Re: SV: Changing the size of a Button
On Sun, 09 Mar 2008 19:45:58 +0100, K Viltersten wrote: What i wish to do is to affect the size of the button but not due to change of text but due to resize of the frame it resides in. This far i've managed to get a callback to a function as the resize occurs and to print the sizes. However, i'd like to assign these values to the button so it always stays the same width as the frame. Don't do it yourself, pack with the `fill` argument set to `Tkinter.X`. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Classes and modules are singletons?
On Thu, 06 Mar 2008 11:06:50 -0800, castironpi wrote: On Mar 6, 8:30 am, Carl Banks [EMAIL PROTECTED] wrote: Anyway, the answer to what you are probably asking is No. Try this: import module c1 = module.Someclass reload(module) c2 = module.Someclass c1 is c2 What about o= object() b1= o.someattr reload( o ) b2= o.someattr b1 is b2 ? You are really a bit thick, a troll, or a bot. *plonk* Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Can one get for x in y to work for non builtin classes?
On Mon, 03 Mar 2008 12:17:39 +0100, M.-A. Lemburg wrote: It's also possible to implement .__getitem__() and .__len__() methods and have Python create an iterator on-the-fly. That's how Python used to work before iterators were added to the language. A suitable `__getitem__()` is enough. The end will be signaled by an `IndexError`. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: help needed with regex and unicode
On Tue, 04 Mar 2008 10:49:54 +0530, Pradnyesh Sawant wrote:
I have a file which contains chinese characters. I just want to find out
all the places that these chinese characters occur.
The following script doesn't seem to work :(
**
class RemCh(object):
def __init__(self, fName):
self.pattern = re.compile(r'[\u2F00-\u2FDF]+')
fp = open(fName, 'r')
content = fp.read()
s = re.search('[\u2F00-\u2fdf]', content, re.U)
if s:
print s.group(0)
if __name__ == '__main__':
rc = RemCh('/home/pradnyesh/removeChinese/delFolder.php')
**
the php file content is something like the following:
**
// Check if the folder still has subscribed blogs
$subCount = function1($param1, $param2);
if ($subCount 0) {
$errors['summary'] = 'æÂï½ æ½å¤æ¤Ã¥Ã¯Â«Ã¥Ã©Ã©Â§Ã§Â²Ã¨';
$errorMessage = 'æÂï½ æ½å¤æ¤Ã¥Ã¯Â«Ã¥Ã©Ã©Â§Ã§Â²Ã¨';
}
Looks like an UTF-8 encoded file viewed as ISO-8859-1. Sou you should
decode `content` to unicode before searching the chinese characters.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: First post from a Python newbiw
On Sun, 02 Mar 2008 14:15:09 +, Steve Turner wrote: Apart from doing something like a=[0,0,0] b=[0,0,0] c=[0,0,0] d=[a,b,c] is there a better way of creating d?? a = [[0] * 3 for dummy in xrange(3)] Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: First post from a Python newbiw
On Sun, 02 Mar 2008 21:58:31 +0100, Christoph Zwerschke wrote: Marc 'BlackJack' Rintsch schrieb: On Sun, 02 Mar 2008 14:15:09 +, Steve Turner wrote: Apart from doing something like a=[0,0,0] b=[0,0,0] c=[0,0,0] d=[a,b,c] is there a better way of creating d?? a = [[0] * 3 for dummy in xrange(3)] Why not simply [[0]*3]*3 ? Because: In [77]: a = [[0] * 3] * 3 In [78]: a Out[78]: [[0, 0, 0], [0, 0, 0], [0, 0, 0]] In [79]: a[0][0] = 42 In [80]: a Out[80]: [[42, 0, 0], [42, 0, 0], [42, 0, 0]] Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Is it possible to return a variable and use it...?
On Sun, 02 Mar 2008 20:15:10 -0800, Nathan Pinno wrote: Hello all, Is it possible to return a variable and then use it like the following: [code] dir exp_1: while hen != * sum = sum + hen return sum dir exp_2: if sum = total_needed: print Profit can be made. else: print Expect a loss. total_needed = int(raw_input(What is the total eggs needed? )) hen = int(raw_input(How many eggs did each hen lay? Enter them in 1 by 1 or enter * when done. )) exp_1 exp_2 [/code] If not, then how do I do so? Please work through the tutorial, then try to write actual Python code and come back if you have problems with your implementation of the program. Show us the real code and a description of either what error message you get, with full traceback, or if it does not raise an exception but just does not what you excpect it to do, tell us what you expected and what you get instead. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Character Problem
On Mon, 03 Mar 2008 04:27:52 +0200, Harun BAYKAL wrote: I am studying on an addon developed for QGIS, a GIS software. But I have a problem. The extension has been developed with QT and Python. Actually Python is used for the interface design. For the user interface Python reads some values from some database files. I am not experienced Python user and the first developer of the addon had written the python codes for his database. And his database doesn't include any characters than the usual characaters. But my database file contains many characters which are not used in English. So I can not compile the extension because Python can not read the database files. So how can I change the python files for making it to read the databases without modifying the database. Otherwise I had to clear all the non usual characters from the database file which means most of the names and strings will be wrong. So somehow I had to make the python files to read the other unicode and non english characters? Anybody have any idea about how I can I fix such a problem. All I get from this description is, that you have a problem with encodings but what is the *specific* problem? Where does the program fail? With what exception(s)? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: How about adding rational fraction to Python?
On Fri, 29 Feb 2008 17:29:32 -0800, Lie wrote: On Feb 28, 10:00 am, Paul Rubin http://[EMAIL PROTECTED] wrote: More examples: x = 1 y = len(s) + x = ok, decides that x is an int x = 1 y = x + 3.0 = ok, decides that x is a float x = 1 y = x + 3.0 z = len(s) + x = forbidden, x cannot be an int and float at the same time. I am so glad you're not the designer of Python. This is how Haskell works and I don't notice much complaints about it. Ok, that means the line y = x + 3.0 have a side effect of x = float(x)? I think I would say that is an implicit behavior. But the type of `x` must be specialized somehow. `x` doesn't start as `Int` or `Integer` but the very generic and AFAIK abstract type class `Num`. After seeing the second line the compiler finds an implementation for `+` and the type class `Fractional` for both operands and now thinks `x` must be a `Fractional`, a subclass of `Num`. Then comes the third line with `length` returning an `Int` and the `Fractional` `x` but there is no implementation for a `+` function on those types. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: mod_python Unable to create file
On Sat, 01 Mar 2008 22:47:02 -0800, kaush wrote: I am using Apache and mod_python to service POST/GET requests on MAC OS. My script tries to create a file file = open(file_path, 'w') This fails with the following error EACCES Permission denied What is missing? To state the ovious: the rights to create a file at `file_path`. Remember that web servers usually have their own user. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythons Ladders
On Thu, 28 Feb 2008 10:34:45 -0800, Jeff Schwab wrote: Hey a flame bait. I'll bite. Excuse me? Somebody posts about an introductory course on C++ covering dynamic arrays using pointers and literally says kill me now, and I'm the flamer for asking him not to hold the language responsible for the bad course? This a bit of an overreaction unless you know what the course was about. It's supposed to be about C++, according to the OP. Yeah, sorry I've read C. Actually it's about a language called C ++ according to the OP. To the OP: If you try C++, don't hold that crappy language against C#, D, or Java. ;-) What's the relevance of C#, D, or Java to the OP's post? The same as C++ to the OP's post if he would have talked about C. :-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: XML expat error
On Thu, 28 Feb 2008 12:37:10 -0800, dirkheld wrote: Yes of course: handle the exception instead of letting it propagate to the top level and ending the program. Ehm, maybe a stupid question... how. I'm rather new to python and I never user error handling. Then you should work through the tutorial in the docs, at least until section 8.3 Handling Exceptions: http://docs.python.org/tut/node10.html#SECTION001030 Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythons Ladders
On Wed, 27 Feb 2008 19:18:27 -0800, Jeff Schwab wrote: Benoit wrote: I've been teaching myself the python language over the past few months using Mark Lutz' Learning Python, 3ed. Python is also the first programming language I've ever taken up. I find the language easy to learn and rather productive in relation to the introductory course on C ++ I'd begun in January for fun @ school (we're practicing dynamic arrays using pointers... kill me now). Get a better teacher, if you can. Please do me a personal favor: Don't hold the crappy course against C++. For the record, you should never have to manage dynamically allocated arrays manually, nor store pointers to them. Try the std::vector template, and post in comp.lang.c++ if have any trouble. Hey a flame bait. I'll bite. This a bit of an overreaction unless you know what the course was about. If the goal is to learn about the computer and that basically everything is a number in the end, then C is a good choice. More portable than assembler but nearly as close to the metal. To the OP: If you try C++, don't hold that crappy language against C#, D, or Java. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: XML expat error
On Wed, 27 Feb 2008 14:02:25 -0800, dirkheld wrote: Something strange here. The xml file causing the problem has only 361 lines. Isn't there a way to catch this error, ignore it and continu with the rest of the other files? Yes of course: handle the exception instead of letting it propagate to the top level and ending the program. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: How about adding rational fraction to Python?
On Wed, 27 Feb 2008 19:00:19 -0800, Paul Rubin wrote:
Steven D'Aprano [EMAIL PROTECTED] writes:
Okay, that's just insane, making distinctions between literals and
variables like that.
1 + 1.0 # okay
= Yes
x = 1
x + 1.0 # is this okay or not? who knows?
= Yes, ok
len('s') + 1.0 # forbidden
Yes, forbidden.
More examples:
x = 1
y = len(s) + x
= ok, decides that x is an int
x = 1
y = x + 3.0
= ok, decides that x is a float
x = 1
y = x + 3.0
z = len(s) + x
= forbidden, x cannot be an int and float at the same time.
I am so glad you're not the designer of Python.
This is how Haskell works and I don't notice much complaints about it.
Complain! :-)
For implementing this in Python you have to carry an is allowed to be
coerced to float flag with every integer object to decide at run time if
it is an error to add it to a float or not. Or you make Python into a
statically typed language like Haskell. But then it's not Python anymore
IMHO.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: dict.get and str.xsplit
On Tue, 26 Feb 2008 06:02:12 -0800, bearophileHUGS wrote: This is a real difference, that has real impact on the programs I write, so I often use the if/else approach, despite the dict.get() method being semantically fitter and shorter. So can the dict.get() method be speed up? And if not, why? I guess it's the method lookup that's the slow part. Factor it out of the loop and measure again:: adict_get = adict.get for _ in xrange(M): for k in keys1: r = adict_get(k, None) for k in keys2: r = adict_get(k, None) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Article of interest: Python pros/cons for the enterprise
On Tue, 26 Feb 2008 05:23:11 -0800, Nicola Musatti wrote: At least in C++ resource management only becomes more complicated if you need more control. I think this is the point where so many people here disagree. I'm coming from a garbage collection background in OOP programming. In C++ resource management becomes instantly more complicated because I have to think about memory management and must actively manage it in *every case*. Writing code in a RAII style and using smart pointer templates is a cost for me. A cost that's quite high, because it feels completely wrong to have to think about it and to write in that value style, because that goes against my expectations/picture of OOP -- a graph of independent/loosely coupled objects communicating with each other. In this sense C++ looks like a quite crippled and fragile OOP language to me. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: How about adding rational fraction to Python?
On Tue, 26 Feb 2008 04:29:18 -0800, Lie wrote: J Cliff Dyer: I'm in the camp that believes that 3/4 does indeed yield the integer 0, but should be spelled 3//4 when that is the intention. That's creepy for people that are new to programming and doesn't know how CPUs work and are used to general mathematics. That means most people. As programming language are now more accessible to regular people without specialized Computer Science degree, it is a just natural trend that computer arithmetic must be done in an expectable manner as seen by those general population not by people who holds a CS degree. So why is it creepy then!? ``3 // 4`` is for the people knowing about integer division and ``3 / 4`` gives the expected result for those who don't. Those who don't know ``//`` can write ``int(3 / 4)`` to get the same effect. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: dict.get and str.xsplit
On Tue, 26 Feb 2008 06:33:01 -0800, castironpi wrote: On Feb 26, 8:14 am, Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote: On Tue, 26 Feb 2008 06:02:12 -0800, bearophileHUGS wrote: This is a real difference, that has real impact on the programs I write, so I often use the if/else approach, despite the dict.get() method being semantically fitter and shorter. So can the dict.get() method be speed up? And if not, why? I guess it's the method lookup that's the slow part. Factor it out of the loop and measure again:: adict_get = adict.get for _ in xrange(M): for k in keys1: r = adict_get(k, None) for k in keys2: r = adict_get(k, None) Ciao, Marc 'BlackJack' Rintsch Can't be. The string 'get' is only hashed once, since it's hard-coded into the script, and looking it up can't be any slower than looking up __getitem__. Within functions it is faster. In the original code the `get` attribute is looked up on the `adict` object twice in each loop iteration via hashing. In my code it is looked up once before the loop and within the loop the local name `adict_get` isn't looked up but hardcoded as index into the internal locals array of the function. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: How about adding rational fraction to Python?
On Tue, 26 Feb 2008 09:29:55 -0500, D'Arcy J.M. Cain wrote: If 3/4 ever returned 0.75 in any language I would drop that language. Then prepare to drop Python from version 3 on: Python 3.0a1 (py3k, Aug 31 2007, 21:20:42) [GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2 Type help, copyright, credits or license for more information. 3 / 4 0.75 Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: is there enough information?
On Tue, 26 Feb 2008 09:13:35 -0800, castironpi wrote: Back home, the original post would be interesting, so I wrote it. So you think of this group as your personal notepad. That explains a lot. :-/ Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Return value of an assignment statement?
On Sat, 23 Feb 2008 22:44:30 +, Tim Roberts wrote: Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote: On Fri, 22 Feb 2008 11:00:17 -0800, Aahz wrote: It's just too convenient to be able to write L += ['foo'] without rebinding L. nitpickBut ``+=`` does rebind./nitpick Usually, but there's an exception for lists, which a specific implementation for += that calls append. Or do I misunderstand you? Terry Reedy showed the tuple proof, here's the read only property case:: class A(object): def __init__(self): self._data = list() @property def data(self): return self._data a = A() a.data += [42] Output:: Traceback (most recent call last): File test.py, line 25, in module a.data += [42] AttributeError: can't set attribute Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Return value of an assignment statement?
On Fri, 22 Feb 2008 11:00:17 -0800, Aahz wrote: It's just too convenient to be able to write L += ['foo'] without rebinding L. nitpickBut ``+=`` does rebind./nitpick Doesn't matter in this case but we've had confused programmers asking questions here when `L` is a class attribute and it's rebound to the instance, or if they tried it on a list in a tuple. Extending a list that's a read only property doesn't work either. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple - looking for a way to do an element exists check..
On Sat, 23 Feb 2008 17:19:47 -0800, thebjorn wrote: On Feb 23, 6:18 pm, Paul Hankin [EMAIL PROTECTED] wrote: IMO Jason's solution of testing containment in a generator is better (more readable). if element[0] not in (x[0] for x in a): a.append(element) It may be more readable (although that's debatable), but it always traverses the entire list. The ``not in`` stops if the element is found. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Return value of an assignment statement?
On Thu, 21 Feb 2008 21:28:25 -0800, Jeff Schwab wrote: So what is the variable? Or is Python the first HLL I've ever heard of that didn't have variables? Relax, Python has variables. It's just sometimes a good advice for people coming from languages like C to forget about that term for a while because they have the wrong impression of what variable means. A variable in programming languages is composed of a name, a memory location, possibly a type and a value. In C-like languages, where you put values in named and typed boxes, the memory location and type are attached to the name. In Python both belong to the value. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Acting like button are being pressed (BUT THEY ARE NOT) Please Help
On Fri, 22 Feb 2008 06:48:37 -0800, mcsejung wrote: [snipped massive bit of code] Sorry but dumping about 900 lines of code at people with no real question in the message body and just sort of a question in the subject won't help much to get answers. Just a quick look at the code tells that it could use some loops to refactor it into a **much** shorter piece of code. Then get rid of the asterisk import, ``except``\s without a specific exception to handle, and the``global`` statement before you repost the problem. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Getting python docstings
On Fri, 22 Feb 2008 03:53:27 -0800, Rufman wrote: On Feb 22, 10:36 am, Stefan Behnel [EMAIL PROTECTED] wrote: Rufman wrote: Does anyone know how to get docstrings (reStructuredText) out of python source code using docutils? Depends on what you mean with get ... out of. There are tools like epydoc that generate source code documentation, maybe that's what you mean? Yeah...something like that, but using docutils. What is something like that? If `epydoc` doesn't do what you want, then *what* exactly *do* you want? You know that `epydoc` supports reStructuredText as markup language!? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Return value of an assignment statement?
On Fri, 22 Feb 2008 12:32:10 +, Steven D'Aprano wrote: On Fri, 22 Feb 2008 08:12:56 +, Marc 'BlackJack' Rintsch wrote: A variable in programming languages is composed of a name, a memory location, possibly a type and a value. In C-like languages, where you put values in named and typed boxes, the memory location and type are attached to the name. In Python both belong to the value. But Python objects don't have names, so by your own definition, they aren't variables. Exactly! Names aren't variables. The unit of a name, an address, and a value are a variable. Names are associated with namespaces, not objects. A name must have one and only one object bound to it at any one time; What is a binding when it's not an association between a name and an object!? So names are associated with objects. There are no names without objects in Python. If a name is not bound to any object, how could the name exist? That would be like a dangling pointer, a beast that doesn't exists in Python. nitpickOkay there are local names that are known and therefore somehow exist before they get bound, but that's IMHO an implementation detail.nitpick objects on the other hand can be bound to one name, or no name, or a thousand names. The object itself has no way of knowing what names it is bound to, if any. Or, to put it another way... Python doesn't have variables. It has. You just can't substitute the term name with variable and expect it to behave like in C. A variable is not just the name but also the value and the storage space and how those are connected. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Article of interest: Python pros/cons for the enterprise
On Fri, 22 Feb 2008 04:48:28 -0800, Nicola Musatti wrote:
On Feb 22, 12:07 pm, Paul Rubin http://[EMAIL PROTECTED] wrote:
Nicola Musatti [EMAIL PROTECTED] writes:
In C++ memory is just another resource which you can handle just like
any other one, possibly using RAII.
Ok, I'll bite. Here's a straightforward Python expression:
a = [f(x) + g(y) for x,y in izip(m1, m2) if h(x,y).frob() == 7]
Consider how many intermediate objects are being allocated in figuring
out that listcomp. Do you REALLY want to manage all the deallocation
with something like RAII?
What makes you think that a translation of a similar expression would
involve explicit dynamic allocation at all? Barring bugs, here's an
equivalent example:
#include iostream
#include map
#include vector
int f(int n) { return n * 2; }
int g(int n) { return ( n * 2 ) + 1; }
std::mapint, int izip(int i, int j) {
std::mapint, int m;
m[i] = j;
m[j] = i;
return m;
}
class A {
int i, j;
public:
A(int ii, int jj) : i(ii), j(jj) {}
int frob() { return i + j; }
};
A h(int i, int j) { return A(i, j); }
int main() {
int m1 = 3;
int m2 = 4;
std::vectorint a;
std::mapint, int m = izip(m1, m2);
for ( std::mapint,int::iterator i = m.begin(); i != m.end(); ++i )
{
if ( h(i-first, i-second).frob() == 7 )
a.push_back(f(i-first) + g(i-second));
}
for ( std::vectorint::iterator i = a.begin(); i != a.end(); ++i )
std::cout *i '\n';
}
As you can see the standard library takes care of all memory
management.
Aaah, that's much nicer and easier to understand than the list
comprehension. After this great example I'll switch to C++. ;-)
But somehow you still manage memory by writing in a style that favors
value types.
SCNR,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: What's the standard for code docs?
On Tue, 19 Feb 2008 16:37:23 -0800, Preston Landers wrote: On Feb 19, 4:31 pm, [EMAIL PROTECTED] wrote: But after reading some of your other recent posts on other topics, I'm not confident that it was intended to make sense at all. Have a little bit patience, the bot is still in its early learning phase. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter Confusion
On Sun, 17 Feb 2008 11:36:25 -0800, MartinRinehart wrote: Everything I've read about Tkinter says you create your window and then call its mainloop() method. But that's not really true. This is enough to launch a default window from the console: from Tkinter import * foo = Tk() Depends on the platform if this shows a window. Do I use Tk() or toplevel()? (Support for both and if a cogent explanation of the differences exists, I didn't find it.) `Tk` is the main window, `Toplevel` for additional windows. Don't create several `Tk` instances. That usually causes very weird side effects. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: a question in python curses modules
On Fri, 15 Feb 2008 11:55:11 +0800, Marco wrote: Hi, I wanna write a simple curses program, but somethings confuse me, my code here: #!/usr/bin/python import os import sys import time import curses class CursesObject( object ): def __init__(self): self.STDSCR = curses.initscr() curses.noecho() curses.cbreak() self.STDSCR.keypad(1) def __del__(self): self.STDSCR.keypad(0) curses.nocbreak() curses.echo() curses.endwin() c1 = CursesObject() time.sleep(1) I donot know what happen, but in __del__ function, curses become None??!! When the interpreter shuts down it has to remove objects. Everything you need in a `__del__()` method must be referenced by that object to be sure that it is still there and not already garbage collected. *But* it's not guaranteed that `__del__()` is called at all! So if you think this clean up is necessary to leave a usable console then don't put it into a `__del__()` method! Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: a question in python curses modules
On Fri, 15 Feb 2008 15:10:12 +, Sion Arrowsmith wrote: Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote: When the interpreter shuts down it has to remove objects. Everything you need in a `__del__()` method must be referenced by that object to be sure that it is still there and not already garbage collected. *But* it's not guaranteed that `__del__()` is called at all! This may be true, but it's not really the point here, since clearly __del__() *is* being called, otherwise how would the OP know that curses was None in it? It's not the point the OP asked for directly but just the answer in the first two sentences might have left the impression it's okay to use `__del__()` for this kind of clean up if you make sure that `curses` is bound to the object. Then it may appear to work for the OP but it's not guaranteed to work under all circumstances. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: fromfunc functions
On Wed, 13 Feb 2008 07:51:36 -0800, azrael wrote: I came across the fromfunc() function in numpy where you pass as an argument the name of a function as a string and also the atributes for the desired function. If you mean `fromfunction()` then you don't give the name of the function as string but the function itself as argument. And what you call attributes are arguments. I find this extremly usefull and sexy. Can someone point me how write a function of such capabilities Functions are objects in Python, you can pass them around like any other object/value. In [18]: def f(func, arg): : return func(arg) : In [19]: f(int, '42') Out[19]: 42 In [20]: f(str.split, 'a b c') Out[20]: ['a', 'b', 'c'] Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: ways to declare empty set variable
On Tue, 12 Feb 2008 14:45:43 +0100, Sun wrote: then the question is how can I declare a empty set variable as a 'var= []' do to a list variable? You don't declare variables in Python. Just create an instance of `set` and bind it to a name: var = set() Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: __builtins__
On Fri, 08 Feb 2008 00:25:14 -0800, loquehumaine wrote: I have seen that if I type help() at a prompt, and then 'modules', I'll be given a list of all modules available, thanks to this group.. But I have seen the differences between them and the one in dir(__builtins__). Why are some modules in __builtins__ and others don't ? (UserDict for example) `__builtins__` doesn't contain modules:: Python 2.4.4 (#2, Apr 12 2007, 21:03:11) [GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2 Type help, copyright, credits or license for more information. import inspect inspect.getmembers(__builtins__, inspect.ismodule) [] Why dir(__builtins__) gives me math but not help(__builtins__) ? So there's no 'math' in `__builtins__`:: 'math' in dir(__builtins__) False What are the differences between __builtins__ and __builtin__ ? (By the way, I have python 2.4) `__builtins__` is an implementation detail, and `__builtin__` is a name of a module you can import. You should not use `__builtins__` but import `__builtin__` and inspect that instead of `__builtins__`. The (symmetric) difference of the two is empty:: import __builtin__ set(dir(__builtins__)).symmetric_difference(dir(__builtin__)) set([]) Finally, if I do del(__builtins__), what can I do to repair the mistake (as I got an import error __import__ not found if I want to import __builtins__...? Don't ``del __builtins__`` in the first place. :-) That's may be obvious for you, but that's all strange to me and I didn't find answers on the net... So the real question is, why you see 'math' in `__builtins__`. It should not be there. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Why not a Python compiler?
On Fri, 08 Feb 2008 17:45:36 +, Grant Edwards wrote: On 2008-02-08, Arnaud Delobelle [EMAIL PROTECTED] wrote: Please get back on topic. This discussion is about parsecs and wookies now. What's a wookie a unit of? The degree of confusion among the jury when using the Chewbacca defense. :-) http://en.wikipedia.org/wiki/Chewbacca_defense Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Why not a Python compiler?
On Fri, 08 Feb 2008 05:12:29 -0800, Ryszard Szopa wrote: Expressing simple loops as C for loops... You mean simple loops like ``for i in xrange(1000):``? How should the compiler know what object is bound to the name `xrange` when that loop is executed? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: beginner question, function returning object.
On Thu, 07 Feb 2008 19:14:54 +1100, bambam wrote: I started with ths: -- def open_pipe(): pipe=PIPE() print pipe return pipe pipe=open_pipe() pipe.parent = self.parent print pipe -- It didn't do what I wanted: when I printed the pipe the second time it was not the same object as the first time. Please post actual minimal code that reproduces the problem and a better description of what you get and what you expected instead. What is `PIPE` and where does `self` come from? What are the too ``print``\s printing that makes you think `pipe` isn't bound to the same object? So I changed it to this: def open_pipe(pipe): pipe=PIPE() print pipe pipe = None open_pipe(pipe) pipe.parent = self.parent print pipe It still doesn't do what I wanted: I can't assign the parent property because pipe type is None. Yes because in `open_pipe()` you bind a new object to the local name `pipe` which of course has no effect on the binding of the name `pipe` in the callers namespace. I'm not sure enough of what I am doing to tell if I have another error in my code causing the problem. Is either of these examples supposed to work as shown? Is it clear that either example is obviously wrong? The second is wrong. The first should work if `self` and `PIPE` are bound to appropriate objects. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: getting all user defined attributes of a class
On Wed, 06 Feb 2008 14:07:23 -0800, Amit Gupta wrote: Class A(object) : self.x = 1 This is not valid Python code. I want something like: for userattrib in A.getAllUserAttribute() : print userattrib My question is, is there a builtin function, called getAllUserAttributes? No and there can't be since the attributes you seem to be interested in don't exist until an instance is created. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: getting all user defined attributes of a class
On Wed, 06 Feb 2008 15:16:26 -0800, Amit Gupta wrote:
On Feb 6, 2:55 pm, Diez B. Roggisch [EMAIL PROTECTED] wrote:
Amit Gupta schrieb:
I should make class A as:
class A (object) :
x = 1
Now, x is class attribute and I am looking for some-way to filter non-
user-defined attributes.
e.g.g if I do
for attr in a.__dict__ :
print attr
I will also get
__module__, __weakref__ and others including x
Just create an empty class, gather all attribute names from that and
then subtract that set of names from the names you get from a real class.
Dize
Fine. This is a hack. I am looking if python language itself provides
any built-in function for this. E.g.:
Why is that a hack!? What about:
In [369]: def is_special_name(name):
.: return name.startswith('__') and name.endswith('__')
.:
In [370]: filter(lambda m: not is_special_name(m[0]), inspect.getmembers(A))
Out[370]: [('x', 1)]
When I do help on some built-in function, it displays that function is
built_in. Can that information get accessed using a function? (now,
don't ask me to store help-output in buffer and grep for built-in).
Yes but it is not built-in. Have a look at the `inspect` module.
What's the use case?
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Elementary string-parsing
On Tue, 05 Feb 2008 06:19:12 +, Odysseus wrote:
In article [EMAIL PROTECTED],
Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
Another issue is testing. If you rely on global names it's harder to test
individual functions. [...]
In programs without such global names you see quite clearly in the
``def`` line what the function expects as input.
Good points, although thorough commenting can go a long way to help on
both counts. In theory, at least ...
Won't work in practice so well. Say we have function `f()` and
document that it expects global name `a` to be set to something before
calling it. `f()` is used by other functions so we have to document `a` in
all other functions too. If we change `f()` to rely on global name `b`
too we have to hunt down every function that calls `f()` and add the
documentation for `b` there too. It's much work and error prone. Easy to
get inconsistent or missing documentation this way.
To write or check documentation for a function you have to scan the whole
function body for data in global names and calls to other functions and
repeat the search there. If you don't let functions communicate via global
names you just have to look at the argument list to see the input sources.
def main():
# Main program comes here.
if __name__ == '__main__':
main()
Then main is called when the script is called as program, but not called if
you just import the script as module. For example to test functions or to
reuse the code from other scripts.
I'm using if __name__ == 'main' now, but only for test inputs (which
will eventually be read from a config file or passed by the calling
script -- or something). I hadn't thought of putting code that actually
does something there. As for writing modules, that's way beyond where I
want to go at this point: I don't know any C and am not sure I would
want to ...
What does this have to do with C!? There's no specific C knowledge
involved here.
assert name.startswith('Name: ')
It checks if `name` really starts with 'Name: '. This way I turned the
comment into code that checks the assertion in the comment.
Good idea to check, although this is actually only one of many
assumptions I make about the data -- but what happens if the assertion
fails? The program stops and the interpreter reports an AssertionError
on line whatever?
Yes, you get an `AssertionError`:
In [314]: assert True
In [315]: assert False
---
type 'exceptions.AssertionError'Traceback (most recent call last)
/home/bj/ipython console in module()
type 'exceptions.AssertionError':
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Elementary string-parsing
On Mon, 04 Feb 2008 09:43:04 +, Odysseus wrote:
In article [EMAIL PROTECTED],
Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
def extract_data(names, na, cells):
found = dict()
The problem with initializing the 'super-dictionary' within this
function is that I want to be able to add to it in further passes, with
a new set of names cells each time.
Then you can either pass in `found` as argument instead of creating it
here, or you collect the passes in the calling code with the `update()`
method of `dict`. Something like this:
found = dict()
for pass in passes:
# ...
found.update(extract_data(names, na, cells))
BTW what's the difference between the above and found = {}?
I find it more explicit. ``dict`` and ``list`` are easier to
distinguish than ``{}`` and ``[]`` after a lng coding session or when
printed/displayed in a small font. It's just a matter of taste.
for i, name in enumerate(names):
data = dict()
cells_index = 10 * i + na
for cell_name, index, parse in (('epoch1', 0, parse_date),
('epoch2', 1, parse_date),
('time', 5, parse_number),
('score1', 6, parse_number),
('score2', 7, parse_number)):
data[cell_name] = parse(cells[cells_index + index])
This looks a lot more efficient than my version, but what about the
strings that don't need parsing? Would it be better to define a
'pass-through' function that just returns its input, so they can be
handled by the same loop, or to handle them separately with another loop?
I'd handle them in the same loop. A pass-through function for strings
already exists:
In [255]: str('hello')
Out[255]: 'hello'
assert name.startswith('Name: ')
I looked up assert, but all I could find relates to debugging. Not
that I think debugging is something I can do without ;) but I don't
understand what this line does.
It checks if `name` really starts with 'Name: '. This way I turned the
comment into code that checks the assertion in the comment.
The `parse_number()` function could look like this:
def parse_number(string):
try:
return float(string.replace(',', ''))
except ValueError:
return string
Indeed the commas can be replaced a bit more elegant. :-)
Nice, but I'm somewhat intimidated by the whole concept of
exception-handling (among others). How do you know to expect a
ValueError if the string isn't a representation of a number?
Experience. I just tried what happens if I feed `float()` with a string
that is no number:
In [256]: float('abc')
---
type 'exceptions.ValueError'Traceback (most recent call last)
/home/bj/ipython console in module()
type 'exceptions.ValueError': invalid literal for float(): abc
Is there a list of common exceptions somewhere? (Searching for
ValueError turned up hundreds of passing mentions, but I couldn't find
a definition or explanation.)
The definition is quite vague. The type of an argument is correct, but
there's something wrong with the value.
See http://docs.python.org/lib/module-exceptions.html for an overview of
the built in exceptions.
As already said, that ``while`` loop should be a ``for`` loop. But if
you put `m_abbrevs` into a `list` you can replace the loop with a
single call to its `index()` method: ``dlist[1] =
m_abbrevs.index(dlist[1]) + 1``.
I had gathered that lists shouldn't be used for storing constants. Is
that more of a suggestion than a rule?
Some suggest this. Others say tuples are for data where the position of
an element has a meaning and lists are for elements that all have the
same meaning for some definition of meaning. As an example ('John',
'Doe', 'Dr.') vs. ['Peter', 'Paul', 'Mary']. In the first example we have
name, surname, title and in the second example all elements are just
names. Unless the second example models a relation like child, father,
mother, or something like that. Anyway, if you can make the source simpler
and easier to understand by using the `index()` method, use a list. :-)
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected timing results with file I/O
On Mon, 04 Feb 2008 10:48:32 -0800, rdahlstrom wrote: It doesn't matter how many doors opening and closing there are, it matters the order in which the opening, walking through, and closing are done. That's my point. In the second example, all of the disk operations are done at the same time. That's what I meant by people going through the doors. Maybe it was more clear in my head. But my timing shows that method two is slower on my computer. So there is no obvious winner. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected timing results with file I/O
On Mon, 04 Feb 2008 15:17:18 +, Steven D'Aprano wrote: # Method one: grouped by file. for each file: open the file, append the string, then close it # Method two: grouped by procedure. for each file: open the file for each open file: append the string for each open file: close the file Method 1: 17.391216039657593 Method 2: 16.823362112045288 Surprisingly, Method 2 is a smidgen faster, by about half a second over 500,000 open-write-close cycles. It's not much faster, but it's consistent, over many tests, changing many of the parameters (e.g. the number of files, the number of runs per timeit test, etc.). I'm using Linux and Python 2.5. So, what's going on? Can anyone explain why the code which does more work takes less time? Can't confirm this (Linux, Python 2.5): Method 1: 15.380897998809814 Method 2: 18.085366010665894 I guess it's really all about the disk IO as my system monitor applet shows that almost all of the time is spend in the kernel and very little in user space. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Elementary string-parsing
On Mon, 04 Feb 2008 12:25:24 +, Odysseus wrote: I'm not clear on what makes an object global, other than appearing as an operand of a global statement, which I don't use anywhere. But na is assigned its value in the program body, not within any function: does that make it global? Yes. The term global usually means module global in Python. Why is this not recommended? Because the functions depend on some magic data coming from nowhere and it's much harder to follow the data flow in a program. If you work with globals you can't be sure what the following will print: def spam(): global x x = 42 beep() print x `beep()` might change `x` or any function called by `beep()` and so on. Another issue is testing. If you rely on global names it's harder to test individual functions. If I want to test your `extract_data()` I first have to look through the whole function body and search all the global references and bind those names to values before I can call the function. This might not be enough, any function called by `extract_data()` might need some global assignments too. This way you'll get quite soon to a point where the single parts of a program can't be tested in isolation and are not reusable for other programs. In programs without such global names you see quite clearly in the ``def`` line what the function expects as input. If I wrap the assignment in a function, making na a local variable, how can extract_data then access it? Give it as an argument. As a rule of thumb values should enter a function as arguments and leave it as return values. It's easy to enforce if you have minimal code on the module level. The usual idiom is: def main(): # Main program comes here. if __name__ == '__main__': main() Then main is called when the script is called as program, but not called if you just import the script as module. For example to test functions or to reuse the code from other scripts. def extract_data(names, na, cells): and return something What should it return? A Boolean indicating success or failure? All the data I want should all have been stored in the found dictionary by the time the function finishes traversing the list of names. Then create the `found` dictionary in that function and return it at the end. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected timing results with file I/O
On Mon, 04 Feb 2008 10:18:39 -0800, rdahlstrom wrote: On Feb 4, 1:12 pm, Carl Banks [EMAIL PROTECTED] wrote: On Feb 4, 12:53 pm, rdahlstrom [EMAIL PROTECTED] wrote: You have 500,000 people to fit through a door. Here are your options: 1. For each person, open the door, walk through the door, then close the door. 2. Open the door, allow everyone to walk through, then close the door. Which one would you say would be a more efficient way to fit 500,000 people through the door? Bad analogy. A better analogy would be if each person has their own door to walk through. The analogy holds. It's faster to open the door, do what you need to do, then close the door than it is to open and close the door each time. It doesn't hold. Read the code again. The total count of open door and close door is the same in both cases. It's for every person: open his door; push him through the door; close his door vs. for every person: open his door for every person: push him through the door for every person: close his door Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: future multi-threading for-loops
On Mon, 04 Feb 2008 19:22:29 -0800, castironpi wrote: Some iterables and control loops can be multithreaded. Worries that it takes a syntax change. for X in A: def f( x ): normal suite( x ) start_new_thread( target= f, args= ( X, ) ) Perhaps a control-flow wrapper, or method on iterable. @parallel for X in A: normal suite( X ) for X in parallel( A ): normal suite( X ) Discussion presued about multi-core systems. Allow user certain control over what runs on multi-core. Clearly, not generally applicable. -- But, from __future__ import does change syntax. Why not simply writing a function? def execute_parallel(f, A): for args in A: start_new_thread(target=f, args=args) def f(x): normal_suit(x) parallel(f, A) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: extending python with array functions
On Mon, 04 Feb 2008 20:56:02 -0200, Gabriel Genellina wrote: - the array module http://docs.python.org/lib/module-array.html provides homogeneuos arrays that may be more efficient for your application. arrays don't have a special API, you have to import the module and use its functions the same as one would do in pure Python. There's one special thing about it: the `buffer_info()` method returns a tuple with the memory address and length (in items) of the current underlying buffer. Pretty useless information in Python but handy in extensions that can directly access the raw memory. To the OP: Since Python 2.5 the `ctypes` module is another way to interface with native code in dynamic libraries from the standard library. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected timing results with file I/O
On Mon, 04 Feb 2008 21:58:46 +, Steven D'Aprano wrote: On Mon, 04 Feb 2008 17:08:02 +, Marc 'BlackJack' Rintsch wrote: Surprisingly, Method 2 is a smidgen faster, by about half a second over 500,000 open-write-close cycles. It's not much faster, but it's consistent, over many tests, changing many of the parameters (e.g. the number of files, the number of runs per timeit test, etc.). I'm using Linux and Python 2.5. So, what's going on? Can anyone explain why the code which does more work takes less time? Can't confirm this (Linux, Python 2.5): Method 1: 15.380897998809814 Method 2: 18.085366010665894 Hmmm... does your system use software RAID? Mine does. I wonder if that's a relevant factor? No, test ran on a plain reiserfs partition. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Elementary string-parsing
On Mon, 04 Feb 2008 03:21:18 +, Odysseus wrote:
def extract_data():
i = 0
while i len(names):
name = names[i][6:] # strip off Name:
found[name] = {'epoch1': cells[10 * i + na],
'epoch2': cells[10 * i + na + 1],
'time': cells[10 * i + na + 5],
'score1': cells[10 * i + na + 6],
'score2': cells[10 * i + na + 7]}
Here and in later code you use a ``while`` loop although it is known at
loop start how many times the loop body will be executed. That's a job
for a ``for`` loop. If possible not over an integer that is used later
just as index into list, but the list itself. Here you need both, index
and objects from `names`. There's the `enumerate()` function for creating
an iterable of (index, name) from `names`.
I'd put all the relevant information that describes a field of the
dictionary that is put into `found` into tuples and loop over it. There
is the cell name, the index of the cell and function that converts the
string from that cell into an object that is stored in the dictionary.
This leads to (untestet):
def extract_data(names, na, cells):
found = dict()
for i, name in enumerate(names):
data = dict()
cells_index = 10 * i + na
for cell_name, index, parse in (('epoch1', 0, parse_date),
('epoch2', 1, parse_date),
('time', 5, parse_number),
('score1', 6, parse_number),
('score2', 7, parse_number)):
data[cell_name] = parse(cells[cells_index + index])
assert name.startswith('Name: ')
found[name[6:]] = data
return found
The `parse_number()` function could look like this:
def parse_number(string):
try:
return float(string.replace(',', ''))
except ValueError:
return string
Indeed the commas can be replaced a bit more elegant. :-)
`parse_date()` is left as an exercise for the reader.
for k in ('epoch1', 'epoch2'):
dlist = found[name][k].split( )
m = 0
while m 12:
if m_abbrevs[m] == dlist[1]:
dlist[1] = m + 1
break
m += 1
tlist = dlist[3].split(:)
found[name][k] = timegm((int(dlist[2]), int(dlist[1]),
int(dlist[0]), int(tlist[0]),
int(tlist[1]), int(tlist[2]),
-1, -1, 0))
i += 1
The function appears to be working OK as is, but I would welcome any
all suggestions for improving it or making it more idiomatic.
As already said, that ``while`` loop should be a ``for`` loop. But if you
put `m_abbrevs` into a `list` you can replace the loop with a single call
to its `index()` method: ``dlist[1] = m_abbrevs.index(dlist[1]) + 1``.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: psyco question
On Sun, 03 Feb 2008 10:06:04 -0800, miller.paul.w wrote: Say I have a module with a function f in it, and I do psyco.bind (f) Is there any simple/easy/elegant way to retain a reference to the *unoptimized* version of f so I can call them both and compare performance? What about `psyco.unbind()`? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Does anyone else use this little idiom?
On Sun, 03 Feb 2008 15:13:14 +1100, Ben Finney wrote: Gabriel Genellina [EMAIL PROTECTED] writes: Should be `for _ in xrange(n)` to match the Ruby example. Both iterate n times. Only until Python 3.0, since the 'xrange' implementation will become 'range' at that time. The point wasn't `range` vs. `xrange` but the arguments (1,n) vs. (n). Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Does anyone else use this little idiom?
On Sun, 03 Feb 2008 05:33:16 -0800, Ivan Illarionov wrote: Plain Python function are very often more powerful than classes: def go(count): ... if not hasattr(go, 'count'): ... go.count = count ... if go.count = 0: ... del go.count ... return False ... go.count -= 1 ... return True ... while go(3): ... print 'hello' ... hello hello hello Please try: while go(3): while go(3): print 'Think about it...' Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Unicode literals to latin-1
On Wed, 30 Jan 2008 09:57:55 +0100, David.Reksten wrote:
How can I convert a string read from a database containing unicode
literals, such as Fr\u00f8ya to the latin-1 equivalent, Frøya?
I have tried variations around
Fr\u00f8ya.decode('latin-1')
but to no avail.
In [388]: 'Fr\u00f8ya'.decode('unicode-escape')
Out[388]: u'Fr\xf8ya'
In [389]: print 'Fr\u00f8ya'.decode('unicode-escape')
Frøya
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Removing Pubic Hair Methods
On Tue, 29 Jan 2008 11:48:38 -0800, Tobiah wrote: class genital: def pubic_hair(self): pass def remove(self): del(self.pubic_hair) I think `pubic_hair` is an attribute instead of a method. Oh, and ``del`` is a statement and not a function. So the way you wrote it with parentheses is a bit misleading. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Removing Pubic Hair Methods
On Wed, 30 Jan 2008 15:29:45 +0100, Wildemar Wildenburger wrote: Gerardo Herzig wrote: I will use genital().extend(), thats for shure ^^ Well, you never go wrong with apply(genital(), females), do you? `apply()` is deprecated. And ``genital(*females)`` looks a bit odd. :-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Dictionary Keys question
On Wed, 30 Jan 2008 17:19:13 -0800, Ryszard Szopa wrote: BTW, can anybody explain me how is the hash function implemented in Python? It calls the `__hash__()` method on the object that was given as argument. So there's not *the* hash function, but every type implements its own. Fallback is the hash of the identity of an object: In [415]: class A(object): pass .: In [416]: a = A() In [417]: hash(a) Out[417]: 161029068 In [418]: hash(id(a)) Out[418]: 161029068 Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: read and readline hanging
On Sun, 27 Jan 2008 19:58:27 +0100, Olivier Lefevre wrote: But how can I find out *programmatically* that there is no more input? You can't. How do people handle this, then? Reading from a process that will block if you ask too much yet won't let you know how much there is to read right now has to be some kind of FAQ. It's impossible to handle if the external process does not tell you somehow if there's still data ahead or if it is finished. Then there's only the closing of the file on the process' side that tells you the definitive end of the data. This doesn't answer if the interpreter doesn't flush its output buffer after every line. I think it must otherwise you might get incomplete answers or no answers at the interactive prompt and that never happens. It may not flush its buffer after every line but it must flush them at the end of an answer. The buffering behavior at the interactive prompt is very often different from connections via pipes. If stdout of a process is connected to a terminal the standard C library chooses line buffering but if it is connected to a pipe or redirected to a file it chooses block buffering instead. In such cases the `pexpect` module might be a solution. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: optional static typing for Python
On Mon, 28 Jan 2008 08:31:43 -0800, John Nagle wrote: Unenforced static typing is somewhat pointless. If that goes in, it should be enforced by implementations. Luckily we don't get static typing. We get annotations which *can* be used for type hints, checked by additional code. Can be used for other things as well. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: A question about osyco
On Mon, 28 Jan 2008 05:31:41 -0800, iu2 wrote: I wrote two version of a fib functions, a recursive one and an iterative one. Psyco improved a lot the recursive function time, but didn't affect at all the iterative function. Why? Try calling the iterative one twice and measure the time of the second call. IIRC psyco needs at least one call to analyze the function, so the first call is not speed up. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: how to make format operator % work with unicode as expected
On Sun, 27 Jan 2008 05:32:40 +, Peter Pei wrote: You didn't understand my question, but thanks any way. Yes, it is true that %s already support unicode, and I did not contradict that. But it counts the number of bytes instead of characters, and makes things like %-20s out of alignment. If you don't understand my assertion, please don't argue back and I am only interested in answers from those who are qualified. I have the impression from your original post […] because it is unicode, and one byte is not neccessary one character. that you confuse unicode and utf-8. Are you sure you are qualified to ask such a question in the first place!? :-þ Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Sorting Large File (Code/Performance)
On Sun, 27 Jan 2008 10:00:45 +, Grant Edwards wrote: On 2008-01-27, Stefan Behnel [EMAIL PROTECTED] wrote: Gabriel Genellina wrote: use the Windows sort command. It has been there since MS-DOS ages, there is no need to download and install other packages, and the documentation at http://technet.microsoft.com/en-us/library/bb491004.aspx says: Limits on file size: The sort command has no limit on file size. Sure, since no-one can ever try it with more than 640k, it's easy to state that there is no limit. :) Huh? I used DOS sort to sort files much bigger than 640K. That was an allusion to a quote misattributed to Bill Gates about DOS: 640K ought to be enough for anybody. http://en.wikiquote.org/wiki/Bill_Gates#Misattributed Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Some questions about decode/encode
On Sun, 27 Jan 2008 02:18:48 -0800, glacier wrote: Yepp. I feed SAX with the unicode string since SAX didn't support my encoding system(GBK). If the `decode()` method supports it, IMHO SAX should too. Is there any way to solve this better? I mean if I shouldn't convert the GBK string to unicode string, what should I do to make SAX work? Decode it and then encode it to utf-8 before feeding it to the parser. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: translating Python to Assembler
On Sun, 27 Jan 2008 10:55:20 +, over wrote: On Sat, 26 Jan 2008 14:47:50 +0100, Bjoern Schliessmann [EMAIL PROTECTED] wrote: The script is essentially gone. I'd like to know how to read the pyc files, but that's getting away from my point that there is a link between python scripts and assembler. At this point, I admit the code above is NOT assembler, but sooner or later it will be converted to machine code by the interpreter and the OS and that can be disassembled as assembler. No it will not be converted to assembler. The byte code is *interpreted* by Python, not compiled to assembler. If you want to know how this happens get the C source code of the interpreter and don't waste your time with disassembling `python.exe`. C is much easier to read and there are useful comments too. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: translating Python to Assembler
On Sun, 27 Jan 2008 11:23:20 +, over wrote: Don't fucking tell me about assembler, you asshole. I can read disassembled code in my sleep. Yes you can read it, but obviously you don't understand it. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: translating Python to Assembler
On Sun, 27 Jan 2008 13:41:54 +, Steven D'Aprano wrote: On Sun, 27 Jan 2008 10:55:20 +, over wrote: I can understand people thinking I'm full of beans. Oh no, not full of beans. Full of something, but not beans. Everything you have written about assembly, machine code, compilers, Linux, Python and so forth has been a confused mish-mash of half-truths, distortions, vaguely correct factoids and complete nonsense. I'm starting to wonder if it is possible for somebody to be simultaneously so self-assured and so ignorant, or if we're being trolled. I recently learned that this is called the Dunning-Kruger effect: The Dunning-Kruger effect is the phenomenon wherein people who have little knowledge think that they know more than others who have much more knowledge. […] The phenomenon was demonstrated in a series of experiments performed by Justin Kruger and David Dunning, then both of Cornell University. Their results were published in the Journal of Personality and Social Psychology in December 1999. http://en.wikipedia.org/wiki/Dunning-Kruger_effect See, there's almost always a rational explanation. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: how to make format operator % work with unicode as expected
On Sun, 27 Jan 2008 16:00:42 +, Peter Pei wrote:
Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
On Sun, 27 Jan 2008 05:32:40 +, Peter Pei wrote:
You didn't understand my question, but thanks any way.
Yes, it is true that %s already support unicode, and I did not contradict
that. But it counts the number of bytes instead of characters, and makes
things like %-20s out of alignment. If you don't understand my assertion,
please don't argue back and I am only interested in answers from those
who are qualified.
I have the impression from your original post
[…] because it is unicode, and one byte is not neccessary one character.
that you confuse unicode and utf-8. Are you sure you are qualified to
ask such a question in the first place!? :-þ
so you are saying, with utf-8 encoding a byte is a character, shame on
you.
No I don't say that. I say unicode has no bytes but codepoints. And with
unicode objects Python counts characters and not bytes. So I guess you
are trying to format utf-8 encoded byte strings instead of unicode
strings. Because with unicode strings your problem simply does not
exist. As several people already *showed* to you with examples. Once
again:
In [346]: u = u'sm\xf8rebr\xf8d'
In [347]: s = u.encode('utf-8')
In [348]: print '%-20s+\n%-20s+' % (s, 'spam')
smørebrød +
spam+
In [349]: print '%-20s+\n%-20s+' % (u, 'spam')
smørebrød +
spam+
348 is what you are doing, utf-8 encoded byte strings, but you claim that's
a problem with unicode.
And 349 is formatting unicode. See, no problem -- lines up nicely.
Instead of embarrassing yourself and being rude to people you should take
some time and learn something about unicode and encodings. Especially that
utf-8 ≠ unicode.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: translating Python to Assembler
On Sat, 26 Jan 2008 03:09:05 +, Steven D'Aprano wrote: On Wed, 23 Jan 2008 08:49:20 +0100, Christian Heimes wrote: It's even possible to write code with Python assembly and compile the Python assembly into byte code. Really? How do you do that? I thought it might be compile(), but apparently not. Maybe `bytecodehacks`_ + `psyco`, or PyPy!? .. _bytecodehacks: http://sourceforge.net/projects/bytecodehacks/ Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: When is min(a, b) != min(b, a)?
On Fri, 25 Jan 2008 07:57:38 +, Pete Forman wrote: Mark Dickinson [EMAIL PROTECTED] writes: Any change to Python that made == and != checks involving NaNs raise an exception would have to consider the consequences for set, dict, list membership testing. […] and if Python had separate operators for these two purposes it wouldn't be Python any more. There are separate Python operators, == and is. So what? ``==`` is used for both ``==`` and set/dict/list membership testing and nested comparison of those structures. There is no ``is`` involved. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: read and readline hanging
On Fri, 25 Jan 2008 17:31:16 +0100, Olivier Lefevre wrote:
Thanks for the answer. Yes this is tricky. I have done it in Java
before, where you can, e.g., set up a thread to pump stuff out of
both stderr and stdout continuously but my python is too rudimentary
for that.
The `trheading` module is modeled after Java's threading API.
There is a key difference anyway: in Java you can write
while (br.readLine() != null) { pump }
where br is the buffered reader in which you've wrapped the stdout
of the child process and it will not hang. But in python eventually
stdout.readline() hangs. This is a real nuisance: why can't it just
return None?
Because that would be quite annoying because most of the time people want
blocking behavior.
1. The subprocess has stopped producing output.
Indeed, if I do this interactively, I can tell after 3 lines that I've
gotten all there is to get right now and the fourth readline() call
hangs. But how can I find out *programmatically* that there is no more
input?
You can't.
If you are only reading its standard output, are you sure that the
subprocess is flushing its buffers so you can recognize it's time to
provide more input?
The subprocess in a purely passive position: it is an interpreter: I
send it commands and I read the answers. The python side is in charge.
This doesn't answer if the interpreter doesn't flush its output buffer
after every line.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: is possible to get order of keyword parameters ?
On Fri, 25 Jan 2008 05:49:40 -0800, rndblnch wrote: def f(**kwargs): skipped return result such as : f(x=12, y=24) == ['x', 'y'] f(y=24, x=12) == ['y', 'x'] what i need is to get the order of the keyword parameters inside the function. any hints ? Impossible. Dictionaries are unordered. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Some questions about decode/encode
On Wed, 23 Jan 2008 19:49:01 -0800, glacier wrote: My second question is: is there any one who has tested very long mbcs decode? I tried to decode a long(20+MB) xml yesterday, which turns out to be very strange and cause SAX fail to parse the decoded string. That's because SAX wants bytes, not a decoded string. Don't decode it yourself. However, I use another text editor to convert the file to utf-8 and SAX will parse the content successfully. Because now you feed SAX with bytes instead of a unicode string. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: piping into a python script
On Thu, 24 Jan 2008 17:17:25 +0200, Donn Ingle wrote: Given these two examples: 1. ./fui.py *.py 2. ls *.py | ./fui.py How can I capture a list of the arguments? I need to get all the strings (file or dir names) passed via the normal command line and any that may come from a pipe. There is a third case: 3. ls *.jpg | ./fui.py *.png Where I would be gathering strings from two places. I am trying to write a command-line friendly tool that can be used in traditional gnu/linux ways, otherwise I'd skip the pipe stuff totally. I have tried: 1. pipedIn = sys.stdin.readlines() Works fine for example 2, but example 1 goes into a 'wait for input' mode and that's no good. Is there a way to tell when no input is coming from a pipe at all? Usually Linux tools that can get the data from command line or files treat a single - as file name special with the meaning of: read from stdin. So the interface if `fui.py` would be: 1. ./fui.py *.a 2. ls *.a | ./fui.py - 3. ls *.a | ./fui.py *.b - Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Module/package hierarchy and its separation from file structure
On Wed, 23 Jan 2008 03:49:56 -0600, Peter Schuller wrote: Let me just shoot down one possible suggestion right away, to show you what I am trying to accomplish: I do *not* want to simply break out X into org.lib.animal.x, and have org.lib.animal import org.lib.animal.x.X as X. Then you shoot down the idiomatic answer I guess. That's what most people do. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Stripping whitespace
On Wed, 23 Jan 2008 10:50:02 -0800, ryan k wrote: Hello. I have a string like 'LNAME PASTA ZONE'. I want to create a list of those words and basically replace all the whitespace between them with one space so i could just do lala.split(). Thank you! You *can* just do ``lala.split()``: In [97]: lala = 'LNAME PASTA ZONE' In [98]: lala.split() Out[98]: ['LNAME', 'PASTA', 'ZONE'] Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: what's this instance?
On Tue, 22 Jan 2008 15:36:49 +0800, J. Peng wrote: def safe_float(object): try: retval = float(object) except (ValueError, TypeError), oops: retval = str(oops) return retval x=safe_float([1,2,3,4]) print x The code above works well.But what's the instance of oops? where is it coming from? I'm totally confused on it.thanks. `oops` is bound to the `ValueError` or `TypError` object if `float()` raises such an exception. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on sort() key function
On Tue, 22 Jan 2008 09:56:55 +, Robert Latest wrote: Peter Otten wrote: Robert Latest wrote: This should work then: def date_key(f): return f.mod_date.toordinal() flist.sort(key=date_key) This can also be written as flist.sort(key=lambda f: f.mod_date.toordinal()) Well, that's almost Paul's (non-working) suggestion above, but it works because of the parentheses after toordinal. Beats me how both versions can be valid, anyway. To me it's all greek. I grew up with C function pointers, and they always work. robert Suppose `func` is a C function pointer, then foo = func; and foo = func(); have different meanings. It's just the same in Python. First is the function itself, second *calls* the function. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: problem with 'global'
On Mon, 21 Jan 2008 17:08:46 -0200, Gabriel Genellina wrote: The future statement is another example, even worse: if 0: from __future__ import with_statement with open(xxx) as f: print f In Python =2.5 it's a compile time error if that import is not the very first statement in a source file. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: XOR encryption
On Fri, 18 Jan 2008 03:06:51 -0800, joe jacob wrote:
I wrote a python script to perform XOR encryption on a text and write
the encrypted text to a file. But when I try to read the file as the
encrypted text contains an EOF in between the file is read only to the
first EOF and remaining part of the text is not read.
You have to open the file in binary mode ('rb'/'wb') instead of text mode
('r'/'w') to stop Windows from interpreting the EOF character this way.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: super, decorators and gettattribute
On Sat, 12 Jan 2008 14:23:52 -0800, Richard Szopa wrote: However, I am very surprised to learn that super_object.__getattr__(name)(*args, **kwargs) getattr(super_object, name)(*args, **kwargs) are not equivalent. This is quite odd, at least when with len() and .__len__, str() and .__str__. Do you maybe know what's the rationale behind not following that convention by getattr? I think you are confusing `__getattr__` and `__getattribute__` here! `getattr()` maps to `__getattr__()`, it's `__getattribute__` that's different. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: encrypting python modules
On Sat, 12 Jan 2008 09:47:26 +1100, Ben Finney wrote: Trying to make bits uncopyable and unmodifiable is like trying to make water not wet. Certainly not. I can put water into the freezer, but I have no idea how to make bits uncopyable and unmodifiable while still delivering them to the clients for execution. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedding python code into text document question.
On Thu, 10 Jan 2008 14:10:05 +0100, Thomas Troeger wrote: I've written a program that parses a string or file for embedded python commands, executes them and fills in the returned value. The input might look like this: process id: $$return os.getpid()$$ current date: $$return time.ctime()$$ superuser: $$ if os.geteuid(): return Yes else: return No$$ I've tried several solutions using eval, execfile or compile, but none of those would solve my problem. Does anyone have a solution that works? Any suggestions? Any help will be appreciated :) My suggestion would be: use one of the many already existing templating systems. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: adding methods at runtime
On Thu, 10 Jan 2008 14:55:18 -0800, [EMAIL PROTECTED] wrote: Can I access the class attributes from a method added at runtime? (My experience says no.) I experimented with the following code: [Code snipped] So it seems to me, if you add a method to an instance, the method will not get self as parameter. You are not adding a method but a function. Take a look at `types.MethodType()` to create a method from a function, instance, and class. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: problem of converting a list to dict
On Wed, 09 Jan 2008 10:56:36 -0800, Louis.Soninhu wrote:
Hi pals
I have a list like this
mylist=['','tom=boss','mike=manager','paul=employee','meaningless']
I'd like to remove the first and the last item as they are irrevalent,
and convert it to the dict:
{'tom':'boss','mike':'manager','paul':'employee'}
I tried this but it didn't work:
mydict={}
for i in mylist[1:-1]:
a=i.split('=') # this will disect each item of mylist into a
2-item
list
mydict[a[0]]=a[1]
and I got this:
File srch, line 19, in module
grab(a/tags1)
File srch, line 15, in grab
mydict[mylist[0]]=mylist[1]
IndexError: list index out of range
Anyone could shed me a light on this?
The real list you used had at least one string without a '=' in it. The
list given above doesn't raise that exception:
In [102]: mylist=['','tom=boss','mike=manager','paul=employee','meaningless']
In [103]: mydict={}
In [104]: for i in mylist[1:-1]:
.: a=i.split('=')
.: mydict[a[0]]=a[1]
.:
In [105]: mydict
Out[105]: {'mike': 'manager', 'paul': 'employee', 'tom': 'boss'}
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Pet Store
On Mon, 07 Jan 2008 22:21:53 -0800, George Maggessy wrote: I'm an experience Java developer trying to learn Python. I just finished the Python tutorial on python.org and I'm currently reading the Learning Python book. However, if I could find something like a simple web app with some best practices, such as those famous Java Pet Store apps, I think that would help me to fill up some gaps in my learning process. Does anybody know any app like that? Isn't that a web application using Java web frameworks? So you are looking for a Python web framework with a Pet Store tutorial? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: popen question
On Tue, 08 Jan 2008 09:20:16 +, Robert Latest wrote: The program slow just writes the numbers 0 through 9 on stdout, one line a second, and then quits. I would have expected the python program to spit out a numbers one by one, instead I see nothing for 10 seconds and then the whole output all at once. How can I get and process the pipe's output at the pace it is generated? Both processes have to make their communication ends unbuffered or line buffered. See the documentation of `os.popen()` for the `bufsize` argument. And do whatever is needed to output the numbers from ``slow`` unbuffered or line buffered. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: python syntax:urgent
On Tue, 08 Jan 2008 10:03:56 +0100, Jeroen Ruigrok van der Werven wrote: -On [20080108 09:42], mpho raborife ([EMAIL PROTECTED]) wrote: subprocess.Popen([gmmscore, -i, Input, -l, List, -t, modeltype, -m, str(mixture), -d, str(dimension), -v, str(vfloor), -n, str(number), -r, str(results)]) gmmscore, -i seems a bit silly, why not just gmmscore -i? That's definitely *not* silly but the way to go. There are two ways: The above that calls the executable with the arguments as given, or with a string like you suggests which is interpreted by a shell, so the arguments must be escaped for that shell. Which shell? Depends on the system! You can always do something like (assuming all arguments are strings, adjust accordingly): s = gmmscore -i %s -l %s -t %s -m %s -d %s -v %s -n %s -r %s % (Input, List, modeltype, str(mixture), str(dimension), str(vfloor), str(number), str(results)) subprocess.Popen([s]) Here you are trying to start a program named gmmscore -i ... with no arguments. That fails (unless you really have a program with that name. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Point Object
On Sat, 05 Jan 2008 03:37:33 -0800, [EMAIL PROTECTED] wrote: I am nes to python and need some help. Can anyone lead me in the right direction to create and print a Point object, and then use id to print the object's unique identifier. Translate the hexadecimal form into decimal and confirm that they match. The right direction would be the tutorial in the docs I guess: http://docs.python.org/tut/tut.html What do you mean by the hexadecimal form? `id()` returns ordinary `int`\s and not strings. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: wxpython application ( problem ? )
On Wed, 02 Jan 2008 03:24:56 -0800, vedrandekovic wrote: Here is sample of my simple script with wxpython and modules: subprocess,threading, directpython... Are you accessing the GUI from threads? Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: pdf library.
On Tue, 01 Jan 2008 04:21:29 -0800, Shriphani wrote: On Jan 1, 4:28 pm, Piet van Oostrum [EMAIL PROTECTED] wrote: Shriphani[EMAIL PROTECTED] (S) wrote: S I tried pyPdf for this and decided to get the pagelinks. The trouble S is that I don't know how to determine whether a particular page is the S first page of a chapter. Can someone tell me how to do this ? AFAIK PDF doesn't have the concept of Chapter. If the document has an outline, you could try to use the first level of that hierarchy as the chapter starting points. But you don't have a guarantee that they really are chapters. How would a pdf to html conversion work ? I've seen Google's search engine do it loads of times. Just that running a 500odd page ebook through one of those scripts might not be such a good idea. Heuristics? Neither PDF nor HTML know chapters. So it might be guesswork or just in your head. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: at what complexity, a comparison fails ?
On Mon, 31 Dec 2007 11:45:55 +0100, Stef Mientki wrote: Now one of the interface mechanisms was to see if some parameter was changed in a an instance, by comparing the value from the instance with its previous value This went all well, untill I added a too complex variable, then the program stopped working, without generating exceptions. So it seems that comparing a too complex value isn't allowed. Then you get the wrong impression. the variable was something like: A = [ ndarray, ndarray, ..., [color,color,...], [float, float, ... ] ] So what I need was something like: if A != A_prev : ... do something A_prev = A And this crashes, or at least it doesn't work but also doesn't generate exceptions. It does seems to work, if A only contains 1 array. Why am I not allowed to compare A and A_prev ?? You are allowed and you do in the above code. And in general, how complex might a list be to make a valid comparison, or what are the rules ? There are no rules about the complexity. Lists are compared element wise. If the lists are of the same length and all elements at the corresponding indexes compare equal, the lists are considered equal. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Fate of itertools.dropwhile() and itertools.takewhile()
On Sat, 29 Dec 2007 15:10:24 -0800, Raymond Hettinger wrote: These thoughts reflect my own experience with the itertools module. It may be that your experience with them has been different. Please let me know what you think. I seem to be in a minority here as I use both functions from time to time. One recipe is extracting blocks from text files that are delimited by a special start and end line. def iter_block(lines, start_marker, end_marker): return takewhile(lambda x: not x.startswith(end_marker), dropwhile(lambda x: not x.startswith(start_marker), lines)) Maybe these functions usually don't turn up in code that can be called recipes so often but are useful for themselves. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: OOP: How to implement listing al 'Employees'.
On Sat, 29 Dec 2007 01:53:38 -0800, Petar wrote: The post of Dennis made me realize of another solution though. To create another class called Articles which return multiple articles. The only problem I forsee with this that's it's gonna be a very empty class. Then maybe it should not be a class. Maybe a function returning `Article`\s would be enough. This is not Java, not everything has to be stuffed into classes. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Optional code segment delimiter?
On Sat, 29 Dec 2007 09:20:00 -0800, xkenneth wrote: Is it possible to use optional delimiters other than tab and colons? No. And is there an alternate delimiter for statements other than the newline? print this;print that; #for example Yes. But both are reasons to yell at you. ;-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Happy Christmas Pythoneers
On Thu, 27 Dec 2007 22:38:44 -0800, Aahz wrote: In article [EMAIL PROTECTED], Steven D'Aprano [EMAIL PROTECTED] wrote: On Wed, 26 Dec 2007 21:32:54 -0800, [EMAIL PROTECTED] wrote: Hey, my version of the person module doesn't have an is_appropriate_sex attribute, but an is_opposite_sex attribute instead. Is this a new version? Generally instances use: person.is_appropriate_sex = person.is_opposite_sex but some instances define it as: person.is_appropriate_sex = not person.is_opposite_sex It's an implementation detail, you shouldn't worry about it. Then again, some instances define it as person.is_appropriate_sex = True And sometimes it's not that simple but a property and connected with the caller's history of `champagne.drink()` calls. The `person.is_pretty` property is most definitely linked to that call history in many instances. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: unicode(s, enc).encode(enc) == s ?
On Fri, 28 Dec 2007 03:00:59 -0800, mario wrote: On Dec 27, 7:37 pm, Martin v. Löwis [EMAIL PROTECTED] wrote: Certainly. ISO-2022 is famous for having ambiguous encodings. Try these: unicode(Hallo,iso-2022-jp) unicode(\x1b(BHallo,iso-2022-jp) unicode(\x1b(JHallo,iso-2022-jp) unicode(\x1b(BHal\x1b(Jlo,iso-2022-jp) or likewise unicode([EMAIL PROTECTED],iso-2022-jp) unicode(\x1b$BBB,iso-2022-jp) In iso-2022-jp-3, there are even more ways to encode the same string. Wow, that's not easy to see why would anyone ever want that? Is there any logic behind this? In your samples both of unicode(\x1b(BHallo,iso-2022-jp) and unicode(\x1b(JHallo,iso-2022-jp) give uHallo -- does this mean that the ignored/lost bytes in the original strings are not illegal but *represent nothing* in this encoding? They are not lost or ignored but escape sequences that tell how the following bytes should be interpreted '\x1b(B' switches to ASCII and '\x1b(J' to some roman encoding which is a superset of ASCII, so it doesn't matter which one you choose unless the following bytes are all ASCII. And of course you can use that escape prefix as often as you want within a string of ASCII byte values. http://en.wikipedia.org/wiki/ISO-2022-JP#ISO_2022_Character_Sets I.e. in practice (in a context limited to the encoding in question) should this be considered as a data loss, or should these strings be considered equivalent? Equivalent I would say. As Unicode they contain the same characters. Just differently encoded as bytes. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange Behavior: csv module IDLE
On Fri, 28 Dec 2007 18:12:58 -0800, t_rectenwald wrote:
Within the program, the snippet where I use the csv module is below:
==
csvfile = open('foo.csv', 'w')
writer = csv.writer(csvfile)
for row in rows:
writer.writerow(row[0:3])
csvfile.close
==
The rows object is returned from a database query and is a list of
tuples. Now here is the strange thing. If I run this program
directly from the command line, i.e.,
D:\test D:\python25\python foo.py
It runs fine, foo.csv is created and all is well. However, when I run
it through the IDLE shell as described above, the foo.csv file is
created but remains empty at 0 bytes. When I try to delete the file,
Windows says it is in use. The only way I can break out of this is by
restarting the IDLE shell. In other words, it appears that the shell
is hanging.
This will run through Task Scheduler, so shouldn't be a problem, but
I'm worried that I'm coding this wrong for it to be acting this way
under IDLE. Any help or explanation would be appreciated.
You are not closing the file so the buffered data is not written to disk.
To call a function you need the parenthesis, otherwise you are just
referencing it without any effect.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Passing by reference
On Sun, 23 Dec 2007 03:10:48 -0800, MartinRinehart wrote: Bruno, right now I've got this: def __init__ ( self, t ): Constructor, called with array of strings. self.text = t ... Some other program will say: tok = Toker( text_array ) tokens = tok.tokenize() So how does the constructor make the array of strings available to the tokenize() method? Assuming the `__init__()` above belongs to the `Toker` class then the `tokenize()` method can access it via `self.text` of course. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: checking for negative values in a list
On Mon, 17 Dec 2007 06:20:23 -0800, vimal wrote: i have a list of numbers say a = [1,-1,3,-2,4,-6] how should i check for negative values in the list In [6]: a = [1, -1, 3, -2, 4, -6] In [7]: any(n 0 for n in a) Out[7]: True Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
