Re: Balanced trees

On Tue, Mar 11, 2014 at 1:20 PM, Roy Smith wrote: > In article <531e6eca$0$29994$c3e8da3$54964...@news.astraweb.com>, > Steven D'Aprano wrote: > >> There's only so much matter in the >> universe, so talking about limits as the amount of data approaches >> infinity is nonsense. Where would you st

querry on queue ( thread safe ) multithreading

hey i am working on scraping a site , so i am using multi-threading concept. i wrote a code based on queue (thread safe) but still my code block out after sometime, please help , i have searched a lot but unable to resolve it. please help i stuck here. my code is under .. +

Re: Struggling to create an extension wrapping a 3rd party dll

On Wednesday, 5 March 2014 09:10:33 UTC+2, Christoff Kok wrote: > Hi, > > > > We are trying to wrap a 3rd party dll (written in C) to access it through > python. > > The dll has a .lib .c and a .h file with it. We are accessing the dll through > the .c file. > > > > Outisde of the extensi

Re: Tuples and immutability

Ian Kelly wrote: If the in-place behavior of += is held to be part of the interface, then we must accept that += is not polymorphic across mutable and immutable types, That's quite correct, it's not. As I said, it's one notation doing double duty. Usually there isn't any confusion, because you

Re: Tuples and immutability

Ian Kelly wrote: It's technically "possible" for this augmented assignment to be performed in place: x = 12 x += 4 But it's not done in-place, because ints are meant to be immutable. Which means it's *not* possible, because doing so would violate the documented properties of the int type. I

Re: Balanced trees

On Tue, Mar 11, 2014 at 2:38 PM, Ian Kelly wrote: > On Mon, Mar 10, 2014 at 7:45 PM, Chris Angelico wrote: >> No no, >> I could make this so much better by using the 80x86 "REP MOVSW" >> command (or commands, depending on your point of view). That would be >> so much better than all those separat

Re: Balanced trees

On Mon, Mar 10, 2014 at 7:45 PM, Chris Angelico wrote: > On Tue, Mar 11, 2014 at 12:26 PM, Steven D'Aprano > wrote: >> In my experience, the average developer has an amazing talent for >> pessimising code when they think they are optimising it. > > I remember a number of incidents from personal e

Re: gdb unable to read python frame information

Now, I fixed the problem... Instead of python2.6.6, for python 2.7 it's OK.. Why? gdb does not support python 2.6.6? Is it related to python-gdb.py? I googled a lot, seems only has python2.7-gdb.py, no python2.6-gdb.py. 在 2014年3月10日星期一UTC+8下午3时28分30秒，dieter写道： > Wesley writes: > > > > > I

Re: Balanced trees

In article <531e6eca$0$29994$c3e8da3$54964...@news.astraweb.com>, Steven D'Aprano wrote: > There's only so much matter in the > universe, so talking about limits as the amount of data approaches > infinity is nonsense. Where would you store it? Funny you should ask that. I just finished watc

Re: Balanced trees

In article , Dan Stromberg wrote: > On Mon, Mar 10, 2014 at 6:59 AM, Roy Smith wrote: > > On the other hand, log n, for n = 1 million, is just 20. It's not hard > > to imagine a hash function which costs 20x what a node traversal does, > > in which case, the log n lookup is ahead for all n < 1

Re: Balanced trees

On Mon, 10 Mar 2014 09:01:23 -0700, Rustom Mody wrote: > 2. Being pointed out that a finite-input table-lookup being called a > hash-function is a rather nonsensical claim and goes counter to the > basic tenets of asymptotic notation. (In CS unlike in math 'asymptote' > is always infinity) IOW Th

Re: Balanced trees

On Tue, Mar 11, 2014 at 12:26 PM, Steven D'Aprano wrote: > In my experience, the average developer has an amazing talent for > pessimising code when they think they are optimising it. I remember a number of incidents from personal experience when I was a *very* average developer. One time, writin

Re: gdb unable to read python frame information

[root@localhost ~]# gdb python GNU gdb (GDB) Red Hat Enterprise Linux (7.2-60.el6_4.1) Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRA

Re: Balanced trees

On Mon, 10 Mar 2014 19:24:07 -0400, Roy Smith wrote: > In article <8761nmrnfk@elektro.pacujo.net>, > Marko Rauhamaa wrote: > >> Anyway, this whole debate is rather unnecessary since every developer >> is supposed to have both weapons in their arsenal. > > The problem with having a choice i

Re: Balanced trees

On Mon, Mar 10, 2014 at 6:59 AM, Roy Smith wrote: > On the other hand, log n, for n = 1 million, is just 20. It's not hard > to imagine a hash function which costs 20x what a node traversal does, > in which case, the log n lookup is ahead for all n < 1 million. FWIW, both the hash table and the

Re: when to use == and when to use is

I agree with Ben. In this particular case, it seems you really should be using "==" unless obj_0, obj_1, and obj_2 are sentinels. Skip -- https://mail.python.org/mailman/listinfo/python-list

Re: Closure/method definition question for Python 2.7

On Mon, Mar 10, 2014 at 11:27 AM, Brunick, Gerard:(Constellation) wrote: > The following code: > > --- > class Test(object): > x = 10 > > def __init__(self): > self.y = x > > t = Test() > --- > > raises > > NameError: global name 'x' is not defined. > > in Python 2.7. I don't unde

Re: Testing interactive code using raw_input

Steven D'Aprano writes: > Does anyone have any good hints for testing interactive code that uses > raw_input, or input in Python 3? Are you testing the behaviour of the ‘input’ function? If not, then it is an external dependency; and, since you're not interested in testing its behaviour, you c

Re: Loading a module from a subdirectory

Virgil Stokes wrote: > I have the following folder-file structure: > > C:/PythonCode/VideoPlayerSimulator/ > +-- __init__.py (empty file) > +-- GlbVars.py (contains the single > class Glb) > > C:/PythonCode/VideoPlayerSi

Re: Balanced trees

On Tue, Mar 11, 2014 at 10:24 AM, Roy Smith wrote: > As this discussion has shown, figuring out whether a hash table or a > tree is better for a given problem is non-trivial. My guess is that if > you gave 1000 typical developers both data structures and let them pick > freely, the number of case

Re: Balanced trees

In article <8761nmrnfk@elektro.pacujo.net>, Marko Rauhamaa wrote: > Anyway, this whole debate is rather unnecessary since every developer is > supposed to have both weapons in their arsenal. The problem with having a choice is that it opens up the possibility of making the wrong one :-) A

Re: which async framework?

On 3/10/2014 4:38 PM, Chris Withers wrote: Hi All, I see python now has a plethora of async frameworks and I need to try and pick one to use from: - asyncio/tulip - tornado - twisted From my side, I'm looking to experimentally build a network testing tool that will need to speak a fair few ne

Re: when to use == and when to use is

George Trojan writes: > Both if statements work, of course. Which is more efficient? I don't know. The answer is likely to be dependent on many details of the code and the data. But I do know that the different operators communicate different intents. And that should be a primary reason for ch

Re: when to use == and when to use is

On 3/10/14 2:09 PM, George Trojan wrote: I know this question has been answered: http://stackoverflow.com/questions/6570371/when-to-use-and-when-to-use-is , but I still have doubts. Consider the following code: class A: def __init__(self, a): self._a = a #def __eq__(self, othe

Loading a module from a subdirectory

I have the following folder-file structure: C:/PythonCode/VideoPlayerSimulator/ +-- __init__.py (empty file) +-- GlbVars.py (contains the single class Glb) C:/PythonCode/VideoPlayerSimulator/RubberBanding/

Re: Loading a module from a subdirectory

On 10-Mar-14 21:31, Virgil Stokes wrote: I have the following folder-file structure: C:/PythonCode/VideoPlayerSimulator/ +-- __init__.py (empty file) +-- GlbVars.py (contains the single class Glb) C:/PythonCode/VideoPlayerS

when to use == and when to use is

I know this question has been answered: http://stackoverflow.com/questions/6570371/when-to-use-and-when-to-use-is , but I still have doubts. Consider the following code: class A: def __init__(self, a): self._a = a #def __eq__(self, other): #return self._a != other._a ob

which async framework?

Hi All, I see python now has a plethora of async frameworks and I need to try and pick one to use from: - asyncio/tulip - tornado - twisted From my side, I'm looking to experimentally build a network testing tool that will need to speak a fair few network protocols, both classic tcp and mul

NEW EVIDENCE PROVES HUMAN DEVONIAN ORIGINS

=== >BREAKING NEWS! === NEW YORK TIMES, THRINAXODON, OHIO = > THRINAXODON RECENTLY FOUND 3 HUMAN FOSSILS FROM DEVONIAN STRATA FROM GREENLAND, THE EVOLUTIONISTS HAVE NO BONES ABOUT. > ONE EVIL EVOLUTIONIST, BOB CASANOVA HAS ADMITTED THAT HUMAN EVOLUTIO

Re: Import order question

On 18/02/2014 23:28, Rotwang wrote: [...] I have music software that's a single 9K-line Python module, which I edit using Notepad++ or gedit. Incidentally, in the time since I wrote the above I've started using Sublime Text 3, following somebody on c.l.p's recommendation (I apologise that I

Re: Closure/method definition question (delete 'for Python 2.7')

On 3/10/2014 1:27 PM, Brunick, Gerard:(Constellation) wrote: class Test(object): x = 10 def __init__(self): self.y = x t = Test() --- raises NameError: global name 'x' is not defined. in Python 2.7. In Python, period. I would assume that when __init__ is being defined

Re: Testing interactive code using raw_input

On 03/10/2014 08:59 AM, Steven D'Aprano wrote: With an automated test, I can provide the arguments, and check the result, but what are my options for *automatically* supplying input to raw_input? pexpect? -- ~Ethan~ -- https://mail.python.org/mailman/listinfo/python-list

Re: Closure/method definition question for Python 2.7

"Brunick, Gerard:(Constellation)" : > class Test(object): > x = 10 > > def __init__(self): > self.y = x > > t = Test() > --- > > raises > > NameError: global name 'x' is not defined. In the snippet, x is neither local to __init__() nor global to the module. It is in the class scop

Re: Balanced trees

Chris Angelico : > Supposed to have? What does that mean, a language isn't ISO-compliant > unless it provides both? It's an ancient, fundamental data structure, right up there with dynamic lists. There's no reason it shouldn't be available in every programming environment. > With a high level la

Closure/method definition question for Python 2.7

The following code: --- class Test(object): x = 10 def __init__(self): self.y = x t = Test() --- raises NameError: global name 'x' is not defined. in Python 2.7. I don't understand why. I would assume that when __init__ is being defined, it is just a regular old function an

Re: Balanced trees

On Tue, Mar 11, 2014 at 4:08 AM, Marko Rauhamaa wrote: > Chris Angelico : > >> The only difference between a tree and a hash here is that the tree >> might be able to short-cut the comparisons. But if there are a whole >> bunch of songs with the same "song" and "user", then the tree has to >> comp

Re: Balanced trees

Chris Angelico : > The only difference between a tree and a hash here is that the tree > might be able to short-cut the comparisons. But if there are a whole > bunch of songs with the same "song" and "user", then the tree has to > compare (song->song? same; user->user? same; add_time->add_time? >

Re: Testing interactive code using raw_input

Steven D'Aprano wrote: > Does anyone have any good hints for testing interactive code that uses > raw_input, or input in Python 3? > > A simple technique would be to factor out the interactive part, e.g. like > this: > > # Before > def spam(): > answer = raw_input(prompt) > return eggs(a

Re: Balanced trees

On Tue, Mar 11, 2014 at 3:33 AM, Tim Chase wrote: > On 2014-03-11 03:24, Chris Angelico wrote: >> Imagine, worst case, all one million records have the same >> song/user/add_time and you need to do twenty comparisons involving >> four fields. That's gotta be worse than one hashing of five fields.

Re:Testing interactive code using raw_input

Steven D'Aprano Wrote in message: > Does anyone have any good hints for testing interactive code that uses > raw_input, or input in Python 3? > > A simple technique would be to factor out the interactive part, e.g. like > this: > > # Before > def spam(): > answer = raw_input(prompt) >

Re: Balanced trees

On 2014-03-11 03:24, Chris Angelico wrote: > Imagine, worst case, all one million records have the same > song/user/add_time and you need to do twenty comparisons involving > four fields. That's gotta be worse than one hashing of five fields. And if you have one million songs that are indistinguis

Re: golang OO removal, benefits. over python?

On Tue, Mar 11, 2014 at 3:16 AM, Marko Rauhamaa wrote: > Chris Angelico : > >> Java's MI simply doesn't exist (that's perfectly pure!), although >> implementing interfaces can do a lot of it; but then you end up >> duplicating piles of code (on the other hand, that's nothing new in >> Java code).

Re: Balanced trees

On Tue, Mar 11, 2014 at 12:59 AM, Roy Smith wrote: > Looking at the Songza source, I see we have one user-defined hash > function: > > def __hash__(self): > return hash((self.song, > self.user, > self.add_time, > self.delet

Re: Balanced trees

On Tue, Mar 11, 2014 at 12:59 AM, Roy Smith wrote: > The hash vs. tree argument can get very complicated. For example, if > your tree is not completely resident in memory, the cost of paging in a > node will swamp everything else, and improving lookup speed will boil > down to reducing the number

Re: golang OO removal, benefits. over python?

Chris Angelico : > Java's MI simply doesn't exist (that's perfectly pure!), although > implementing interfaces can do a lot of it; but then you end up > duplicating piles of code (on the other hand, that's nothing new in > Java code). Java 8 has default methods for interfaces. That covers one pri

Re: golang OO removal, benefits. over python?

Le lundi 10 mars 2014 05:49:20 UTC+1, flebber a écrit : > > > Why would a Python user change to go except for new and interesting? > > Unicode jmf -- https://mail.python.org/mailman/listinfo/python-list

Re: Testing interactive code using raw_input

On 10 March 2014 15:59, Steven D'Aprano wrote: > Does anyone have any good hints for testing interactive code that uses > raw_input, or input in Python 3? > > A simple technique would be to factor out the interactive part, e.g. like > this: > > # Before > def spam(): > answer = raw_input(promp

Re: Balanced trees

On Monday, March 10, 2014 4:27:13 PM UTC+5:30, Ned Batchelder wrote: > You are right that you and Steven have had a hard time communicating. > You are part of "you and Steven", it would be at least polite to > consider that part of the reason for the difficulty has to do with your > style. It c

Testing interactive code using raw_input

Does anyone have any good hints for testing interactive code that uses raw_input, or input in Python 3? A simple technique would be to factor out the interactive part, e.g. like this: # Before def spam(): answer = raw_input(prompt) return eggs(answer) + cheese(answer) + toast(answer) #

Re: golang OO removal, benefits. over python?

On Mon, Mar 10, 2014 at 6:50 PM, Ian Kelly wrote: > The author points out that nested structures can be made optional by > including a pointer to the structure instead of the structure itself. > Again you can do the exact same thing in C++; in OOP this is usually > described as a "has-a" relations

Re: debugging on windows

. Unhandled exception at 0x1e0aebb8 in python.exe: 0xC005: Access violation reading location 0x0048. This is a C level error -- likely some memory corruption. You will need a C level debugger to analyse the problem - and likely, it will not be easy. indeed it was. Seem

Re: Import order question

In article , Rotwang wrote: >On 18/02/2014 23:41, Rick Johnson wrote: >> On Tuesday, February 18, 2014 5:28:21 PM UTC-6, Rotwang wrote: > >[snipped material restored for context] > >>> On 18/02/2014 21:44, Rick Johnson wrote: [...] Are you telling me you're willing to search throu

Salutations Python List!

http://lalimitada.com/templates/beez/bbcnews.php?awvq1600afttah Brian Murphy bam...@gmail.com Don't quit now, we might just as well lock the door and throw away the key. --

Re: Can global variable be passed into Python function?

alb...@spenarnc.xs4all.nl (Albert van der Horst): > I can't see why parsers decoders are any different. The Pentium > assembler in my ciforth's ``forth.lab'' library has not a single if > statement and I reckon it is a superior design. (State is kept in an > ai blackboard fashion in bitmaps.) Fort

[ANN] Oktest.py 0.14.0 released - a new-style testing library

I released Oktest.py 0.14.0. http://pypi.python.org/pypi/Oktest/ http://packages.python.org/Oktest/ Oktest.py is a new-style testing library for Python:: from oktest import ok, NG ok (x) > 0 # same as assertTrue(x > 0) ok (s) == 'foo'# same as assertEqual(s

Re: Can global variable be passed into Python function?

In article <87sir2et1d@elektro.pacujo.net>, Marko Rauhamaa wrote: >Mark Lawrence : > >> http://c2.com/cgi/wiki?SwitchStatementsSmell > >Your brief summary, please, Mark? > >Anyway, the first 1000 lines or so that I managed to read from that page >stated a valid principle, which however doesn'

Re: Balanced trees

In article <87eh2atw6s@elektro.pacujo.net>, Marko Rauhamaa wrote: > Steven D'Aprano : > > > Proof: I create a hash table that accepts unsigned bytes as keys, where > > The O(f(n)) notation has no meaning when n is limited. > > This thing is not just pedantry. The discussion was how a bal

Re: image processing in python and opencv

On Sunday, March 9, 2014 2:09:25 PM UTC-5, Gary Herron wrote: > i have no idea how to retrieve indexed images stored in ordered dictionary, > using its values like : blue,green,red mean along with contrast, energy, > homogeneity and correlation. as i have calculated the euclidean distance and >

Re: Windows installation problem with 3.3.5

On 10/03/2014 12:51, Jurko Gospodnetić wrote: Hi. On 10.3.2014. 4:16, Mark Lawrence wrote: It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of py.exe and pyw.exe from c:\windows. Before I raise an issue on the bug tracker could someone please confirm this, as it wouldn't

Re: Windows installation problem with 3.3.5

Hi. On 10.3.2014. 4:16, Mark Lawrence wrote: It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of py.exe and pyw.exe from c:\windows. Before I raise an issue on the bug tracker could someone please confirm this, as it wouldn't be the first time I've managed to screw somethin

ANN: psutil 2.0.0 released

Hi there folks, I'm pleased to announce the 2.0.0 release of psutil: http://code.google.com/p/psutil/ === About === psutil (python system and process utilities) is a cross-platform library for retrieving information on running processes and system utilization (CPU, memory, disks, network) in Pyth

Re: golang OO removal, benefits. over python?

> Also, is there anything seriously lacking in Python, Java and C? > > > Marko >From their FAQ: Go was born out of frustration with existing languages and environments for systems programming. Programming had become too difficult and the choice of languages was partly to blame. One had to ch

Re: Balanced trees

On 3/10/14 5:41 AM, Marko Rauhamaa wrote: Steven D'Aprano : If I am right, that certainly would explain your apparent inability to understand the difference between "is" and == operators, your insistence that object IDs are addresses, and your declaration that object identity is philosophically

Re: Balanced trees

On 10/03/2014 08:53, Steven D'Aprano wrote: In other words, I suspect you are trolling. s/suspect/know/ , he didn't make captain of my dream team for nothing, you know :) -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawre

Re: Balanced trees

Steven D'Aprano : > If I am right, that certainly would explain your apparent inability to > understand the difference between "is" and == operators, your > insistence that object IDs are addresses, and your declaration that > object identity is philosophically untenable. You and I certainly have

Re: Windows installation problem with 3.3.5

On 10/03/2014 08:40, Tim Golden wrote: On 10/03/2014 03:16, Mark Lawrence wrote: It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of py.exe and pyw.exe from c:\windows. Before I raise an issue on the bug tracker could someone please confirm this, as it wouldn't be the first t

Re: Tuples and immutability

On Mon, 10 Mar 2014 02:35:36 -0600, Ian Kelly wrote: > On Sun, Mar 9, 2014 at 8:37 PM, Steven D'Aprano > wrote: >> On Sun, 09 Mar 2014 17:42:42 -0600, Ian Kelly wrote: >> >>> On Sun, Mar 9, 2014 at 4:03 PM, Gregory Ewing >>> wrote: >> Note that it says "when possible", not "if the implement

Re: Windows installation problem with 3.3.5

Hi. On 10.3.2014. 4:16, Mark Lawrence wrote: > It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of > py.exe and pyw.exe from c:\windows. Before I raise an issue on the > bug tracker could someone please confirm this, as it wouldn't be the > first time I've managed to screw s

Re: Balanced trees

On Mon, 10 Mar 2014 08:16:43 +0200, Marko Rauhamaa wrote: > Steven D'Aprano : > >> Proof: I create a hash table that accepts unsigned bytes as keys, where > > The O(f(n)) notation has no meaning when n is limited. It has obvious meaning: O(1) means that look-ups take constant time, not (for ex

Re: Windows installation problem with 3.3.5

On 10/03/2014 03:16, Mark Lawrence wrote: > It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of > py.exe and pyw.exe from c:\windows. Before I raise an issue on the bug > tracker could someone please confirm this, as it wouldn't be the first > time I've managed to screw somethin

Re: golang OO removal, benefits. over python?

Ian Kelly : > The description of how Go structs work is accurate from what I know of > it, but I think the author goes astray in claiming that this is not > OOP. Call it "no-nonsense OOP." No wonder the color of the box was gray in the example. > On the whole though I think that the language is

Re: Windows installation problem with 3.3.5

On 10/03/2014 03:16, Mark Lawrence wrote: > It looks as if the upgrade from 3.3.4 to 3.3.5 has stolen my copies of > py.exe and pyw.exe from c:\windows. Before I raise an issue on the bug > tracker could someone please confirm this, as it wouldn't be the first > time I've managed to screw somethin

Re: Tuples and immutability

On Sun, Mar 9, 2014 at 8:37 PM, Steven D'Aprano wrote: > On Sun, 09 Mar 2014 17:42:42 -0600, Ian Kelly wrote: > >> On Sun, Mar 9, 2014 at 4:03 PM, Gregory Ewing >> wrote: > >>> Note that it says "when possible", not "if the implementation feels >>> like it". >> >> That's quite vague, and not much

Re: golang OO removal, benefits. over python?

On Sun, Mar 9, 2014 at 10:49 PM, flebber wrote: > I was wondering if a better programmer than I could explain if the removal of > OO features in golang really does offer an great benefit over python. > > An article I was reading ran through a brief overview of golang in respect of > OO features

[RELEASED] Python 3.4.0 release candidate 3

On behalf of the Python development team, I'm pleased to announce the third and final** release candidate of Python 3.4. This is a preview release, and its use is not recommended for production settings. Python 3.4 includes a range of improvements of the 3.x series, including hundreds of small

Re: gdb unable to read python frame information

Wesley writes: > If you don't read the loop from the top, and don't tell me exactly what you > want by just keep saying context, please ingore this post. You are doing things only a few people do: trying to debug a Python process on C level -- and you observe really strange things. It is very d

Re: gdb unable to read python frame information

Mark Lawrence writes: > On 10/03/2014 01:06, Wesley wrote: > ... > Context, you just keep sending messages like the above which on its > own is meaningless. The original poster has send messages lacking important pieces of information -- but on request from the list, he has fixed this initial err

Re: gdb unable to read python frame information

Wesley writes: > So, let me clarify here, in order to try, I get a clean machine. > > Centos 6.5 64bit. > Now , I try this: > 1. install gdb 7.7 from source , with configure option --with-python > > 2. install python 2.6.6 from source, with configure option --with-pydebug > > 3. run a python scri