🌐 Mailman 3 August 2004 - Python-list - python.org

Re: how to do proper subclassing?
by Larry Bates Aug. 3, 2004

Aug. 3, 2004

I think you want to have permfooation actually be a list. If you do then permfooation[1:3} will in fact return a list [3,4]. If the permutation is actually stored as: [0 1 2 3 4] [1 3 4 0 2] You can get them into lists with: f=open(inputfile) lines=f.readlines() f.close() l=0 for line in lines: if l % 2 == 0: continue # skip first lines l+=1 permfooation=[int(x) for x in line[1:-1].split()] print permfooation[1:3] Now you are probably going to want to wrap this into a class for easier use. HTH, Larry Bates Syscon, Inc. "Jonas Koelker" <jonaskoelker(a)yahoo.com> wrote in message news:mailman.1095.1091552353.5135.python-list@python.org... > Hello there. > > I'm new to this list (/me welcomes himself). > > anyways, I'm having doubts about how to subclass > properly. The big picture is that I want to handle > permutations. As we all know, two popular notation > forms exist: products of disjoint cycles ("(0 1 3)(2 > 4)") and 2*length matrices with the identity > permutation as the first line ([0 1 2 3 4] over [1 3 4 > 0 2]). I find the latter more appropriate, since it's > easy to store as a list (one can skip the first line, > assuming it's _always_ the identity). > > However, I want the permutation to act like a list, in > all those cases where I don't override the operations. > For example, assuming permfooation is the above > permutation [1 3 4 0 2], permfooation[1:3] should > return [3,4]. How is this done? Do I have to actually > implement a slice-mechanism in the permutation class? > > thanks, > > -- Jonas Kölker > > > > > > ___________________________________________________________ALL-NEW Yahoo! Messenger - all new features - even more fun! http://uk.messenger.yahoo.com

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Re: MYSQL and use of blobs
by Mark Hertel Aug. 3, 2004

Aug. 3, 2004

On Thu, 29 Jul 2004 08:48:28 -0500, Raaijmakers, Vincent (GE Infrastructure) <Vincent.Raaijmakers(a)ge.com> wrote: > It is the first time that I use blobs in mysql Please help me out . > here.... . > > Using MSSQLdb and python 2.3.4 I was surprised to see how my > information was stored in the blob. My goal is to store JPG > images in the blob. Well, it stores it but as a string of bytes: > 'x0dx0fxffxa3......' > > So, when reading back that information into my python environment, it > seems that I need to translate the value back to the original binary > format? > > Sniffed for an hour in the asciibin, binhex and other modules... > > Somebody with experience to help me out here? Is there something > fundamentally that I do wrong here? In storage, retreiving... > > Any help would be very appreciated. Vincent I didn't have to do anything more fancy than read the information from the database and write it as a binary file. SQL table: create table if not exists audioImage(id int auto_increment primary key, problemID int, realName varchar(250), shortName varchar(250), data longblob Storing the images/audio files: fileData = open(fileName, 'rb').read() fileData = zlib.compress(fileData,9) fileData = db.escape_string(fileData) query = "insert into audioImage(problemID, data, shortName) values(%d, '%s', '%s')" % (problemID, fileData, file) Retrieving the stored images or audio files: self.db.execute('select shortName,data from audioImage where id=%d' % int(id)) result = self.db.getAll() fileName = result[0][0] retResult = result[0][0] realData = zlib.decompress(result[0][1]) open(fileName,'wb').write(realData) This deposits the audio/image files in the current directory where the program picks them up and uses them. There wasn't anything special to do, other than retrieving and decompressing the data. --Mark Hertel

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Re_: Best way to run ipython inside of emacs shell?
by bulatov＠engr.orst.edu Aug. 3, 2004

Aug. 3, 2004

> Hi, > > Equis Uno wrote: > > > I use meta-x shell to start a shell and then once I see a shell > > prompt I enter the python command and I get a well-behaved python > > shell inside of emacs. > > > > I'm trying to figure out the best way to run ipython inside of emacs. I had the same problem. It has to do with ipython.el not finding the IPython executable. To fix it, open ipython.el, and replace line (when (executable-find "ipython") with (when (executable-find "ipython.bat") Next, add file ipython.bat to your path containing something like the following: C:\Python23\python.exe "C:\Program Files\IPython\IPython_shell.py" Unfortunately it doesn't seem to work right on windows. The prompts are missing so it's almost unusable. Yaroslav

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how to do proper subclassing?
by Jonas Koelker Aug. 3, 2004

Aug. 3, 2004

Hello there. I'm new to this list (/me welcomes himself). anyways, I'm having doubts about how to subclass properly. The big picture is that I want to handle permutations. As we all know, two popular notation forms exist: products of disjoint cycles ("(0 1 3)(2 4)") and 2*length matrices with the identity permutation as the first line ([0 1 2 3 4] over [1 3 4 0 2]). I find the latter more appropriate, since it's easy to store as a list (one can skip the first line, assuming it's _always_ the identity). However, I want the permutation to act like a list, in all those cases where I don't override the operations. For example, assuming permfooation is the above permutation [1 3 4 0 2], permfooation[1:3] should return [3,4]. How is this done? Do I have to actually implement a slice-mechanism in the permutation class? thanks, -- Jonas Kölker ___________________________________________________________ALL-NEW Yahoo! Messenger - all new features - even more fun! http://uk.messenger.yahoo.com

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The Great Computer Language Shootout (updated )
by igouy＠yahoo.com Aug. 3, 2004

Aug. 3, 2004

"The Great Computer Language Shootout" was mentioned a few months ago - note that the Shootout is active and welcoming contributions at: http://shootout.alioth.debian.org/

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Codecs for ISO 8859-11 (Thai) and 8859-16 (Romanian)
by peter_jacobi＠gmx.net Aug. 3, 2004

Aug. 3, 2004

I've seen from the 2.4alpha announcements, that the CJK codecs made it into this version. I'd like to ask whether (or how to) add the missing ISO 8859 codes: ISO 8859-11 (= TIS620) for Thai ISO 8859-16 for Romanian They are easily built from the Unicode mapping files like the other ISO 8859 codecs and it would just be nice, if they were included in the standard distribution. Peter

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Crypto.PublicKey.RSA.error: Plaintext too large
by Ajay Brar Aug. 3, 2004

Aug. 3, 2004

hi! I am getting an error - Crypto.PublicKey.RSA.error: Plaintext too large - when verifying the signature of a document. What i am doing is - the document and the signature are downloaded off the net, my verify script then connects to a server and obtains a public key. It then uses the public key to verify the signature. The whole thing works fine when i do the same thing in the interactive interpreter. Its only when i download the files and obtain the public key from the server and then verify, that i get the above error. any suggesstions...ideas??? cheers -- Ajay Brar CS Honours 2004 Smart Internet Technology Research Group http://www.it.usyd.edu.au/~abrar1

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Reasoning behind nested scope
by Andy Baker Aug. 3, 2004

Aug. 3, 2004

Hi there, I'm learning Python at the moment and trying to grok the thinking behind it's scoping and nesting rules. I was googling for nested functions and found this Guido quote: (http://www.python.org/search/hypermail/python-1993/0343.html) "This is because nested function definitions don't have access to the local variables of the surrounding block -- only to the globals of the containing module. This is done so that lookup of globals doesn't have to walk a chain of dictionaries -- as in C, there are just two nested scopes: locals and globals (and beyond this, built-ins). Therefore, nested functions have only a limited use. This was a deliberate decision, based upon experience with languages allowing arbitraries nesting such as Pascal and both Algols -- code with too many nested scopes is about as readable as code with too many GOTOs. And, of course, in Python, the "proper" way is to use an object-oriented programming style" This sounds reasonable to me although nested scope always struck me as more natural and intuitive ('Don't be surprising') I was wondering how the balance changed in favour of nested scope? What changed people's minds about 'readability' vs other factors? Are nested scopes still regarded as leading to spagetti code etc? (On a side note is there any way to call a nested function from outside the parent? I was kind of expecting nested functions to be addressable through dot notation like methods are but I can see why that wouldn't be quite right. This might be a better question for the tutor list...) Andy Baker

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PyGTK overload
by Egbert Bouwman Aug. 3, 2004

Aug. 3, 2004

As a newby to PyGTK I already have produced some gui's I like, but I have difficulties in finding out what method or other instrument I need for doing various things. I have not yet found the tutorial or otherwise that explains concepts like setting (relative) sizes, setting or manipulating focus, setting colors, etc. Also when I think I need a method with a specific word it its name, and I cannot find it, there are two (not necessarily exclusive) possibilities: - I have to go higher up the ancestry - I look for the wrong word Is there an other way than just going on and become familiar with it ? egbert -- Egbert Bouwman - Keizersgracht 197 II - 1016 DS Amsterdam - 020 6257991 ========================================================================

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Re: how do i do this - stream file
by Larry Bates Aug. 3, 2004

Aug. 3, 2004

Actually this can happen automatically. If the user's machine doesn't have a file association for the file extension of the file that they click on the browser automatically displays a open/save dialog for them when they click on the hyperlink. If they have an association defined on their machine, for the extension it launches the application when they click the hyperlink. On Windows this behavior is configurable. They can always right click on hyperlink and choose save instead. HTH, Larry Bates Syscon, Inc. "Ajay" <abra9823(a)mail.usyd.edu.au> wrote in message news:mailman.1083.1091521022.5135.python-list@python.org... > hi! > > How do i create and stream a file? > On a webpage i have a link to a file. Next to it i would like link, which, > when pressed, runs a script that calculates the signature of the file, > pickles the signature to a file and then gives a dialog box asking the > user whether they would like to save the file or open it. > > I have the script to do the signing and pickle the signature into a file, > but how do i allow the user to download it? > > thanks > > cheers > > -- > Ajay Brar, > > > > > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program.

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