Re: How is AI implemented
On Jan 3, 6:49 pm, Martin Marcher [EMAIL PROTECTED] wrote: Hi, I know it's not a trivial field but I had some readings about artificial intelligence lately and my personal conclusion is that it's mostly just statistics. Naively explained: continiously gather and store information and apply a default rating 1) answer questions with gathered information according to rating 2) store/calculate rating based upon input (be it an interface or user input) 3) goto 1 (sorry for the goto) really naively :) So I think that in general there hasn't yet been any artificial intelligence programmed (Note: I believe I'm aware of the difference between artificial intelligence and artificial conscusiness where the second would be able to answer things like: How are you today and the first can answer factual knowledge) What you want to do is look up the difference between weak AI and strong AI. Everything we have to this day is weak AI, and there is still a debate between various scientists as to whether strong AI is even possible. Be sure to look at Chinese room argument to see if strong AI is really what you need. (http://en.wikipedia.org/wiki/Chinese_room) Am I thinking right here or is there some (preferrably) web reading available on that or in depth links about the topic? thanks and sorry for OT posting martin --http://noneisyours.marcher.namehttp://feeds.feedburner.com/NoneIsYours -- http://mail.python.org/mailman/listinfo/python-list
Re: list in a tuple
After some tought I must agree that this is a wart more than a bug and that it will probably be best not to mess with it. However, what do you guys think about the print wart in Py3k described at http://filoxus.blogspot.com/2007/12/python-3000-how-mutable-is-immutable.html#links (im not trying to advertise my blog, I just don't feel like typing the whole problem all over again)? On 26 pro, 19:11, Arnaud Delobelle [EMAIL PROTECTED] wrote: On Dec 26, 1:08 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: On Mon, 24 Dec 2007 18:01:53 -0800, Raymond Hettinger wrote: [...] The first succeeds and the second fails. And this is a good idea? Shouldn't the tuple assignment raise the exception BEFORE calling __iadd__ on the item, instead of after? If you look at the bytecode generated, this doesn't seem possible: def f(): ... a = ([1],) ... a[0] += [2] ... import dis dis.dis(f) 2 0 LOAD_CONST 1 (1) 3 BUILD_LIST 1 6 BUILD_TUPLE 1 9 STORE_FAST 0 (a) 3 12 LOAD_FAST 0 (a) 15 LOAD_CONST 2 (0) 18 DUP_TOPX 2 21 BINARY_SUBSCR 22 LOAD_CONST 3 (2) 25 BUILD_LIST 1 28 INPLACE_ADD 29 ROT_THREE 30 STORE_SUBSCR 31 LOAD_CONST 0 (None) 34 RETURN_VALUE BINARY_SUBSCR puts a[0] on the stack, it has no way to know that a[0] will be changed in place. To allow an exception to be thrown before the in-place modification of a[0], there should be a new bytecode instruction, say BINARY_SUBSCR_WITH_A_VIEW_TO_CHANGE_IN_PLACE, which checks that the subscriptable object supports STORE_SUBSCR (;-). [...] I was never a big fan of augmented assignments. I think it goes against the Python grain: it's an implied operation, using punctuation, for the sole (?) benefit of saving a keystroke or three. But I think this behaviour counts as a wart on the language, rather than a bug. Yes. I didn't realise this before you mentioned it, but the culprit here seems to be the augmented assignment which acts differently on mutable and immutable objects: b = a # say a is immutable a += c # equivalent to a = a + c b is a # - False b = a # Now say a is mutable a += c # equivalent to a.__iadd__(c) b is a # - True OTOH augmented assignent are a slight optimisation: a[i] += 1 will look for the value of a and i only once and duplicate them on the stack, whereas a[i] = a[i] + 1 will need to resolve a and i twice (which can be costly if a and i are globals) -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
Re: list in a tuple
On Dec 27, 8:20 pm, Wildemar Wildenburger [EMAIL PROTECTED] wrote: From that post: Ok, I do admit that doing a = ([1], 2) a[0].append(2) also doesn't throw an error, but this only confuses me more. Why? You mutate thelist, but thetupledoes not change. It is still atupleof alistand an int. At least that's how I think about it, and I seem to recall reading that beavior justified like this (don't ask me where though (might have been Dive Into Python, but maybe not)). That part is ok, I mean it doesn't confuse me I just wanted to say that this is somewhat confusing behavior. I agree that its not best put... But I was thinking about the last part of the post, the part that talks about trying to print a tuple and getting an error. -- http://mail.python.org/mailman/listinfo/python-list
Re: list in a tuple
Carl Banks wrote: On Dec 27, 12:38 pm, [EMAIL PROTECTED] wrote: After some tought I must agree that this is a wart more than a bug and that it will probably be best not to mess with it. However, what do you guys think about the print wart in Py3k described athttp://filoxus.blogspot.com/2007/12/python-3000-how-mutable-is-immuta... (im not trying to advertise my blog, I just don't feel like typing the whole problem all over again)? 1. Tuples are immutable. None of the tuples in your example were modified. The behavior you want (which is not immutability of tuples, which Python already has, but *recursive* immutability of all objects contained within the tuple) is not an unreasonable thing to ask for, but the design of Python and common usage of tuples makes it all but impossible at this point. There is no general way to determine whether an object is mutable or not. (Python would have to add this capability, an extremely substantial change, to grant your wish. It won't happen.) like I said, I don't think that this behavior should be changed... therefore, no wish-granting is needed, thank you :) Tuples are used internally to represent the arguments of a function, which are often mutable. Tuples are sometimes used to return multiple values from a function, which could include mutable values. Tuples are used to specify multiple arguments to a format string, some of which could be mutable, though I guess this is going away in Python 3. 2. The issue with print in your example is a bug, not a wart. It'll be fixed. (This is just a guess, but I think it might have something to do with the flux of the new bytes type. The behavior manifested itself when trying to print a self-referencing structure probably only because that section of code was lagging behind.) 3. You're still top posting, which goes against this group's conventions and annoys quite a few people. When you reply to a message, please move your cursor to below the quoted message before you begin typing. Thank you sorry for top posting... -- http://mail.python.org/mailman/listinfo/python-list
list in a tuple
Recently, I got into a debate on programming.reddit.com about what should happen in the following case: a = ([1], 2) a[0] += [3] Currently, Python raises an error *and* changes the first element of the tuple. Now, this seems like something one would want to change - why raise an error *and* execute the thing it was complaining about? The discussion seems to have no end, and that is why I'm posting here. I would like to know what is the opinion of the people on this group... Am I really mistaking for thinking that this is strange and unwanted behavior? Btw I understand *why* is this happening, I just think it should change... And here is the post that started this discussion: http://filoxus.blogspot.com/2007/12/python-3000-how-mutable-is-immutable.html#links Thanks for your replies -- http://mail.python.org/mailman/listinfo/python-list
Re: list in a tuple
Like I said, it is clear *why* this happens, what I
am concerned is if this what we *want* to happen, i.e.,
if the current situation is satisfying. Your mytuple class
would be something that resembles a solution, my question
is what the people on this group think about it.
On Dec 24, 5:08 pm, Arnaud Delobelle [EMAIL PROTECTED] wrote:
On Dec 24, 3:22 pm, [EMAIL PROTECTED] wrote:
Recently, I got into a debate on programming.reddit.com about
what should happen in the following case:
a = ([1], 2)
a[0] += [3]
Currently, Python raises an error *and* changes the first element of
the tuple. Now, this seems like something one would want to
change - why raise an error *and* execute the thing it
was complaining about? The discussion seems to have no end, and
that is why I'm posting here. I would like to know what is the opinion
of the people on this group... Am I really mistaking for thinking that
this is strange and unwanted behavior? Btw I understand *why* is this
happening, I just think it should change...
And here is the post that started this
discussion:http://filoxus.blogspot.com/2007/12/python-3000-how-mutable-is-immuta...
Thanks for your replies
For the sake of clarity, say you have typed:
L = [1]
a = (L, 2)
a[0] += [3]
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: 'tuple' object does not support item assignment a
([1, 3], 2)
I think that this is what happens when a[0] += [3] is executed:
1. list.__iadd__(L, [3]) is called, modifying L in place and returning
L.
2. tuple.__setitem__(a, L) is tried, raising the TypeError.
Notice that this problem doesn't arise when replacing lists with
tuples:
a = ( (1,), 2)
a[0] += (3, )
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: 'tuple' object does not support item assignment a
((1,), 2)
This is because tuple object don't have an __iadd__ method so a new
object tuple.__add__((1,),(3,)) is created and returned.
AFAICS, the only way to avoid the error message would be to check if
the new object is the same as the old one before raising the
TypeError:
class mytuple(tuple):
It's ok to do t[i] = obj as long as t[i] was already obj
def __setitem__(self, i, val):
if self[i] is not val:
raise TypeError('mytuple' object is immutable)
So:
a = mytuple(([1], 2))
a[0] += [3] # This now works
a[1] += 4 # This won't work as ints are immutable
Traceback (most recent call last):
File stdin, line 1, in module
File tuple.py, line 4, in __setitem__
raise TypeError('mytuple' object is immutable)
TypeError: 'mytuple' object is immutable a
([1, 3], 2)
It wouldn't slow anything down I suppose, just make some currently
failing code succeed.
--
Arnaud
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sorting dict keys
On 21 srp, 02:31, Steven D'Aprano [EMAIL PROTECTED] wrote: On Fri, 20 Jul 2007 15:27:51 -0700, montyphyton wrote: b = a.keys() b.sort() [1, 2, 3] Works fine, but I would really like it if I could somehow do it in one line. Why? Is the Enter key on your keyboard broken? Is there a global shortage of newline characters that I haven't been told about? Does your employer pay you less if you write more lines? -- Steven. I'd like to do it in one line because what I am trying to do is, after all, a single, simple enough action. I find the suggested b = sorted(a.keys()) much more readable than breaking it up in two lines. In the long run, I guess it's a matter of personal taste... Do I get payed less for more source code? Since I'm a student, I don't get payed at all, regardless of number of lines :) -- http://mail.python.org/mailman/listinfo/python-list
Sorting dict keys
Consider the following:
a = {1:2, 3:4, 2:5}
Say that i want to get the keys of a, sorted. First thing I tried:
b = a.keys().sort()
print b
None
Doesn't work. Probably because I am actually trying to sort the keys
of the dictionary without copying them first. If that is the case,
fine. Next thing I do:
b = a.keys()
b.sort()
[1, 2, 3]
Works fine, but I would really like it if I could somehow do it in one
line. As the problem seems to be copying the object, i try the
following:
import copy
b = copy.copy(a.keys()).sort()
print b
None
Hmmm, why doesn't it work? Also,
b = copy.deepcopy(a.keys()).sort()
print b
None
(not that I thought that deepcopy will work since shallow didn't, I
understand the difference :) )
Obviously, I am missing something here. What am I thinking wrong? Why
doesn't copying the object work?
Thanks for all the help
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sorting dict keys
On 21 srp, 00:47, Duncan Smith [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
Consider the following:
a = {1:2, 3:4, 2:5}
Say that i want to get the keys of a, sorted. First thing I tried:
b = a.keys().sort()
print b
None
Doesn't work. Probably because I am actually trying to sort the keys
of the dictionary without copying them first. If that is the case,
fine. Next thing I do:
b = a.keys()
b.sort()
[1, 2, 3]
Works fine, but I would really like it if I could somehow do it in one
line. As the problem seems to be copying the object, i try the
following:
import copy
b = copy.copy(a.keys()).sort()
print b
None
Hmmm, why doesn't it work? Also,
b = copy.deepcopy(a.keys()).sort()
print b
None
(not that I thought that deepcopy will work since shallow didn't, I
understand the difference :) )
Obviously, I am missing something here. What am I thinking wrong? Why
doesn't copying the object work?
Thanks for all the help
sort() sorts a list in place and returns None. For a one-liner:
a = {1:2, 3:4, 2:5}
b = sorted(a.keys())
b
[1, 2, 3]
Duncan
Thanks, this is what I was looking for. I know that .sort() sorts the
list in-place (the snippet I posted was written in a hurry, not pasted
-- I apologise for that). In fact, this is exactly what puzzles me.
copy.copy returns a new object:
copy.copy(a.keys())
[1,2,3]
Then why doesn't copy.copy(a.keys()).sort() work??
Thanks to everyone who replied!
--
http://mail.python.org/mailman/listinfo/python-list
Re: which GUI module you suggest me to use?
This completely loses me; what do you mean by draw its own icon, and what does that have to do with rendering Web pages? maybe draw its own icons wasn't the best (or the most accurate way) of putting it. what i meant by that is this (from wikipedia): Qt uses its own paint engine and controls. This makes the work of porting to other platforms easier because very few classes in Qt depended on the target platform. Qt used to emulate the native look of its intended platforms, which occasionally led to slight discrepancies where that emulation wasn't perfect. This, however, no longer applies because the latest versions of Qt use the native styles API of the different platforms to draw the Qt controls. what does that have to do with rendering web pages? have no idea. i just wanted to point out the main difference between qt and wx that he should be aware of. -- http://mail.python.org/mailman/listinfo/python-list
Re: Determinant of Large Matrix
James Stroud je napisao/la: Hello All, I'm using numpy to calculate determinants of matrices that look like this (13x13): [[ 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.] [ 1. 0. 1. 4. 1. 9. 4. 4. 1. 1. 4. 9. 4. 9.] [ 1. 1. 0. 1. 4. 4. 9. 9. 4. 4. 1. 4. 1. 4.] [ 1. 4. 1. 0. 9. 1. 4. 4. 9. 1. 4. 1. 4. 1.] [ 1. 1. 4. 9. 0. 4. 4. 4. 1. 4. 1. 9. 4. 9.] [ 1. 9. 4. 1. 4. 0. 4. 4. 9. 4. 1. 1. 4. 1.] [ 1. 4. 9. 4. 4. 4. 0. 1. 1. 1. 9. 1. 9. 4.] [ 1. 4. 9. 4. 4. 4. 1. 0. 4. 1. 9. 4. 4. 1.] [ 1. 1. 4. 9. 1. 9. 1. 4. 0. 4. 4. 4. 4. 9.] [ 1. 1. 4. 1. 4. 4. 1. 1. 4. 0. 9. 4. 9. 4.] [ 1. 4. 1. 4. 1. 1. 9. 9. 4. 9. 0. 4. 1. 4.] [ 1. 9. 4. 1. 9. 1. 1. 4. 4. 4. 4. 0. 4. 1.] [ 1. 4. 1. 4. 4. 4. 9. 4. 4. 9. 1. 4. 0. 1.] [ 1. 9. 4. 1. 9. 1. 4. 1. 9. 4. 4. 1. 1. 0.]] For this matrix, I'm getting this with numpy: 2774532095.971 But I have a feeling I'm exceeding the capacity of floats here. Does anyone have an idea for how to treat this? Is it absurd to think I could get a determinant of this matrix? Is there a python package that could help me? Many thanks for any answers. James have you tried using matlab to verify the result? matlab is very fast and can work with large matrices, so this should be no problem for it... -- http://mail.python.org/mailman/listinfo/python-list
Re: Who uses Python?
i use it for text mining, processing large text corpora for scientific purposes. i'm also working on some neat data mining tools written in python (called orange, in case someone's interested) walterbyrd je napisao/la: I mean other than sysadmins, programmers, and web-site developers? I have heard of some DBAs who use a lot of python. I suppose some scientists. I think python is used in bioinformatics. I think some math and physics people use python. I suppose some people use python to learn programming in general. Python would do well as a teaching language. I would think that python would be a good language for data analysis. Anything else? Finance? Web-analytics? SEO? Digital art? -- http://mail.python.org/mailman/listinfo/python-list
Re: which GUI module you suggest me to use?
ZioMiP je napisao/la: Hi to all... I'm actually using Tkinter for my GUI... but I need to put a piece of a web-page in a widget how can I do? which GUI module do you suggest me to use for do that? or which GUI module do you suggest me to use at all? I'm acutally using Windows Xp but I also use Linux... I know that WxPython work only under Windows and PyGTK work only under Linux... there's some other modules? have you considered using qt, i.e., pyqt, pyqwt? unlike wx, qt draws its own icons... -- http://mail.python.org/mailman/listinfo/python-list
Re: Python, Dutch, English, Chinese, Japanese, etc.
Steve Howell je napisao/la: some European alphabets: Spanish -- accented, includes digraphs ch and ll German -- accented French -- accented Italian -- accented, no J/K/W/X/Y what about slavic languages? in croatian you have five accented letters plus three letters for digrahps. russian, bulgarian, serbian, macedonian, ukranian etc. use cyrilic alphabet (lets not forget that russia isn't that small - around 150 million people), polish also has some of its own characters... all in all, it is estimated that some 400 million people speak slavic languages... -- http://mail.python.org/mailman/listinfo/python-list
Re: Python, Dutch, English, Chinese, Japanese, etc.
Agreed, but FWIW, if you compared Slavic-writing people to Chinese-writing people, I would think that a higher percentage of Slavic-writing people would be bilingual in terms of their ability to write code in non-Slavic alphabets, due to various cultural/geographical factors. of course. but maybe it would be a nice effort to enable writing code in cyrillic, since it is a whole new alphabet. for the accented letters from slavic (or other) languages, i agree that one wouldn't gain much from enabling their use in source code. but my point being, if we are going to add chinese and japanese, why not do everything right and add all languages/alphabets? after all, after adding chinese, how hard can it be to add a few accedented letters :) I don't predict a huge upswing in Slavic-writing Python programmers after PEP 3131, even among children. you are probably right. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python, Dutch, English, Chinese, Japanese, etc.
Méta-MCI je napisao/la: Et le klingon ? Please, don't forget klingons SVP, n'oubliez pas les klingons ;o) je pense que le klingon utilise les mems lettres comme l'anglais -- http://mail.python.org/mailman/listinfo/python-list
Re: how can I get the name of a method inside it?
I would like to know if it's possible to retrieve the name of a method when you're inside it. For example, in the following script, I would like to assign _s so that it prints you are in method1. *** class Obj1: def __init__(self): ... def method1(self): _s = ??? print you are in %s % _s x = Obj1() x.method1() i'm no expert on the subject, but AFAIK, there's no way to do this. why not just print you are in method1? what are you exactly trying to do? -- http://mail.python.org/mailman/listinfo/python-list
PEP 8 style enforcing program
Some recent posts about Python programming style got me thinking. Since we have the PEP 8 which gives some guidelines about the style to be used, do we have any program that can check for violations of these guidelines within the source code? I understand that there are a lot of code beautifiers out there, but i haven't seen one specially tailored for Python... Is there even a desire in Python community for a program like this (by Python community I mean the people in this group:) ) ? I think it would be a nice little project for practice and I'd like to do it, but if there is already something like this then I can probably spend my time on something more productive. So, I'd like to hear your opinion on this... There is one thing that I don't understand about PEP 8 - why is using spaces considered more desirable than using tabs for indentation? -- http://mail.python.org/mailman/listinfo/python-list
writing to a file
as i understand there are two ways to write data to a file: using f.write(foo) and print f, foo. what i want to know is which one is faster (if there is any difference in speed) since i'm working with very large files. of course, if there is any other way to write data to a file, i'd love to hear about it -- http://mail.python.org/mailman/listinfo/python-list
