Re: ImSim: Image Similarity
At least you could've tried to make the script more usable by adding the possibility to supply command line arguments, instead of editing the source every time you want to compare a couple of images. On Sat, Mar 5, 2011 at 11:23 AM, n00m wrote: > Let me present my newborn project (in Python) ImSim: > > http://sourceforge.net/projects/imsim/ > > Its README.txt: > - > ImSim is a python script for finding the most similar pic(s) to > a given one among a set/list/db of your pics. > The script is very short and very easy to follow and understand. > Its sample output looks like this: > > bears2.jpg > > bears2.jpg 0.00 > bears3.jpg 55.33 > bears1.jpg 68.87 > sky1.jpg 83.84 > sky2.jpg 84.41 > ff1.jpg 91.35 > lake1.jpg 95.14 > water1.jpg 96.94 > ff2.jpg 102.36 > roses1.jpg 115.02 > roses2.jpg 130.02 > > Done! > > The *less* numeric value -- the *more similar* this pic is to the > tested pic. If this value > 70 almost for sure these pictures are > absolutely different (from totally different domains, so to speak). > > What is "similarity" and how can/could/should it be estimated this > point I'm leaving for your consideration/contemplation/arguing etc. > > Several sample pics (*.jpg) are included into .zip. > And of course the stuff requires PIL (Python Imaging Library), see: > Home-page: http://www.pythonware.com/products/pil > Download-URL: http://effbot.org/zone/pil-changes-116.htm > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: Fun with 'str' and 'bytes'
On Mar 4, 6:40 pm, nn wrote:
> On Mar 4, 7:32 am, "Frank Millman" wrote:
>
> > Hi all
>
> > I want to create a cookie containing a session id. In python 2.6 I had the
> > following -
>
> > from __future__ import unicode_literals
> > session_id = b64encode(urandom(20))
> > response_headers.append(
> > (b'Set-Cookie', b'sid="{0}"'.format(session_id)))
>
> > After upgrading to 3.2, the above lines generate this traceback -
> > AttributeError: 'bytes' object has no attribute 'format'
>
> > The best workaround I can come up with is the following -
>
> > session_id = b64encode(urandom(20))
> > response_headers.append(
> > (b'Set-Cookie', b'sid="' + session_id + b'"'))
>
> > It works, but it is not pretty. Is there a more elegant solution?
>
> > Thanks
>
> > Frank Millman
>
> As far as I know, that is pretty much it. Also see:
>
> http://bugs.python.org/issue3982http://mail.python.org/pipermail/python-dev/2010-July/102252.htmlhttp://lucumr.pocoo.org/2010/5/25/wsgi-on-python-3/
Thanks for the response, and for the links - interesting reading.
Frank
--
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Re: questions about multiprocessing
Got it.
After putting commas, it works (The 'o' was a mistake when I posted,
sorry about it ).
Thanks to all of you :)
On Mar 5, 5:12 pm, Dennis Lee Bieber wrote:
> On Fri, 4 Mar 2011 20:08:21 -0800 (PST), Vincent Ren
> declaimed the following in
> gmane.comp.python.general:
>
> > Hello, everyone, recently I am trying to learn python's
> > multiprocessing, but
> > I got confused as a beginner.
>
> > If I run the code below:
>
> > from multiprocessing import Pool
> > import urllib2
> > otasks = [
> > 'http://www.php.net'
> > 'http://www.python.org'
> > 'http://www.perl.org'
> > 'http://www.gnu.org'
> > ]
>
> You've just defined a list with ONE element -- a string of:
>
> "http://www.php.nethttp://www.python.orghttp://www.perl.orghttp://http...";
>
> Python concatenates adjacent strings -- which includes those on
> multiple lines when inside an open ( [ { structure.
>
> You need to put commas after the closing quotes on those lines.
>
> > def f(url):
> > return urllib2.urlopen(url).read()
>
> > pool = Pool(processes = 2)
> > print pool.map(f, tasks)
>
> And I'm presuming the others are correct -- and that should be
>
> (f, otasks)
>
> > httplib.InvalidURL: nonnumeric port: ''
>
> No surprise... URL nomenclature expects a port number after the
> second : in URL, and with concatenation you've got four : in a single
> URL.
> --
> Wulfraed Dennis Lee Bieber AF6VN
> wlfr...@ix.netcom.com HTTP://wlfraed.home.netcom.com/
--
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Re: Problems of Symbol Congestion in Computer Languages
On Mar 1, 3:40 pm, Chris Jones wrote:
> At first it looks like something MS (Morgan Stanley..) dumped into the
> OSS lap fifteen years ago and nobody ever used it or maintained it.. so
> it takes a bit of digging to make it.. sort of work in current GNU/linux
> distributions.. especially since it knows nothing about Unicode.
>
> Here's the X/A+ map I came up with:
>
> // A+ keyboard layout: /usr/share/X11/xkb/symbols/apl
> // Chris Jones - 18/12/2010
>
> // Enable via:
> // $ setxkbmap -v 10 apl
>
> default
> partial alphanumeric_keys modifier_keys
> xkb_symbols "APL" {
>
> name[Group1]= "APL";
>
> // Alphanumeric section
> key { [ grave, asciitilde, 0x01fe, 0x017e
> ] };
> key { [ 1, exclam, 0x01a1, 0x01e0
> ] };
> key { [ 2, at, 0x01a2, 0x01e6
> ] };
> key { [ 3, numbersign, 0x013c, 0x01e7
> ] };
> key { [ 4, dollar, 0x01a4, 0x01e8
> ] };
> key { [ 5, percent, 0x013d, 0x01f7
> ] };
> key { [ 6, asciicircum, 0x01a6, 0x01f4
> ] };
> key { [ 7, ampersand, 0x013e, 0x01e1
> ] };
> key { [ 8, asterisk, 0x01a8, 0x01f0
> ] };
> key { [ 9, parenleft, 0x01a9, 0x01b9
> ] };
> key { [ 0, parenright, 0x015e, 0x01b0
> ] };
> key { [ minus, underscore, 0x01ab, 0x0121
> ] };
> key { [ equal, plus, 0x01df, 0x01ad
> ] };
>
> key { [ q, Q, 0x013f, 0x01bf
> ] };
> key { [ w, W, 0x01d7, Nosymbol
> ] };
> key { [ e, E, 0x01c5, 0x01e5
> ] };
> key { [ r, R, 0x01d2, Nosymbol
> ] };
> key { [ t, T, 0x017e, Nosymbol
> ] };
> key { [ y, Y, 0x01d9, 0x01b4
> ] };
> key { [ u, U, 0x01d5, Nosymbol
> ] };
> key { [ i, I, 0x01c9, 0x01e9
> ] };
> key { [ o, O, 0x01cf, 0x01ef
> ] };
> key { [ p, P, 0x012a, 0x01b3
> ] };
> key { [ bracketleft, braceleft, 0x01fb, 0x01dd
> ] };
> key { [ bracketright, braceright, 0x01fd, 0x01db
> ] };
>
> key { [ a, A, 0x01c1, Nosymbol
> ] };
> key { [ s, S, 0x01d3, 0x01be
> ] };
> key { [ d, D, 0x01c4, Nosymbol
> ] };
> key { [ f, F, 0x015f, 0x01bd
> ] };
> key { [ g, G, 0x01c7, 0x01e7
> ] };
> key { [ h, H, 0x01c8, 0x01e8
> ] };
> key { [ j, J, 0x01ca, 0x01ea
> ] };
> key { [ k, K, 0x0127, Nosymbol
> ] };
> key { [ l, L, 0x01cc, 0x01ec
> ] };
> key { [ semicolon, colon, 0x01db, 0x01bc
> ] };
> key { [ apostrophe, quotedbl, 0x01dd, 0x01bb
> ] };
>
> key { [ z, Z, 0x01da, 0x01fa
> ] };
> key { [ x, X, 0x01d8, Nosymbol
> ] };
> key { [ c, C, 0x01c3, 0x01e3
> ] };
> key { [ v, V, 0x01d6, Nosymbol
> ] };
> key { [ b, B, 0x01c2, 0x01e2
> ] };
> key { [ n, N, 0x01ce, 0x01ee
> ] };
> key { [ m, M, 0x017c, 0x01cd
> ] };
> key { [ comma, less, 0x01ac, 0x013c
> ] };
> key { [ period, greater, 0x01dc, 0x01ae
> ] };
> key { [ slash, question, 0x01af, 0x013f
> ] };
>
> key { [ backslash, bar, 0x01dc, 0x01fc
> ] };
> key { [ Caps_L
Re: getting text out of an xml string
On Mar 5, 8:57 am, JT wrote: > On Mar 4, 9:30 pm, John Machin wrote: > > > Your data has been FUABARred (the first A being for Almost) -- the > > "\u3c00" and "\u3e00" were once "<" and ">" respectively. You will > > Hi John, > > I realized that a few minutes after posting. I then realized that > I could just extract the text between the stuff with \u3c00 xml > preserve etc, which I did; it was good enough since it was a one-off > affair, I had to convert a to-do list from one program to another. > Thanks for replying and sorry for the noise :-) Next time you need to extract some data from an xml file, please (for your own good) don't do whatever you did in that code -- note that the unicode equivalent of "<" is u"\u003c", NOT u"\u3c00"; I wasn't joking when I said it had been FU. -- http://mail.python.org/mailman/listinfo/python-list
Re: What do I need to know in order to write a web application in python?
Visual Python seems to be exactly what I want. But it doesn't seem very popular. Perhaps it means that there are not many people who will be able to help if I have problems with it. Also judging by the amount of ads at visualpython.org, it also doesn't seem very serious. I looked into pyGTK, and I found something called "Glade", which seems to be something similar to visual python. The latest version of Glade was released just this month, so it seems to be actively developed. Regarding Boa constructor, it is very old, isn't it? The latest news from this project date to the end of 2006. I don't expect it to support python 3 any time soon. So, "Glade", is this what everybody uses? I mean programmers don't just use text editors to make GUI applications, do they? > That site appears to require a monthly fee, so it may not be a good > vehicle for demonstrating requirements to a broad audience. Actually you can play 10 games per day for free, or at least it was like that when I used it last time. Just enter some random name and press "start game". -- http://mail.python.org/mailman/listinfo/python-list
Re: Generate PDF with Tamil font problem
sathe...@e-ndicus.com wrote: >I am using python's reportlab to print some unicode Tamil characters > 'பே'. I added necessary unicode font to reportlab. But It > prints the output as 'ேப' (in reverse order). This issue > happens for multi-byte characters, whereas for character 'ப' is > printed as it is. > I am struggling to figure out the issue. Any help would see me on track. Something similar came up on stackoverflow recently, though that was with tkinter. Might shed some light. http://stackoverflow.com/questions/5166488/ -- Tom Zych / freethin...@pobox.com "Would you like a lovely fluffy little white rabbit, little girl, or a cutesy wootesly little brown rabbit?" "Actually, I don't think my python would notice." -- http://mail.python.org/mailman/listinfo/python-list
Re: Problems of Symbol Congestion in Computer Languages
In article , Dotan Cohen wrote: >You miss the canonical bad character reuse case: = vs ==. > >Had there been more meta keys, it might be nice to have a symbol for >each key on the keyboard. I personally have experimented with putting >the symbols as regular keys and the numbers as the Shifted versions. >It's great for programming. People might be interested in the colorforth solution: This goes the other way: characters are limited (lowercase and few special chars) to what is needed for programming. So the fingers never need to leave the home position, reaching about 30 chars at most. Different uses (defining a function versus using a function) are indicated by color, so don't use up char's. http://www.colorforth.com I was forced to use it (a development environment required it) and it is not as bad as it sounds. >-- >Dotan Cohen Groetjes Albert -- -- Albert van der Horst, UTRECHT,THE NETHERLANDS Economic growth -- being exponential -- ultimately falters. albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with python 3.2 and circular imports
Thank you for your answer Frank, I think I've found the problem. I was calling modules from inside subpackages, and I need to use them from outside, so I have package in PYTHONPATH. is that correct? But now I have another question: Can I execute an script inside subpackage1 importig modules from subpackage2? 2011/3/4 Frank Millman > > On February 28 2011 Rafael Durán Castañeda wrote > > I'm stil totally stuck with relative imports, i' ve tried the example tree >> from PEP 328 without any result: >> >> package/ >> __init__.py >> subpackage1/ >> __init__.py >> moduleX.py >> moduleY.py >> subpackage2/ >> __init__.py >> moduleZ.py >> moduleA.py >> >> Assuming that the current file is either moduleX.py or >> subpackage1/__init__.py, following are correct usages of the new >> syntax: >> >> from .moduleY import spam >> from .moduleY import spam as ham >> from . import moduleY >> from ..subpackage1 import moduleY >> from ..subpackage2.moduleZ import eggs >> from ..moduleA import foo >> from ...package import bar >> from ...sys import path >> >> I always get: >> >> Traceback (most recent call last): >> File "moduleY.py", line 1, in >> from ..moduleA import a >> ValueError: Attempted relative import in non-package >> >> >> > Hi Rafael > > I only just noticed your message now. For some reason it did not appear on > google.groups. > > I just tried it and it worked for me. This is what I did. > > I set up the above structure. I added a 'def spam()' to moduleY, 'def > eggs()' to moduleZ, and 'def foo()' to moduleA. > > I pasted all of the 'from ... import ...' lines above into moduleX. > > In the same directory that contains the subdirectory 'package' I create a > test script containing the following line - > import package.subpackage1.moduleX > > To begin with it failed on the last two lines starting with 'from ...' [how > do you indicate three dots followed by etc etc, which would normally be > indicated by three dots!]. The traceback said 'Attempted relative import > beyond toplevel package'. > > I did not want to investigate too deeply so I just commented those lines > out, and now it runs with no errors. I even put a couple of print statements > (or must I call them print functions now) into the modules being imported, > and the messages do appear, so the modules are being imported. > > HTH > > Frank Millman > > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: What do I need to know in order to write a web application in python?
On 03/05/2011 06:49 AM, ErichCart ErichCart wrote: > So, "Glade", is this what everybody uses? I mean programmers don't > just use text editors to make GUI applications, do they? I usually see people using Qt and QtDesigner over Gtk and Glade. And actually, yes, I'm sure lots of people besides me actually make their GUI apps in a text editor. Then again, I usually don't do anything big. If you want to learn your GUI toolkit well, do it by hand and not by tool. As someone said to me once, "QtDesigner is meant for people who already know how to use Qt". I'm sure the same applies for Glade. -- Corey Richardson -- http://mail.python.org/mailman/listinfo/python-list
RE: python xmp toolkit question
>In article <20110304161955.LI5T1.94538.root at cdptpa-web16-z02>, > wrote: >> Is anyone here using the Python XMP Toolkit? I'm trying to install >> this and having problems. >> > I have no experience with either but I would guess that the two > configure options are for building with Boost installed from MacPorts > (the newer name for DarwinPorts) or from Fink. MacPorts and Fink are > two open-source projects that port and distribute many third-party > packages to Mac OS X. My personal preference is for MacPorts. If you >don't already have the necessary current MacPorts base files installed, > follow the instructions here: http://www.macports.org/install.php > MacPorts installs everything under /opt/local so you will need to add > /opt/local/bin to the front of your shell search PATH. Then you can > pick a Python version (MacPorts will install its own version) and the > Boost variant to go with it: > $ sudo port selfupdate > $ sudo port install python27 > $ sudo port install python_select > $ sudo /opt/local/bin/python_select python27 > $ sudo port install boost +python27 > In fact, MacPorts has a port file for Exempi itself > (http://www.macports.org/ports.php?by=name&substr=exempi) > $ sudo port install exempi > Then, using the MacPorts python you installed, you should be able to > easily install the toolkit. Good luck! > -- > Ned Deily, > nad at acm.org Hi Ned, Thank you very much for your reply. When I get back to work Monday I will give this a try… this looks to be exactly what I needed! Thanks. Jay -- http://mail.python.org/mailman/listinfo/python-list
Re: What do I need to know in order to write a web application in python?
On Mar 5, 6:49 am, ErichCart ErichCart wrote: > Regarding Boa constructor, it is very old, isn't it? The latest news > from this project date to the end of 2006. I don't expect it to > support python 3 any time soon. The website is incredibly out of date, but the last major update was July 2007. So, yes. Like any snake, it could suddenly rear up and spring to life with a new version, but there is no way to know when or if that will happen. Even wxPython itself doesn't support Python 3 yet, so I'm not sure I'd let that deter you. It seems like many third party libraries haven't updated to Python 3 yet and may not for some time to come. All this said, one can build a toy GUI application using Boa, Python 2.5 or 2.6 and wxPython 2.8.x.x. in 5 minutes if you know what you're doing. And you can build a larger and real application that way, too. -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
I uploaded a new version of the subject with a VERY MINOR correction in it. Namely, in line #55: print '%12s %7.2f' % (db[k][1], db[k][0] / 3600.0,) instead of print '%12s %7.2f' % (db[k][1], db[k][0] * 0.001,) I.e. I normalized it to base = 100. Now the values of similarity can't be greater than 100 and can be treated as some "regular" percents (%%). Also, due to this change, the *empirical* threshold of "system alarmity" moved down from "number 70" to "20%". bears2.jpg bears2.jpg0.00 bears3.jpg 15.37 bears1.jpg 19.13 sky1.jpg 23.29 sky2.jpg 23.45 ff1.jpg 25.37 lake1.jpg 26.43 water1.jpg 26.93 ff2.jpg 28.43 roses1.jpg 31.95 roses2.jpg 36.12 Done! -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
n00m wrote:
>
> I uploaded a new version of the subject with a
> VERY MINOR correction in it. Namely, in line #55:
>
> print '%12s %7.2f' % (db[k][1], db[k][0] / 3600.0,)
>
> instead of
>
> print '%12s %7.2f' % (db[k][1], db[k][0] * 0.001,)
>
> I.e. I normalized it to base = 100.
> Now the values of similarity can't be greater than 100
> and can be treated as some "regular" percents (%%).
>
> Also, due to this change, the *empirical* threshold of
> "system alarmity" moved down from "number 70" to "20%".
>
> bears2.jpg
>
> bears2.jpg0.00
> bears3.jpg 15.37
> bears1.jpg 19.13
> sky1.jpg 23.29
> sky2.jpg 23.45
> ff1.jpg 25.37
>lake1.jpg 26.43
> water1.jpg 26.93
> ff2.jpg 28.43
> roses1.jpg 31.95
> roses2.jpg 36.12
I'd like to see a *lot* more structure in there, with modularization, so the
internal functions could be used from another program. Once I'd figured out
what it was doing, I had this:
from PIL import Image
from PIL import ImageStat
def row_column_histograms (file_name):
'''Reduce the image to a 5x5 square of b/w brightness levels 0..3
Return two brightness histograms across Y and X
packed into a 10-item list of 4-item histograms.'''
im = Image.open (file_name)
im = im.convert ('L') # convert to 8-bit b/w
w, h = 300, 300
im = im.resize ((w, h))
imst = ImageStat.Stat (im)
sr = imst.mean[0] # average pixel level in layer 0
sr_low, sr_mid, sr_high = (sr*2)/3, sr, (sr*4)/3
def foo (t):
if t < sr_low: return 0
if t < sr_mid: return 1
if t < sr_high: return 2
return 3
im = im.point (foo) # reduce to brightness levels 0..3
yhist = [[0]*4 for i in xrange(5)]
xhist = [[0]*4 for i in xrange(5)]
for y in xrange (h):
for x in xrange (w):
k = im.getpixel ((x, y))
yhist[y / 60][k] += 1
xhist[x / 60][k] += 1
return yhist + xhist
def difference_ranks (test_histogram, sample_histograms):
'''Return a list of difference ranks between the test histograms and
each of the samples.'''
result = [0]*len (sample_histograms)
for k, s in enumerate (sample_histograms): # for each image
for i in xrange(10):# for each histogram slot
for j in xrange(4): # for each brightness level
result[k] += abs (s[i][j] - test_histogram[i][j])
return result
if __name__ == '__main__':
import getopt, sys
opts, args = getopt.getopt (sys.argv[1:], '', [])
if not args:
args = [
'bears1.jpg',
'bears2.jpg',
'bears3.jpg',
'roses1.jpg',
'roses2.jpg',
'ff1.jpg',
'ff2.jpg',
'sky1.jpg',
'sky2.jpg',
'water1.jpg',
'lake1.jpg',
]
test_pic = 'bears2.jpg'
else:
test_pic, args = args[0], args[1:]
z = [row_column_histograms (a) for a in args]
test_z = row_column_histograms (test_pic)
file_ranks = zip (difference_ranks (test_z, z), args)
file_ranks.sort()
print '%12s' % (test_pic,)
print ''
for r in file_ranks:
print '%12s %7.2f' % (r[1], r[0] / 3600.0,)
(omitting a few comments that wrapped around.) The test-case still agrees
with your archived version:
mwilson@tecumseth:~/sandbox/im_sim$ python image_rank.py bears2.jpg *.jpg
bears2.jpg
bears2.jpg0.00
bears3.jpg 15.37
bears1.jpg 19.20
sky1.jpg 23.20
sky2.jpg 23.37
ff1.jpg 25.30
lake1.jpg 26.38
water1.jpg 26.98
ff2.jpg 28.43
roses1.jpg 32.01
I'd vaguely wanted to do something like this for a while, but I never dug
far enough into PIL to even get started. An additional kind of ranking that
takes colour into account would also be good -- that's the first one I never
did.
Cheers, Mel.
--
http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
On Mar 5, 7:10 pm, Mel wrote:
> n00m wrote:
>
> > I uploaded a new version of the subject with a
> > VERY MINOR correction in it. Namely, in line #55:
>
> > print '%12s %7.2f' % (db[k][1], db[k][0] / 3600.0,)
>
> > instead of
>
> > print '%12s %7.2f' % (db[k][1], db[k][0] * 0.001,)
>
> > I.e. I normalized it to base = 100.
> > Now the values of similarity can't be greater than 100
> > and can be treated as some "regular" percents (%%).
>
> > Also, due to this change, the *empirical* threshold of
> > "system alarmity" moved down from "number 70" to "20%".
>
> > bears2.jpg
> >
> > bears2.jpg 0.00
> > bears3.jpg 15.37
> > bears1.jpg 19.13
> > sky1.jpg 23.29
> > sky2.jpg 23.45
> > ff1.jpg 25.37
> > lake1.jpg 26.43
> > water1.jpg 26.93
> > ff2.jpg 28.43
> > roses1.jpg 31.95
> > roses2.jpg 36.12
>
> I'd like to see a *lot* more structure in there, with modularization, so the
> internal functions could be used from another program. Once I'd figured out
> what it was doing, I had this:
>
> from PIL import Image
> from PIL import ImageStat
>
> def row_column_histograms (file_name):
> '''Reduce the image to a 5x5 square of b/w brightness levels 0..3
> Return two brightness histograms across Y and X
> packed into a 10-item list of 4-item histograms.'''
> im = Image.open (file_name)
> im = im.convert ('L') # convert to 8-bit b/w
> w, h = 300, 300
> im = im.resize ((w, h))
> imst = ImageStat.Stat (im)
> sr = imst.mean[0] # average pixel level in layer 0
> sr_low, sr_mid, sr_high = (sr*2)/3, sr, (sr*4)/3
> def foo (t):
> if t < sr_low: return 0
> if t < sr_mid: return 1
> if t < sr_high: return 2
> return 3
> im = im.point (foo) # reduce to brightness levels 0..3
> yhist = [[0]*4 for i in xrange(5)]
> xhist = [[0]*4 for i in xrange(5)]
> for y in xrange (h):
> for x in xrange (w):
> k = im.getpixel ((x, y))
> yhist[y / 60][k] += 1
> xhist[x / 60][k] += 1
> return yhist + xhist
>
> def difference_ranks (test_histogram, sample_histograms):
> '''Return a list of difference ranks between the test histograms and
> each of the samples.'''
> result = [0]*len (sample_histograms)
> for k, s in enumerate (sample_histograms): # for each image
> for i in xrange(10): # for each histogram slot
> for j in xrange(4): # for each brightness level
> result[k] += abs (s[i][j] - test_histogram[i][j])
> return result
>
> if __name__ == '__main__':
> import getopt, sys
> opts, args = getopt.getopt (sys.argv[1:], '', [])
> if not args:
> args = [
> 'bears1.jpg',
> 'bears2.jpg',
> 'bears3.jpg',
> 'roses1.jpg',
> 'roses2.jpg',
> 'ff1.jpg',
> 'ff2.jpg',
> 'sky1.jpg',
> 'sky2.jpg',
> 'water1.jpg',
> 'lake1.jpg',
> ]
> test_pic = 'bears2.jpg'
> else:
> test_pic, args = args[0], args[1:]
>
> z = [row_column_histograms (a) for a in args]
> test_z = row_column_histograms (test_pic)
>
> file_ranks = zip (difference_ranks (test_z, z), args)
> file_ranks.sort()
>
> print '%12s' % (test_pic,)
> print ''
> for r in file_ranks:
> print '%12s %7.2f' % (r[1], r[0] / 3600.0,)
>
> (omitting a few comments that wrapped around.) The test-case still agrees
> with your archived version:
>
> mwilson@tecumseth:~/sandbox/im_sim$ python image_rank.py bears2.jpg *.jpg
> bears2.jpg
>
> bears2.jpg 0.00
> bears3.jpg 15.37
> bears1.jpg 19.20
> sky1.jpg 23.20
> sky2.jpg 23.37
> ff1.jpg 25.30
> lake1.jpg 26.38
> water1.jpg 26.98
> ff2.jpg 28.43
> roses1.jpg 32.01
>
> I'd vaguely wanted to do something like this for a while, but I never dug
> far enough into PIL to even get started. An additional kind of ranking that
> takes colour into account would also be good -- that's the first one I never
> did.
>
> Cheers, Mel.
Very nice, Mel.
As for using color info...
my current strong opinion is: the colors must be forgot for good.
Paradoxically but "profound" elaboration and detailization can/will
spoil/undermine the whole thing. Just my current imo.
===
Vitali
--
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Extending dict (dict's) to allow for multidimensional dictionary
I can extend dictionary to allow for the my own special look-up tables. However now I want to be able to define multidimensional dictionary which supports look-up like this: d[1]['abc'][40] = 'dummy' and if d[1] and d[1][abc] raise KeyError just create them. for d[1] I can override __getitem__() but how to do the same for the d[1][abc]? -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending dict (dict's) to allow for multidimensional dictionary
I found a solution here: http://parand.com/say/index.php/2007/07/13/simple-multi-dimensional-dictionaries-in-python/ Please tell how good is it? -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending dict (dict's) to allow for multidimensional dictionary
Ravi wrote:
> I found a solution here:
>
> http://parand.com/say/index.php/2007/07/13/simple-multi-dimensional-
dictionaries-in-python/
>
> Please tell how good is it?
Follow the link to the cookbook and read Andrew Dalke's comment ;)
To spell it out:
>>> class D(dict):
... def __missing__(self, key):
... result = self[key] = D()
... return result
...
>>> d = D()
>>> d["a"]["b"]["c"] = 42
>>> d
{'a': {'b': {'c': 42}}}
This is not only simpler, it should also give you faster lookup when the key
already exists.
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Re: ImSim: Image Similarity
On Sat, 2011-03-05, Grigory Javadyan wrote: > At least you could've tried to make the script more usable by adding > the possibility to supply command line arguments, instead of editing > the source every time you want to compare a couple of images. > > On Sat, Mar 5, 2011 at 11:23 AM, n00m wrote: >> Let me present my newborn project (in Python) ImSim: >> >> http://sourceforge.net/projects/imsim/ >> >> Its README.txt: >> - >> ImSim is a python script for finding the most similar pic(s) to >> a given one among a set/list/db of your pics. >> The script is very short and very easy to follow and understand. >> Its sample output looks like this: ... >> The *less* numeric value -- the *more similar* this pic is to the >> tested pic. If this value > 70 almost for sure these pictures are >> absolutely different (from totally different domains, so to speak). >> >> What is "similarity" and how can/could/should it be estimated this >> point I'm leaving for your consideration/contemplation/arguing etc. So basically you're saying you won't tell the users what the program *does*. I don't get that. Is it better than this? - scale each image to 100x100 - go black&white in such a way that half the pixels are black - XOR the images and count the mismatches That takes care of JPEG quality, scaling and possibly gamma correction, but not cropping or rotation. I'm sure there are better, well-known algorithms. /Jorgen -- // Jorgen GrahnO o . -- http://mail.python.org/mailman/listinfo/python-list
Re: how to read the last line of a huge file???
Thanks for the pointer. Yes, it is a text file, but the mystery runs deeper: I later found that it works perfectly as written when I run it from IDLE or the Python shell, but it fails reliably when I run it from PyScripter 2.4.1 (an open source Python IDE)! So I suspect there's a PyScripter issue lurking in here. I'm next going to try the solution you propose - use only for legal offsets - and then retry it under both IDLE and PyScripter. Question: how do I use f.tell() to identify if an offset is legal or illegal? Thanks in advance Thomas Philips -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
> > Is it better than this? > - scale each image to 100x100 > - go black&white in such a way that half the pixels are black > - XOR the images and count the mismatches It's *much* better but I'm not *much* about to prove it. > I'm sure there are better, > well-known algorithms. The best well-known algorithm is to hire a man with good eyesight for to do the job of comparing, ranking and selecting the pictures. -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
PS For some reason they don't update the link to the last version. It's _20110306, here: http://sourceforge.net/projects/imsim/files/ I use Python 2.5 & PIL for Python 2.5 -- http://mail.python.org/mailman/listinfo/python-list
Re: What do I need to know in order to write a web application in python?
Grumman wrote: > On 3/4/2011 16:48, ErichCart ErichCart wrote: >> >> In fact this doesn't necessary need to be web application. For >> example I have a friend who uses Delphi, and he can create all >> sorts of windows applications easily, like he can see the window >> on the screen and he can place buttons, text fields, radio buttons >> etc. wherever he wants and then program the actions of each >> element. I was able to do the same with visual basic in one of my >> university classes. >> >> What do I need to know in order to be able to do the same with >> python? Which python modules/python development environments do I >> need to use? > > You might want to look at: http://visualpython.org/ Also www.dabodev.com -- --OKB (not okblacke) Brendan Barnwell "Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail." --author unknown -- http://mail.python.org/mailman/listinfo/python-list
Re: What do I need to know in order to write a web application in python?
On Sat, Mar 5, 2011 at 3:49 AM, ErichCart ErichCart wrote: > Visual Python seems to be exactly what I want. But it doesn't seem > very popular. Perhaps it means that there are not many people who will > be able to help if I have problems with it. Also judging by the amount > of ads at visualpython.org, it also doesn't seem very serious. > > I looked into pyGTK, and I found something called "Glade", which seems > to be something similar to visual python. The latest version of Glade > was released just this month, so it seems to be actively developed. > > Regarding Boa constructor, it is very old, isn't it? The latest news > from this project date to the end of 2006. I don't expect it to > support python 3 any time soon. > > So, "Glade", is this what everybody uses? I mean programmers don't > just use text editors to make GUI applications, do they? Yes, they do. It isn't that bad once you get used to it, and it beats the snot out of trying to maintain the insensible gibberish that some of the autogen tools put out. On a side note, you should check out pygui[0]- very, very nice GUI toolkit. Geremy Condra [0]: http://www.cosc.canterbury.ac.nz/greg.ewing/python_gui/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending dict (dict's) to allow for multidimensional dictionary
Ravi writes: > I can extend dictionary to allow for the my own special look-up > tables. However now I want to be able to define multidimensional > dictionary which supports look-up like this: > > d[1]['abc'][40] = 'dummy' Why do that anyway? You can use a tuple as a subscript: d[1,'abc',40] = 'dummy' -- http://mail.python.org/mailman/listinfo/python-list
Re: how to read the last line of a huge file???
On 3/5/2011 10:21 AM, tkp...@hotmail.com wrote: Question: how do I use f.tell() to identify if an offset is legal or illegal? Read backwards in binary mode, byte by byte, until you reach a byte which is, in binary, either 0xxx 11xx You are then at the beginning of an ASCII or UTF-8 character. You can copy the bytes forward from there into an array of bytes, then apply the appropriate codec. This is also what you do if skipping ahead in a UTF-8 file, to get in sync. Reading the last line or lines is easier. Read backwards in binary until you hit an LF or CR, both of which are the same in ASCII and UTF-8. Copy the bytes forward from that point into an array of bytes, then apply the appropriate codec. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: how to read the last line of a huge file???
On 3/5/2011 1:21 PM, tkp...@hotmail.com wrote: Thanks for the pointer. Yes, it is a text file, but the mystery runs deeper: I later found that it works perfectly as written when I run it from IDLE or the Python shell, but it fails reliably when I run it from PyScripter 2.4.1 (an open source Python IDE)! So I suspect there's a PyScripter issue lurking in here. I'm next going to try the solution you propose - use only for legal offsets - and then retry it under both IDLE and PyScripter. Question: how do I use f.tell() to identify if an offset is legal or illegal? I do not believe you can. You have to be at a position and f.tell() will report it. Note: if a file is utf-8 encoded, and you seek to an arbitrary position in binary mode, it is easy to synchronize by discarding the remainder (if any)of a multibyte char and finding the start of the next char. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: getting text out of an xml string
> Next time you need to extract some data from an xml file, please (for > your own good) don't do whatever you did in that code -- note that the > unicode equivalent of "<" is u"\u003c", NOT u"\u3c00"; I wasn't joking > when I said it had been FU. Is that perhaps the doing of going from littleEndian to bigEndian (or vice versa) machines with that file, in some kind of strange binary mode? /björn -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending dict (dict's) to allow for multidimensional dictionary
On 3/5/2011 12:05 PM, Paul Rubin wrote: Ravi writes: I can extend dictionary to allow for the my own special look-up tables. However now I want to be able to define multidimensional dictionary which supports look-up like this: d[1]['abc'][40] = 'dummy' Why do that anyway? You can use a tuple as a subscript: d[1,'abc',40] = 'dummy' Also, at some point, it's time to use a database. If you find yourself writing those "dictionaries" to files, or trying to look up everything with "abc" in the second subscript, a database is appropriate. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: 2to3 and maketrans
Martin v. Löwis wrote: Whether a GUI library is application programming or systems programming, I don't know. Neither do I, but it doesn't really matter. In my case the string is definitely text (although it will always be ascii) and therefore unicode is the right representation to use in 3.x. I just wondered whether there was a recommended idiom for using maketrans() on text in 2.7 that 2to3 would translate into str.maketrans(), but it seems not. Instead the solution seems to be to convert to unicode and use its translation method instead. I've since adopted a different solution, but I'll keep this in mind for the future. Thanks, everyone. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
BartC wrote: I got the impression the OP was talking about simply pinning down certain variables, so that a runtime name lookup (if that's in fact what Python does) was not necessary. A problem with this is that lexical name lookups are a relatively small proportion of the looking up that goes on in a typical Python program. Much more often you're looking up attributes of objects, which is much harder to turn into an indexed access, because the compiler has next to no knowledge of what type the object will be at run time. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Absolutely Insane Problem with Gmail
Hi; I have this code: #!/usr/bin/python import sys, os, string import cgitb; cgitb.enable() import cgi cwd = os.getcwd() dirs = string.split(cwd, '/') dirs = dirs[1:-1] backLevel = '/' + string.join(dirs, '/') sys.path.append(cwd) sys.path.append(backLevel) import string form = cgi.FieldStorage() // all the fields here subject = 'Order For Maya 2012' msg = 'First Name: %s\nLast Name: %s\nEmail Address: %s\nAddress2: %s, City: %s\nState: %s\nCountry: %s\nZip: %s\nPhone: %s\nFax: %s\nMessage: %s\n' % (firstNameText, lastNameText, emailText, addrText, addr2Te xt, cityText, stateText, countryText, zipText, faxText, messageText) ### LOOK AT THESE TWO LINES ourEmail = 'myemaila...@gmail.com' ourEmail = 'q...@xxx.com' def my_mail(): emailOne() emailTwo() def emailOne(): from simplemail import Email Email( from_address = ourEmail, to_address = emailText, subject = 'Thank you for your order!', message = msg ).send() def emailTwo(): from simplemail import Email Email( from simplemail import Email Email( # from_address = emailText, # to_address = ourEmail, from_address = ourEmail, to_address = emailText, subject = 'Order for Maya 2012', message = msg ).send() print '''Content-type: text/html ''' my_mail() print ''' ''' Now what's absolutely crazy about this is that if I use my online form and enter my gmail address I get the email confirmations. However, if I get rid of that garbage value for ourEmail and use the other one which is the _very_same_gmail_address I get nothing!! No email. Ditto if I uncomment those lines in emailTwo and delete the next two lines. What on earth could be doing this??? TIA, Beno -- http://mail.python.org/mailman/listinfo/python-list
One popular idea, for the christian louboutin salesfood family style. In t
One popular idea, for the christian louboutin salesfood family style. In this type of party, all of the food is put on the table, in large record transfer, rather than focusing on a waiter to all guest personal plate of food. Family style service cannot be frowsty than traditional plating dinners, and more elegant stage. Here are some ideas of how to arrange a family style wedding, your guests to love. Nokia N97 can support up to 48 GB of music, pictures, data file and video content, using 32 GB vehicle-mounted ability or 16 GB expansion can be accomplished by using micro – SD card. This means http://www.heelshoes08.com/";>christian louboutin shoes replay, equipment performance, including multimedia megapixel camera with a five – Karl Zeiss optical – might be used to the fullest and can be Shared use Ovi share services etc. Jonas Geust nokia deputy dean said, have Nseries N97 is “the most powerful, mobile computer more survival” or a may attract those that wish to leading technology curve. “N97 nokia mobile computers adjusts to the world around us and help people and keep in touch something really important.” Consumers want to restore health, and also may be christian louboutin designer of the other options, and was later released by the manufacturer. -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On 3/2/2011 9:27 PM, Steven D'Aprano wrote: On Wed, 02 Mar 2011 19:45:16 -0800, Yingjie Lan wrote: Hi everyone, Variables in Python are resolved dynamically at runtime, which comes at a performance cost. However, a lot of times we don't need that feature. Variables can be determined at compile time, which should boost up speed. [...] This is a very promising approach taken by a number of projects. It's worth having some syntax for constants. I'd suggest using "let": let PI = 3.1415926535897932384626433832795028841971693993751 I'd propose the following semantics: 1. "let" creates an object whose binding is unchangeable. This is effectively a constant, provided that the value is immutable. A compiler may treat such variables as constants for optimization purposes. 2. Assignment to a a variable created with "let" produces an error at compile time or run time. 3. Names bound with "let" have the same scope as any other name created in the same context. Function-local "let" variables are permitted. 4. It is an error to use "let" on a name explicitly made "global", because that would allow access to the variable before it was initialized. This is close to the semantics of "const" in C/C++, except that there's no notion of a const parameter. "let" allows the usual optimizations - constant folding, hoisting out of loops, compile time arithmetic, unboxing, etc. Ordinarily, Python compilers have to assume that any variable can be changed at any time from another thread, requiring worst-case code for everything. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: Absolutely Insane Problem with Gmail
>ourEmail = ' myemaila...@gmail.com' >ourEmail = ' q...@xxx.com' You redefine this twice. You also don't define a variable down lower. ># to_address = ourEmail, > from_address = ourEmail, > to_address = emailText, I could be wrong, but emailText isn't defined. Perhaps a better variable naming setup would help you some. so: in short, set up a to_address and from_address, populate those however you need to, then change the variable names. -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
> It's worth having some syntax for constants. I'd suggest >using "let": >let PI = 3.1415926535897932384626433832795028841971693993751 in to many languages, let is just a setter. why not just const pye = 3.14... -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On 06/03/2011 02:37, John Nagle wrote: On 3/2/2011 9:27 PM, Steven D'Aprano wrote: On Wed, 02 Mar 2011 19:45:16 -0800, Yingjie Lan wrote: Hi everyone, Variables in Python are resolved dynamically at runtime, which comes at a performance cost. However, a lot of times we don't need that feature. Variables can be determined at compile time, which should boost up speed. [...] This is a very promising approach taken by a number of projects. It's worth having some syntax for constants. I'd suggest using "let": let PI = 3.1415926535897932384626433832795028841971693993751 I'd propose the following semantics: 1. "let" creates an object whose binding is unchangeable. This is effectively a constant, provided that the value is immutable. A compiler may treat such variables as constants for optimization purposes. 2. Assignment to a a variable created with "let" produces an error at compile time or run time. 3. Names bound with "let" have the same scope as any other name created in the same context. Function-local "let" variables are permitted. 4. It is an error to use "let" on a name explicitly made "global", because that would allow access to the variable before it was initialized. This is close to the semantics of "const" in C/C++, except that there's no notion of a const parameter. "let" allows the usual optimizations - constant folding, hoisting out of loops, compile time arithmetic, unboxing, etc. Ordinarily, Python compilers have to assume that any variable can be changed at any time from another thread, requiring worst-case code for everything. Having a fixed binding could be useful elsewhere, for example, with function definitions: const PI = 3.1415926535897932384626433832795028841971693993751 const def squared(x): return x * x or: fixed PI = 3.1415926535897932384626433832795028841971693993751 fixed def squared(x): return x * x -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On 03/05/2011 10:23 PM, MRAB wrote: > Having a fixed binding could be useful elsewhere, for example, with > function definitions: > [..] > fixed PI = 3.1415926535897932384626433832795028841971693993751 > > fixed def squared(x): > return x * x This question spawns from my ignorance: When would a functions definition change? What is the difference between a dynamic function and a fixed function? -- Corey Richardson -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
A function object can get bound to a name, too: def foo(x): return x + 1 foo = lambda x: x - 1 assert foo(1) == 0 ~/santa On Sat, Mar 5, 2011 at 7:46 PM, Corey Richardson wrote: > On 03/05/2011 10:23 PM, MRAB wrote: > > Having a fixed binding could be useful elsewhere, for example, with > > function definitions: > > [..] > > fixed PI = 3.1415926535897932384626433832795028841971693993751 > > > > fixed def squared(x): > > return x * x > > This question spawns from my ignorance: When would a functions > definition change? What is the difference between a dynamic function and > a fixed function? > > -- > Corey Richardson > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
n00m wrote: > As for using color info... > my current strong opinion is: the colors must be forgot for good. > Paradoxically but "profound" elaboration and detailization can/will > spoil/undermine the whole thing. Just my current imo. Yeah. I guess including color info cubes the complexity of the answer. Might be too complicated to know what to do with an answer like that. Mel. -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On Sat, 2011-03-05 at 18:37 -0800, John Nagle wrote: > On 3/2/2011 9:27 PM, Steven D'Aprano wrote: > > On Wed, 02 Mar 2011 19:45:16 -0800, Yingjie Lan wrote: > > > >> Hi everyone, > >> > >> Variables in Python are resolved dynamically at runtime, which comes at > >> a performance cost. However, a lot of times we don't need that feature. > >> Variables can be determined at compile time, which should boost up > >> speed. > > [...] > > > > This is a very promising approach taken by a number of projects. > > It's worth having some syntax for constants. I'd suggest > using "let": > > let PI = 3.1415926535897932384626433832795028841971693993751 > > I'd propose the following semantics: > > 1. "let" creates an object whose binding is unchangeable. This > is effectively a constant, provided that the value is immutable. > A compiler may treat such variables as constants for optimization > purposes. > > 2. Assignment to a a variable created with "let" produces an error > at compile time or run time. > > 3. Names bound with "let" have the same scope as any other name > created in the same context. Function-local "let" variables > are permitted. > > 4. It is an error to use "let" on a name explicitly made "global", > because that would allow access to the variable before it was > initialized. > > This is close to the semantics of "const" in C/C++, except that > there's no notion of a const parameter. > > "let" allows the usual optimizations - constant folding, hoisting > out of loops, compile time arithmetic, unboxing, etc. Ordinarily, > Python compilers have to assume that any variable can be changed > at any time from another thread, requiring worst-case code for > everything. > > John Nagle I'm against constants, for the purpose of "programmers should be smart enough to not set a variable to another value that should be static", but if Python were to have constants I think it would be better to use something more descriptive than 'let'. Also, because the defined constant is static, I think it would be better to use 'is' instead of '='. Example: constant x is 5 -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On 3/5/2011 7:46 PM, Corey Richardson wrote: On 03/05/2011 10:23 PM, MRAB wrote: Having a fixed binding could be useful elsewhere, for example, with function definitions: [..] fixed PI = 3.1415926535897932384626433832795028841971693993751 fixed def squared(x): return x * x This question spawns from my ignorance: When would a functions definition change? What is the difference between a dynamic function and a fixed function? All functions in Python can be replaced dynamically. While they're running. From another thread. Really. Implementing this is either inefficient, with a lookup for every use (CPython) or really, really complicated, involving just-in-time compilers, invalidation, recompilation, and a backup interpreter for when things get ugly (PyPy). John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
Shouldn't this go to python-ideas? Anyway, I'm partial to "static". ~/santa On Sat, Mar 5, 2011 at 8:33 PM, Westley Martínez wrote: > On Sat, 2011-03-05 at 18:37 -0800, John Nagle wrote: > > On 3/2/2011 9:27 PM, Steven D'Aprano wrote: > > > On Wed, 02 Mar 2011 19:45:16 -0800, Yingjie Lan wrote: > > > > > >> Hi everyone, > > >> > > >> Variables in Python are resolved dynamically at runtime, which comes > at > > >> a performance cost. However, a lot of times we don't need that > feature. > > >> Variables can be determined at compile time, which should boost up > > >> speed. > > > [...] > > > > > > This is a very promising approach taken by a number of projects. > > > > It's worth having some syntax for constants. I'd suggest > > using "let": > > > > let PI = 3.1415926535897932384626433832795028841971693993751 > > > > I'd propose the following semantics: > > > > 1. "let" creates an object whose binding is unchangeable. This > > is effectively a constant, provided that the value is immutable. > > A compiler may treat such variables as constants for optimization > > purposes. > > > > 2. Assignment to a a variable created with "let" produces an error > > at compile time or run time. > > > > 3. Names bound with "let" have the same scope as any other name > > created in the same context. Function-local "let" variables > > are permitted. > > > > 4. It is an error to use "let" on a name explicitly made "global", > > because that would allow access to the variable before it was > > initialized. > > > > This is close to the semantics of "const" in C/C++, except that > > there's no notion of a const parameter. > > > > "let" allows the usual optimizations - constant folding, hoisting > > out of loops, compile time arithmetic, unboxing, etc. Ordinarily, > > Python compilers have to assume that any variable can be changed > > at any time from another thread, requiring worst-case code for > > everything. > > > > John Nagle > I'm against constants, for the purpose of "programmers should be smart > enough to not set a variable to another value that should be static", > but if Python were to have constants I think it would be better to use > something more descriptive than 'let'. Also, because the defined > constant is static, I think it would be better to use 'is' instead of > '='. Example: > > constant x is 5 > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
On Mar 6, 6:10 am, Mel wrote: > n00m wrote: > > As for using color info... > > my current strong opinion is: the colors must be forgot for good. > > Paradoxically but "profound" elaboration and detailization can/will > > spoil/undermine the whole thing. Just my current imo. > > Yeah. I guess including color info cubes the complexity of the answer. > Might be too complicated to know what to do with an answer like that. > > Mel. Uhmm, Mel. Totally agree with you. + I included "roses1.jpg" & "roses2.jpg" on purpose: the 1st one is a painting by Abbott Handerson Thayer, the 2nd is its copy by some obscure Russian painter. But it's of course a creative & revamped copy. In strict sense they are 2 different images (look at their colors etc) , on the other hand they are closely related to each other. Plus, we can't tell *in principle* what is original and what is copy what colors are "right/good" and what colors are "wrong/bad" -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On Mar 5, 7:46 pm, Corey Richardson wrote: > On 03/05/2011 10:23 PM, MRAB wrote: > > > Having a fixed binding could be useful elsewhere, for example, with > > function definitions: > > [..] > > fixed PI = 3.1415926535897932384626433832795028841971693993751 > > > fixed def squared(x): > > return x * x > > This question spawns from my ignorance: When would a functions > definition change? What is the difference between a dynamic function and > a fixed function? There's a bit of ambiguity here. We have to differentiate between "fixed binding" (which is what John Nagle and MRAB were talking about) and "immutable object" (which, apparently, is how you took it). I don't like speaking of "constants" in Python because it's not always clear which is meant, and IMO it's not a constant unless it's both. An immutable object like a number or tuple can't be modified, but the name refering to it can be rebound to a different object. a = (1,2,3) a.append(4) # illegal, can't modify a tuple a = (1,2,3,4) # but this is legal, can set a to a new tuple If a hypothetical fixed binding were added to Python, you wouldn't be able to rebind a after it was set: fixed a = (1,2,3) a = (1,2,3,4) # now illegal If you could define functions with fixed bindings like this, then a compiler that's a lot smarter than CPython's would be able to inline functions for potentially big speed increases. It can't do that now because the name of the function can always be rebound to something else. BTW, a function object is definitely mutable. def squared(x): return x*x squared.foo = 'bar' Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: ImSim: Image Similarity
http://www.nga.gov/search/index.shtm http://deyoung.famsf.org/search-collections etc Seems they all offer search only by keywords and this kind. What about to submit e.g. roses2.jpg (copy) and to find its original? Assume we don't know its author neither its title -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On Thu, 03 Mar 2011 08:52:16 -0800, Rafe Kettler wrote: >> Finally, Python 3 introduced type annotations, which are currently a >> feature looking for a reason. > > By type annotations, do you mean function annotations (see PEP 3107, > http://www.python.org/dev/peps/pep-3107/)? Or is this some other feature > that I'm unaware of? Sorry, yes, I meant function annotations. Of course you can use function annotations for more than just types. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: having both dynamic and static variables
On Thu, 03 Mar 2011 06:19:41 -0800, Westley Martínez wrote: > On Wed, 2011-03-02 at 19:45 -0800, Yingjie Lan wrote: >> Hi everyone, >> >> Variables in Python are resolved dynamically at runtime, which comes at >> a performance cost. However, a lot of times we don't need that feature. >> Variables can be determined at compile time, which should boost up >> speed. [...] > I once used this obscure language called "C"; it did kind of what you're > talking about. I'm told that there might be a couple of programming languages other than Python and C. Personally, I find that hard to believe. Why would the world need _three_ programming languages? *wink* -- Steven -- http://mail.python.org/mailman/listinfo/python-list
