method on (meta)classes
Well, they're not synonymous. At least not in that context. If you haven't already tried it, what you're doing will fail for instances as well. Look in typeobject.c to see why. The gist of it is that the special methods are looked up on the type rather than the instance (on the metaclass rather than on the class, in your case), so the internal lookup mechanism ignore instance attributes completely in this case. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python info
Well, the source code is pretty well documented if you want to get to know the implementation. Read the "Extending and Embedding" tutorial and the "Python/C API" reference, then start digging through the code. Performance comparisons are broadly available, and always suspect. -- http://mail.python.org/mailman/listinfo/python-list
Re: decorating classes with metaclass
Class decoration was discussed back when (you can search for the thread in python-dev); not as an alias to metaclasses but discussed as having exactly the same semantics as function decoration. Maybe the idea has more merit as being another way of setting the __metaclass__ attribute; on the other hand: it doesn't increase visibility and what is does and how it does it is very different from that of function decoration; so perhaps not. -- http://mail.python.org/mailman/listinfo/python-list
Re: readonly class attribute ?
Start the attribute name with "_" and don't document it. If clients mess with it, they're to blame. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to create stuffit files on Linux?
Stuffit Expander can handle zip, rar, tar, gz, etc, etc, etc. Don't worry. -- http://mail.python.org/mailman/listinfo/python-list
Re: os.path query functions behavior incorrect?
> These to me are I/O errors that should result in an exception. > Doing a command line dir a:\ reports "The system cannot find > the path specified." The functions use the underlying C library, and in this case, the result is not guaranteed by the standard. -- http://mail.python.org/mailman/listinfo/python-list
Re: def a((b,c,d),e):
You can always unpack a tuple that way, like in: .>>> import sys .>>> for (index, (key, value)) in enumerate(sys.modules.iteritems()): pass -- http://mail.python.org/mailman/listinfo/python-list
Re: Inheritance problem?
Don't use self.__class__, use the name of the class. -- http://mail.python.org/mailman/listinfo/python-list
Re: Help in using introspection to simplify repetitive code
[EMAIL PROTECTED] wrote: > Hello. > I'm writing a proxy class, i.e: a class whose methods mostly delegate > their functionality to other class object. Most of the methods (which > are quite a lot) defined in the class would end up being: > > def thisIsTheMethodName(self): > self._handlerClass.thisIsTheMethodName() > > The handler object is the same in all methods. > > I was wondering if there is a way to simplify this proxy class, maybe > using some pythonic technique like metaclasses, introspection... any > suggestion is appreciated. > > Thanks, > > Javier Sanz http://docs.python.org/ref/attribute-access.html#l2h-206 -- http://mail.python.org/mailman/listinfo/python-list
Re: Python less error-prone than Java
Actually, you're wrong on all levels.
First: It's perfectly simple in Java to create a binary sort that sorts
all arrays that contain objects; so wrong there.
Secondly: The bug has nothing to do with static typing (I'm guessing
that's what you meant. Both Python and Java are strongly typed). The
problem is that ints are bounded in Java. They could easily have been
ints and then automatically coerced to (equivalent to) longs when they
got bigger; that they aren't is more a design fault than anything to do
with static typing. The equivalent in Python would have been if an
overflow exception was raised when the int got too big. It might have
been that way, typing or no typing.
Christoph Zwerschke wrote:
> You will often hear that for reasons of fault minimization, you should
> use a programming language with strict typing:
> http://turing.une.edu.au/~comp284/Lectures/Lecture_18/lecture/node1.html
>
> I just came across a funny example in which the opposite is the case.
>
> The following is a binary search algorithm in Java. It searches a value
> in an ordered array a of ints:
>
> public static int binarySearch(int[] a, int key) {
> int low = 0;
> int high = a.length - 1;
> while (low <= high) {
> int mid = (low + high) / 2;
> int midVal = a[mid];
> if (midVal < key)
> low = mid + 1;
> else if (midVal > key)
> high = mid - 1;
> else
> return mid; // key found
> }
> return -(low + 1); // key not found.
> }
>
> Now the same thing, directly converted to Python:
>
> def binarySearch(a, key):
> low = 0
> high = len(a) - 1
> while low <= high:
> mid = (low + high) / 2
> midVal = a[mid]
> if midVal < key:
> low = mid + 1
> elif midVal > key:
> high = mid - 1;
> else:
> return mid # key found
> return -(low + 1) # key not found.
>
> What's better about the Python version? First, it will operate on *any*
> sorted array, no matter which type the values have.
>
> But second, there is a hidden error in the Java version that the Python
> version does not have.
>
> See the following web page if you dont find it ;-)
> http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html
>
> -- Christoph
--
http://mail.python.org/mailman/listinfo/python-list
Re: numeric/numpy/numarray
Bryan wrote: > hi, > > what is the difference among numeric, numpy and numarray? i'm going to start > using matplotlib soon and i'm not sure which one i should use. > > > this page says, "Numarray is a re-implementation of an older Python array > module > called Numeric" > http://www.stsci.edu/resources/software_hardware/numarray > > this page says, "NumPy derives from the old Numeric code base and can be used > as > a replacement for Numeric." > http://numeric.scipy.org/ > > i looked at the matplotlib examples today and if i remember correctly, the > examples didn't use numarray. > > so i'm a bit confused. > > thanks, > > bryan Look again at numeric.scipy.org, and this time: read the whole page, especially the section called "Older Array Packages". -- http://mail.python.org/mailman/listinfo/python-list
Re: FIXED: Re: optparse multiple arguments
Ritesh Raj Sarraf wrote:
> Ritesh Raj Sarraf wrote:
> > I just noticed that the args variable is holding values b and c.
> > the args variables comes from:
> > (options, args) = parser.parse_args()
> >
> > I guess I only need to figure out now is why args isn't storing
> > argument "a" also...
> >
> > Ritesh
>
> I fixed it, I guess.
>
> parser.add_option("", "--my-option", dest="my_option",
> action="store_true")
>
> sets my_option to True and the arguments are all stored in the list
> "args". :-)
>
> Ritesh
It might do you good to read the documentation instead of blindly
experimenting.
Anyway,
parser.add_option("", "--my-option", nargs=3)
http://docs.python.org/lib/optparse-standard-option-actions.html
--
http://mail.python.org/mailman/listinfo/python-list
Re: where the extra space comes from on the stdout
alf wrote:
> Hi,
>
> I can not find out where the extra space comes from. Run following:
>
> import os,sys
> while 1:
> print 'Question [Y/[N]]?',
> if sys.stdin.readline().strip() in ('Y','y'):
> #do something
> pass
>
> $ python q.py
> Question [Y/[N]]?y
> Question [Y/[N]]?y
> Question [Y/[N]]?y
> Question [Y/[N]]?y
> Question [Y/[N]]?n
> Question [Y/[N]]?
> Question [Y/[N]]?
>
>
> There is a space evrywhere just before Q
>
> Any insight?
You already got the answer, but as for the rest: It's really easier for
you if you use raw_input() for your question/input pair instead.
--
http://mail.python.org/mailman/listinfo/python-list
Re: TypeError when subclassing 'list'
The error you're seeing is because you've rebound 'list' to something else. Try putting "list = type([])" somewhere above your code. -- http://mail.python.org/mailman/listinfo/python-list
Re: calling a class method
Read this: http://users.rcn.com/python/download/Descriptor.htm Long story short: The type of the instance is passed along together with the instance itself. -- http://mail.python.org/mailman/listinfo/python-list
Re: handling more databases with ZEO
You should take a look at http://www.zope.org/Wikis/ZODB/FrontPage/guide/index.html -- http://mail.python.org/mailman/listinfo/python-list
Re: MacOS X drag & drop?
Take a look at Platypus at http://sveinbjorn.sytes.net/platypus. It will make it easier for you. -- http://mail.python.org/mailman/listinfo/python-list
Re: readline module and white-space
Take a look at readline.get_completer_delims() and readline.set_completer_delims(). -- http://mail.python.org/mailman/listinfo/python-list
Re: line-by-line output from a subprocess
Okay, so the reason what you're trying to do doesn't work is that the
readahead buffer used by the file iterator is 8192 bytes, which clearly
might be too much. It also might be because the output from the
application you're running is buffered, so you might have to do
something about that as well.
Anyway, if the output from the child application is unbuffered, writing
a generator like this would work:
def iterread(fobj):
stdout = fobj.stdout.read(1) # or what you like
data = ""
while stdout:
data += stdout
while "\n" in data:
line, data = data.split("\n", 1)
yield line
stdout = fobj.stdout.read(1)
if data:
yield data,
--
http://mail.python.org/mailman/listinfo/python-list
Re: overhead of starting threads
How much you gain by starting threads is also determined by what you're doing in those threads. Remember (or learn): In CPython only one thread at a time can execute python code, so depending on your task threading might gain you little. If you're doing I/O or calling functions written in C (and if they release the Global Intepreter Lock [GIL]) you might gain a lot by using threads. As for overhead: profile, profile, profile. You'll have to do sample runs and find your sweet-spot. It all depends on what you're doing in the threads. -- http://mail.python.org/mailman/listinfo/python-list
Re: line-by-line output from a subprocess
Jp Calderone wrote: > Or, doing the same thing, but with less code: Hmm ... What have I been smoking? -- http://mail.python.org/mailman/listinfo/python-list
Re: vim configuration for python
I don't know if the binary editions include the Misc directory, but if you download the Python source you'll find a directory called Misc. In it, there's a vimrc file. -- http://mail.python.org/mailman/listinfo/python-list
Re: __call__
Look at http://docs.python.org/ref/callable-types.html >>> class Test(object): ... def __call__(self): ... print "the instance was called" ... >>> t = Test() >>> t() the instance was called Is this what you wanted? -- http://mail.python.org/mailman/listinfo/python-list
Re: PYTHONSTARTUP and the -i command line option
After entering the interpreter, you could do an execfile on the .pythonrc file. -- http://mail.python.org/mailman/listinfo/python-list
Re: socket programming related.
On Jul 12, 2:35 am, [EMAIL PROTECTED] wrote:
> On Jul 11, 7:32 pm, [EMAIL PROTECTED] wrote:
>
> > I have just started working in network programming using python.
> > written code for socket connection between client and server. Client
> > sent data to server for server processing (also server echoing back
> > rcvd data to client). When there is ("if no data": break ) no data
> > from client then the while loops break in server. The server program
> > process recvd data and my requirement is to send back the *results* to
> > client program for user sake. I did many trials but no use, as these
> > socket calls are blocking, i could not make my req.
>
> I just need to add a line. The while loop in server breaks when the
> sockObj.close() happens in client program indicating there is no data
> from client.
Well, you shouldn't do a close() on the client socket, you should do a
shutdown(1).
--
http://mail.python.org/mailman/listinfo/python-list
Re: pytz giving incorrect offset and timezone
On Jul 12, 11:47 am, Sanjay <[EMAIL PROTECTED]> wrote:
> Hi All,
>
> Using pytz, I am facing a problem with Asia/Calcutta, described below.
>
> Asia/Calcutta is actually IST, which is GMT + 5:30. But while using
> pytz, it was recognized as HMT (GMT + 5:53). While I digged into the
> oslan database, I see the following:
>
> # Zone NAME GMTOFF RULES FORMAT [UNTIL]
> Zone Asia/Calcutta 5:53:28 - LMT 1880 # Kolkata
>5:53:20 - HMT 1941 Oct # Howrah Mean Time?
>6:30 - BURT 1942 May 15 # Burma Time
>5:30 - IST 1942 Sep
>5:30 1:00 IST 1945 Oct 15
>5:30 - IST
>
> Searching in this group, I saw a similar problem posted
> athttp://groups.google.co.in/group/comp.lang.python/browse_thread/threa...
> without any solutions.
>
> I mailed to Stuart and also posted it at the launchpad of pytz, but
> did not get any response.
>
> Unable to know how to proceed further. Any suggestion will be of vital
> help.
>
> thanks
> Sanjay
I don't use pytz myself that often so I can't be sure, but I don't
think it's a bug in pytz.
The problem seems to be that the timezone has changed for the
location. Now, without a date as reference, pytz can't know what
timezone to use when constructing the tzinfo; you might want a date
from the 1800's.
When you're constructing the datetime with the tzinfo argument, you're
saying: use this timezone as the local timezone. datetime_new (the
constructor in C) never calls the tzinfo to verify that the timezone
is still valid, it just uses it.
On the other hand: When you construct a datetime with datetime.now()
and pass a timezone, datetime_now (again, in C) calls the method
fromutz() on the tzinfo object. Now the pytz tzinfo object has a
reference by which to choose the current timezone for the location,
and that's why it's correct when you use datetime.now() but not for a
manual construction.
A "workaround" (or maybe the proper way to do it) is to construct the
datetime without a tzinfo set, and then use the localize() method on
the tzinfo object, this will give you the correct result.
>>> tz = pytz.timezone("Asia/Calcutta")
>>> mydate = datetime.datetime(2007, 2, 18, 15, 35)
>>> print tz.localize(mydate)
2007-02-18 15:35:00+05:30
--
http://mail.python.org/mailman/listinfo/python-list
Re: gcc errors
It doesn't think you're on an intel box, it thinks you want to compile universal libraries, since you installed a universal python. The problem is likely to be that you haven't installed SDK's for intel as well as powerpc when you installed Apple's Developer Tools. Do that, and it should work ... I think. -- http://mail.python.org/mailman/listinfo/python-list
Re: elementtidy, \0 chars and parsing from a string
Well, it seems you can do: parser = elementtidy.TidyHTMLTreeBuilder.TidyHTMLTreeBuilder() parser.feed(your_str) tree = elementtree.ElementTree.ElementTree(element=parser.close()) Look at the parse() method in the ElementTree class. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pyrex speed
You can gain substantial speed-ups in very certain cases, but the main point of Pyrex is ease of wrapping, not of speeding-up. Depending on what you're doing, rewriting in Pyrex or even in C, using the Python/C API directly, might not gain you much. -- http://mail.python.org/mailman/listinfo/python-list
