Actually, I have realized that using the bit vector XOR method by http://www.me.utexas.edu/~bard/IP/Handouts/cycles.pdf gives some possibility of doing so. However this method is still experimental and doesn't really have a definitive end to the algorithm (the base number of vectors can change).
Any ideas anyone? On Wed, Jul 22, 2009 at 9:12 PM, <python-list-requ...@python.org> wrote: > Send Python-list mailing list submissions to > python-l...@python.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://mail.python.org/mailman/listinfo/python-list > or, via email, send a message with subject or body 'help' to > python-list-requ...@python.org > > You can reach the person managing the list at > python-list-ow...@python.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Python-list digest..." > > Today's Topics: > > 1. Finding all cycles within an undirected graph (disappearedng) > 2. Re: Re: Changing the private variables content (Xavier Ho) > 3. Python-URL! - weekly Python news and links (Jul 22) > (Gabriel Genellina) > 4. Re: Multiple versions of python (Dave Angel) > 5. Re: Changing the private variables content (MRAB) > > > ---------- Forwarded message ---------- > From: disappearedng <disappeare...@gmail.com> > To: python-l...@python.org > Date: Wed, 22 Jul 2009 21:04:18 +0800 > Subject: Finding all cycles within an undirected graph > Hey everyone, > I am interested to find out all the cycles within an undirected graph. > I don't have a particular implementation of nodes and vertices yet, so > would someone kindly point out a good graph library for this ( I > looked at pygraph and python-graph, but not really satisfied ), in > addition to good algorithm for solving this issue. > > > > ---------- Forwarded message ---------- > From: Xavier Ho <cont...@xavierho.com> > To: python-l...@python.org > Date: Wed, 22 Jul 2009 23:06:22 +1000 > Subject: Re: Re: Changing the private variables content > Got it: > > exec('self.' + attr + '=\'' + val + '\'') > > That worked. I think it'll do what you want now ;) > > Ching-Yun "Xavier" Ho, Technical Artist > > Contact Information > Mobile: (+61) 04 3335 4748 > Skype ID: SpaXe85 > Email: cont...@xavierho.com > Website: http://xavierho.com/ > > > ---------- Forwarded message ---------- > From: "Gabriel Genellina" <python-...@phaseit.net> > To: python-l...@python.org > Date: Wed, 22 Jul 2009 12:48:25 +0000 (UTC) > Subject: Python-URL! - weekly Python news and links (Jul 22) > QOTW: "If programming is symbol manipulation, then you should remember that > the user interface is also symbol manipulation, and it is a MUCH harder > problem than databases, sorting, searching, and all the other problems you > learn about in academia. The user interface has to communicate over a rich > but noisy channel using multiple under-specified protocols to a couple of > pounds of meat which processes information using buggy heuristics evolved > over millions of years to find the ripe fruit, avoid being eaten, and have > sex. If you think getting XML was hard, that's *nothing* compared to user > interfaces. > > The fact that even bad UIs work at all is a credit to the heuristics, bugs > and all, in the meat." - Steven D'Aprano > http://groups.google.com/group/comp.lang.python/msg/8c65eacbd76e79cf > > > Invoke the same method over every object in a collection: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/8fd293a9b39c8733/ > > There is no 'xor' boolean operator, why? What should be its outcome? > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/16eec722310e75e8/ > > A thread-safe method to create unique identifiers (not necesarily > increasing integers): > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/dfe22a6446c057df/ > > Tim Chase tells us three ways to turn standard output into unbuffered mode: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/a65f71444bd4bb53/ > > How to receive data of unknown length using sockets: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/9e4a9f8b6e83320/ > > Override a method, but keeping the inherited docstring: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/1e4075ba10dcbdd9/ > > Limiting the execution time of a code fragment: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/734054de170e2904/ > > Sharing a big object between processes using the multiprocessing module: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/833d4988b7af6353/ > > Why aren't OrderedDicts [3.1] comparable using <, >, <=, >=? > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/c3c6f4fe7b6d487d/ > > So many ways to call a function - why is that? Beginners get confused: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/3fd57f5ee4850530/ > > The reasons to choose your favorite programming language (Python, I > presume!): > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/5d87008e328efcf9/ > > Tuples, lists, their differences and motivation: > > http://groups.google.com/group/comp.lang.python/browse_thread/thread/cb0cf56c52321ccc/ > > > ======================================================================== > Everything Python-related you want is probably one or two clicks away in > these pages: > > Python.org's Python Language Website is the traditional > center of Pythonia > http://www.python.org > Notice especially the master FAQ > http://www.python.org/doc/FAQ.html > > PythonWare complements the digest you're reading with the > marvelous daily python url > http://www.pythonware.com/daily > > Just beginning with Python? This page is a great place to start: > http://wiki.python.org/moin/BeginnersGuide/Programmers > > The Python Papers aims to publish "the efforts of Python enthusiasts": > http://pythonpapers.org/ > The Python Magazine is a technical monthly devoted to Python: > http://pythonmagazine.com > > Readers have recommended the "Planet" sites: > http://planetpython.org > http://planet.python.org > > comp.lang.python.announce announces new Python software. Be > sure to scan this newsgroup weekly. > http://groups.google.com/group/comp.lang.python.announce/topics > > Python411 indexes "podcasts ... to help people learn Python ..." > Updates appear more-than-weekly: > http://www.awaretek.com/python/index.html > > The Python Package Index catalogues packages. > http://www.python.org/pypi/ > > Much of Python's real work takes place on Special-Interest Group > mailing lists > http://www.python.org/sigs/ > > Python Success Stories--from air-traffic control to on-line > match-making--can inspire you or decision-makers to whom you're > subject with a vision of what the language makes practical. > http://www.pythonology.com/success > > The Python Software Foundation (PSF) has replaced the Python > Consortium as an independent nexus of activity. It has official > responsibility for Python's development and maintenance. > http://www.python.org/psf/ > Among the ways you can support PSF is with a donation. > http://www.python.org/psf/donations/ > > The Summary of Python Tracker Issues is an automatically generated > report summarizing new bugs, closed ones, and patch submissions. > > http://search.gmane.org/?author=status%40bugs.python.org&group=gmane.comp.python.devel&sort=date > > Although unmaintained since 2002, the Cetus collection of Python > hyperlinks retains a few gems. > http://www.cetus-links.org/oo_python.html > > Python FAQTS > http://python.faqts.com/ > > The Cookbook is a collaborative effort to capture useful and > interesting recipes. > http://code.activestate.com/recipes/langs/python/ > > Many Python conferences around the world are in preparation. > Watch this space for links to them. > > Among several Python-oriented RSS/RDF feeds available, see: > http://www.python.org/channews.rdf > For more, see: > http://www.syndic8.com/feedlist.php?ShowMatch=python&ShowStatus=all > The old Python "To-Do List" now lives principally in a > SourceForge reincarnation. > http://sourceforge.net/tracker/?atid=355470&group_id=5470&func=browse > http://www.python.org/dev/peps/pep-0042/ > > del.icio.us presents an intriguing approach to reference commentary. > It already aggregates quite a bit of Python intelligence. > http://del.icio.us/tag/python > > Enjoy the *Python Magazine*. > http://pymag.phparch.com/ > > *Py: the Journal of the Python Language* > http://www.pyzine.com > > Dr.Dobb's Portal is another source of Python news and articles: > http://www.ddj.com/TechSearch/searchResults.jhtml?queryText=python > and Python articles regularly appear at IBM DeveloperWorks: > > http://www.ibm.com/developerworks/search/searchResults.jsp?searchSite=dW&searchScope=dW&encodedQuery=python&rankprofile=8 > > Previous - (U)se the (R)esource, (L)uke! - messages are listed here: > http://search.gmane.org/?query=python+URL+weekly+news+links&group=gmane.comp.python.general&sort=date > http://groups.google.com/groups/search?q=Python-URL!+group%3Acomp.lang.python&start=0&scoring=d&; > http://lwn.net/Search/DoSearch?words=python-url&ctype3=yes&cat_25=yes > > There is *not* an RSS for "Python-URL!"--at least not yet. Arguments > for and against are occasionally entertained. > > > Suggestions/corrections for next week's posting are always welcome. > E-mail to <python-...@phaseit.net> should get through. > > To receive a new issue of this posting in e-mail each Monday morning > (approximately), ask <cla...@phaseit.net> to subscribe. Mention > "Python-URL!". Write to the same address to unsubscribe. > > > -- The Python-URL! Team-- > > Phaseit, Inc. (http://phaseit.net) is pleased to participate in and > sponsor the "Python-URL!" project. Watch this space for upcoming > news about posting archives. > > > > ---------- Forwarded message ---------- > From: Dave Angel <da...@ieee.org> > To: CCW <c.c.w...@gmail.com> > Date: Wed, 22 Jul 2009 09:11:26 -0400 > Subject: Re: Multiple versions of python > CCW wrote: >> >> On 21 July, 15:19, Dave Angel <da...@dejaviewphoto.com> wrote: >> >>> >>> ChrisW wrote: >>> >>>> >>>> Hi, >>>> I have installed 2 versions of python on my Windows XP computer - I >>>> originally had 3.0.1, but then found that the MySQL module only >>>> supported 2.*, so I've now installed that. I have found that if I >>>> change the Windows Environment Variable path, then I can change the >>>> version of python called when I type 'python' into a command line. >>>> However, I'd like to be able to choose which version I use. I know >>>> that if I change C:\Python26\python.exe to >>>> C:\Python26\python2.exe and C:\Python30\python.exe to C: >>>> \Python26\python3.exe, then typing 'python2' or 'python3' will invoke >>>> the correct interpreter. However, is it safe just to rename the >>>> executable files? Is there a more elegant way to achieve the same >>>> task? >>>> Thanks, >>>> Chris >>>> >>> >>> The elegant way is to have a batch directory on your PATH ( I use m:\t\bat >>> ) and put your *.bat files there. I do NOT put any python >>> installations on the PATH. >>> >>> For example, I have a batch file called: m:\t\bat\python26.bat >>> >>> c:\progfiles\python26\python.exe %* >>> >>> The %* syntax means pass all arguments through to the program. >>> >>> Once it all works, you can add an "@" in front of the c: in order to >>> suppress echoing the command. At that point, it'll look and work the >>> same way as what you did, but without modifying anything in the install >>> directory. (You may want python26.bat, pythonw26.bat, python31.bat >>> and pythonw31.bat) >>> >>> The other thing you may want to do in a batch file is to change the file >>> associations so that you can run the .py file directly, without typing >>> "python" or "pythonw" in front of it. >>> >>> The relevant Windows commands are: assoc and ftype And on a >>> related note, you may want to edit the PATHEXT environment variable, to >>> add .PY and .PYW >>> >> >> Thanks for this - this way made a bit more sense to me. I've now got >> C:\commands with the 4 .bat files in, and C:\commands in my path. It >> all seems to work :) I think I've missed the point of the @ though - >> it doesn't seem to make any difference.. >> >> I'm also a bit confused with the associations - since I've got python >> 2.6 and 3.1, surely the command I type (python26 or python31) is the >> only way to force a script to be run using a specific interpreter at >> runtime without having to change the .bat file every time I want to >> run a script using 3.1 instead of 2.6? >> >> > > The @ symbol was used in older versions of CMD and COMMAND to suppress > echoing of the command line. I think if you're using XP or later, it doesn't > matter. > > As for file associations, I don't know just what you already know about. > When you type data.doc at a command line, the system looks for the data > file, then if it's found, it looks up the program associated with that > extension. On my machine, that's a particular version of Word for Windows. > Similarly, if I type digest.py and I'm in the directory containing that > file, the system looks up my associations, and runs Python 2.6 on that file. > If I wanted it to run Python 3.1 on that file, I'd have to change the > associations, temporarily. > > So, first approximation, it's a way to avoid having to type PYTHON each time > I want to run a script, as long as I don't need any other arguments on the > (implied) command line. Further, the system will then look for digest.py > everywhere on the PATH, so I don't even have to be in the same directory. > And that means I can be in the data directory that digest.py is going to work > on. Effectively, it raises digest.py to feeling like an executable, for most > purposes. In fact, I put all my scripts in a directory, along with other > simple executables. I use m:\t\bin for that purpose. > > These associations (to .py and .pyw) are established by the installer program > for Python. But when you had multiple installs, you could choose whether the > second one installed overrides the first. My point is that if you need to > change them back and forth, you could use assoc and ftype to do it. > > On my system: > > M:\LabOrders>assoc .py > .py=Python.File > > M:\LabOrders>ftype Python.File > Python.File="C:\PROGFI~1\ACTIVE~1\python.exe" "%1" %* > > M:\LabOrders> > > > So my .py files are associated with the 2.6.2 version of ActivePython > installation. Note the similarity of the ftype to your python26.bat file? > > One more little trick is that I could just type digest instead of > digest.py, if I have added the .py and .pyw extensions to my PATHEXT > environment variable. So my PATHEXT looks like: > PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.PY;.PYW > > > > Note that the association changes made by assoc and ftype are global. They > apply to all cmd.exe windows, even those already running, and they survive a > reboot. But when you set environment variables like PATHEXT, you can choose > to do it in a single window (with SET), or globally (using control-panel). > > If I found myself switching often, I'd make separate ftype entries for each > interpreter, something like > Python.File26="C:\PROGFI~1\ACTIVE~1\python.exe" "%1" %* > Python.File31="C:\PROGFI~1\..... > and just change assoc .py to point at the one I needed today. > > As it is, I'm content leaving the associations pointing at 2.6, and > explicitly entering PYTHON31 in front of any script name I want to run on > that interpreter. > > DaveA > > > > > ---------- Forwarded message ---------- > From: MRAB <pyt...@mrabarnett.plus.com> > To: python-l...@python.org > Date: Wed, 22 Jul 2009 14:12:18 +0100 > Subject: Re: Changing the private variables content > Ryniek90 wrote: >>> >>> ------------------------------------------------------------------------ >>> >>> Temat: >>> Re: Changing the private variables content >>> Od: >>> Gary Herron <gher...@islandtraining.com> >>> Data: >>> Tue, 21 Jul 2009 14:14:44 -0700 >>> Do: >>> Ryniek90 <rynie...@gmail.com> >>> >>> Do: >>> Ryniek90 <rynie...@gmail.com> >>> Kopia: >>> python-list@python.org >>> >>> >>> Ryniek90 wrote: >>>> >>>> Hi. >>>> I'm writing some class, and decided to use inside private method and some >>>> private variables. While with method i haven't got any problem's with >>>> variables i have. >>>> Maybe some example. >>>> A class with private method and private variable: >>>> >>>> " >>>> >>> class Secret(object): >>>> # >>>> def __init__(self): >>>> self._number = 1 >>>> # >>>> def _secret(self): >>>> print self._number >>>> def showit(self): >>>> print "Secret number is:\n" >>>> self._secret() >>>> >>>> >>> sec = Secret() >>>> >>> sec.showit() >>>> Secret number is: >>>> >>>> 1 >>>> >>> sec._number >>>> 1 >>>> >>> sec._number = 2 >>>> >>> sec._number >>>> 2 >>>> >>> sec._number += 3 >>>> >>> sec._number >>>> 5 >>>> >>> >>>> " >>>> >>>> As You can see, i made class with private method and private variable >>>> inside __init__ constructor. I've changed also the variable value, but >>>> outside class. >>>> I've got problem with changing some variable value _inside__my_ class, >>>> which i'm writing. >>> >>> Not sure this is what you are asking, but a method (which is how I >>> interpret "_inside__my_ class") changes the value by normal assignment like >>> this: >>> >>> class Secret(object): >>> ... >>> def SetNumber(self,value): >>> self._number = value >>> >>> Is that what you were asking? >>> >>> >>> Gary Herron >>> >>> >>> >>>> I've searched over google, some tuts with topics about operations on >>>> private variables, but didn't found anything - only how to make them, but >>>> no how to assign new objects/override them with new content (and other >>>> advanced and helpful options). >>>> >>>> If someone could help me, it would be great. >>>> >>>> Thanks. >>> >>> >> >> >> Thanks for hint, but looks like i can't do what i want. >> >> Maybe i show You my class: >> >> " >> >> class ModPrint(object): >> u""" >> This will be the doc. >> """ >> def __init__(self): >> #Assign the Python installation directory - sys.exec_prefix - to >> variable >> self._default_search_path=sys.exec_prefix >> self._chosen_module = '' >> self._user_search_path = '' >> self._this_module = '' >> def _SetVar(self, attr, val): >> self.attr = val def _search_for_module(self, *args): >> """Private method which walks through default Python >> installation directories, and search for prefered module.""" >> #walking thru all directories available in path >> '_user_search_path' >> for root, dirs, files in os.walk(self._user_search_path): >> for f in files: >> #if found file 'f' is THAT module, >> #full path to THAT file is assigned to variable >> if f == ("%s.py" % self._chosen_module): >> self._SetVar(self._this_module, os.path.join(root, f)) >> def print_module(self, >> _chosen_module='', _user_search_path='', >> _default_search_path=sys.exec_prefix,): >> """Reads module chosen by user, and returns full content of this >> module, as it is.""" >> #if custom search path hasn't been assigned, >> #default path is being assigned as custom path >> if self._user_search_path == '': >> self._user_search_path = self._default_search_path >> #using private method '_search_for_module' with 'self.' >> preffix >> #to search for prefered module >> self._search_for_module(_chosen_module, _user_search_path) >> #opening prefered module with read-only binary mode >> #and assigning it to 'module_open' variable >> module_open = open(self._this_module, 'rb') >> #reading this file and assigning it to variable >> module_text = module_open.read() >> #closing read file; the read content is still available >> #it's stored in variable 'module_text' >> module_open.close() >> #returning the read content >> return module_text >> >> " >> >> When i use this class in Python IDLE, i've got this error: >> " >> >>> mod = ModPrint() >> >>> import socket >> >>> mod.print_module('socket') >> >> Traceback (most recent call last): >> File "<pyshell#60>", line 1, in <module> >> mod.print_module('socket') >> File "<pyshell#57>", line 48, in print_module >> module_open = open(self._this_module, 'rb') >> IOError: [Errno 2] No such file or directory: '' >> >>> >> " >> >> As You can see, i can't assign the new value "os.path.join(root, f)" to the >> 'self._this_module variable'. >> So for sure i've made some mistake in method: >> >> " >> def _SetVar(self, attr, val): >> self.attr = val " >> When i've changed private variables to normal, stored in class (in __init__ >> method), it was the same situation - i couldn't change this variable value. >> >> " >> >>> mod = ModPrint() >> >>> mod.print_module('os') >> >> Traceback (most recent call last): >> File "<pyshell#72>", line 1, in <module> >> mod.print_module('os') >> File "<pyshell#64>", line 48, in print_module >> module_open = open(self.this_module, 'rb') >> IOError: [Errno 2] No such file or directory: '' >> >>> >> " >> >> Thanks i someone could help me, give some hint. > > What is the point of the _SetVar method? > > Instead of: > > self._SetVar(self._this_module, os.path.join(root, f)) > > just do: > > self._this_module = os.path.join(root, f) > > (unless I'm misunderstanding what you're trying to do!) > > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
