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

module timeit and variable scope
by fortepianissimo＠gmail.com Aug. 2, 2004

Aug. 2, 2004

A couple questions about using timeit to record the CPU time consumed by an instance method: 1. What are the advantages of using timeit compared to using time.time() or time.clock()? (on Mac OS X) 2. How do I introduce a variable into the timeit.Timer? For example I have a class Foo: class Foo: def __init__ (self): # the following line didn't work because the scope is not # the calling function # self._timer = timeit.Timer(stmt='self.run(bar)') pass def someMethod (self, bar): print bar def run (self, bar): # call self.someMethod(bar) and record time using # self._timer pass and I want to record the CPU time consumed by someMethod in method run(), using the timer initialized in __init__(). The reason to set up the timer in __init__ is to avoid overhead of setting up the same timer time and time again in run(). Thank you.

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Strange timing data for list.pop()
by Roy Smith Aug. 2, 2004

Aug. 2, 2004

In the recent "transforming a list into a string" thread, we've been discussing the fact that list.pop() is O(1), but list.pop(0) is O(n). I decided to do a little timing experiment. To be sure, I did verify experimentally the expected result, but along the way, I came upon an interesting artifact that I'm at a loss to explain. I used the following to generate some timing numbers for pop() on various sized lists: import time for power in range (20): i = 2 ** power list = [1] * i t0 = time.time () list.pop () t1 = time.time () t = t1 - t0 print i, t I know wall clock time isn't a good way to time things, but it was a first cut before I dove into the manual and found os.times(). The interesting thing is the data that I got with the above code: 1 7.70092010498e-05 2 6.91413879395e-06 4 5.96046447754e-06 8 5.00679016113e-06 16 5.00679016113e-06 32 5.00679016113e-06 64 5.00679016113e-06 128 5.00679016113e-06 256 4.05311584473e-06 512 5.00679016113e-06 1024 5.00679016113e-06 2048 5.96046447754e-06 4096 9.05990600586e-06 8192 9.05990600586e-06 16384 9.05990600586e-06 32768 1.4066696167e-05 65536 2.31266021729e-05 131072 3.09944152832e-05 262144 3.60012054443e-05 524288 3.38554382324e-05 I plotted the data. http://www.panix.com/~roy/pop-times.png An interesting shaped curve! I haven't done any curve fitting, but by eye it looks something like k - log (1/n). The data is quite repeatable, too. Admitting that clock time is a silly thing to be measuring here, anybody have any clue what might be causing this behavior? This is on an otherwise idle 768 Mbyte PowerBook running OSX-10.3.4 and Python 2.3.4.

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Re: Trimming a string
by Double Dumbass on You Aug. 2, 2004

Aug. 2, 2004

Thanks for the tip. "Tim Williams" <listserver(a)tdw.net> wrote in message news:mailman.1055.1091461210.5135.python-list@python.org... > >I have a string that is 7 characters and represents file mode in UNIX/LINUX > from rpm: > > >0100755 > > >I don't care about the 0100 portion, I am only interested in the file > >permissions portion which is 755. How can I get three characters from the > >string starting at the right? ( -OR- strip 4 characters from the left? ) > > > > >>> str = "0100755" > >>> str1 = str[4:] > >>> print str1 > 755 > >>> str2 = str[-3:] > >>> print str2 > 755 > >>>

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Dr. Dobb's Python-URL! - weekly Python news and links (Aug 2)
by Peter Otten Aug. 2, 2004

Aug. 2, 2004

QOTW: "We can't really say much more about thread safety than this, we think the interpreter will survive. The rest is up to the programmer." - Donn Cave "Despite the seemingly endless necessity for doing so, it's actually not possible to reverse-engineer intended invariants from staring at thousands of lines of code (not in C, and not in Python code either)." - Tim Peters Marduk wants to use string formatting with an arbitrary iterable instead of a tuple. Hans Nowak posts a format function that fits the bill. http://groups.google.com/groups?selm=40FF1A61.9050408%40zephyrfalcon.org The release of IronPython 0.6, a Python implementation for .Net and Mono, spawns a broader discussion on the merits of .Net and the Common Language Runtime. http://groups.google.com/groups?threadm=278de0e.0407281353.27b6a457%40posti… http://www.ironpython.com Christopher T. King takes a closer look at Yaroslav Bulatov's attempt to benchmark various approaches to sum many floating point numbers. http://groups.google.com/groups?threadm=Pine.LNX.4.44.0408011847510.21160-1… Premshree Pillai writes an SMS-to-LiveJournal gateway in Python http://www.livejournal.com/users/premshree/33967.html How would you iterate over a list two consecutive items at a time? That's a the heart of jblazi's question, and it turns out that there are two ways to do it. http://groups.google.com/groups?threadm=pan.2004.07.31.12.27.23.547000%40ho… Patrick Rutledge has written an introduction on how to create games using pygame. http://www.linuxjournal.com/article.php?sid=7694 Is Python fully thread-safe? Jeff Epler is poking fun at the questioner, but Francois Pinard (sorry, no cedilla today) points the discussion into a more serious direction. http://groups.google.com/groups?threadm=mailman.775.1090684870.5135.python-… "Btw, thank you for those footnotes in Thinking in Java that encouraged me to try Python :-)" - Dan Bishop. Bruce Eckel, author of "Thinking in Java", asks for a test for string similarity. He receives various answers and a thank-you. http://groups.google.com/groups?threadm=mailman.958.1091195562.5135.python-… Dan Sugalski has lost the "Pie-thon" bet to Guido van Rossum that Python would run faster on Parrot, the virtual machine meant to power Perl 6. Images of Guido throwing the pie are finally available. http://www.onlamp.com/pub/wlg/5346 http://www.oreillynet.com/pub/a/oscon2004/friday/index.html ======================================================================== 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 Mygale is a news-gathering webcrawler that specializes in (new) World-Wide Web articles related to Python. http://www.awaretek.com/nowak/mygale.html While cosmetically similar, Mygale and the Daily Python-URL are utterly different in their technologies and generally in their results. comp.lang.python.announce announces new Python software. Be sure to scan this newsgroup weekly. http://groups.google.com/groups?oi=djq&as_ugroup=comp.lang.python.announce Brett Cannon continues the marvelous tradition established by Andrew Kuchling and Michael Hudson of intelligently summarizing action on the python-dev mailing list once every other week. http://www.python.org/dev/summary/ The Python Package Index catalogues packages. http://www.python.org/pypi/ The somewhat older Vaults of Parnassus ambitiously collects references to all sorts of Python resources. http://www.vex.net/~x/parnassus/ Much of Python's real work takes place on Special-Interest Group mailing lists http://www.python.org/sigs/ The Python Business Forum "further[s] the interests of companies that base their business on ... Python." http://www.python-in-business.org 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/donate.html Cetus collects Python hyperlinks. 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://aspn.activestate.com/ASPN/Cookbook/Python Among several Python-oriented RSS/RDF feeds available are http://www.python.org/channews.rdf http://bootleg-rss.g-blog.net/pythonware_com_daily.pcgi http://python.de/backend.php 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://python.sourceforge.net/peps/pep-0042.html The online Python Journal is posted at pythonjournal.cognizor.com. editor(a)pythonjournal.com and editor(a)pythonjournal.cognizor.com welcome submission of material that helps people's understanding of Python use, and offer Web presentation of your work. *Py: the Journal of the Python Language* http://www.pyzine.com Archive probing tricks of the trade: http://groups.google.com/groups?oi=djq&as_ugroup=comp.lang.python&num=100 http://groups.google.com/groups?meta=site%3Dgroups%26group%3Dcomp.lang.pyth… Previous - (U)se the (R)esource, (L)uke! - messages are listed here: http://www.ddj.com/topics/pythonurl/ http://purl.org/thecliff/python/url.html (dormant) or http://groups.google.com/groups?oi=djq&as_q=+Python-URL!&as_ugroup=comp.lan… Suggestions/corrections for next week's posting are always welcome. E-mail to <Python-URL(a)phaseit.net> should get through. To receive a new issue of this posting in e-mail each Monday morning (approximately), ask <claird(a)phaseit.net> to subscribe. Mention "Python-URL!". -- The Python-URL! Team-- Dr. Dobb's Journal (http://www.ddj.com) is pleased to participate in and sponsor the "Python-URL!" project.

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get attribute from a parent class
by Steve Aug. 2, 2004

Aug. 2, 2004

Hi, I have a nested class declaration such as: class A: def __init__(self): self.var = "A's variable" # end def class B: def __init__(self): self.var2 = "B's variable" # end def # end class B # end class A What I want to do is to be able to get class A's 'var' variable from the nested class B. For example, I want to be able to do something like: print "I can see you %s" % a.var but... I don't want to make 'var' a class variable. I want it to be an instance variable but still be viewable by the inner class B. Is this possible? Any suggestions? Thanks Steve

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Pygame - Only ONE Font found!?
by Askari Aug. 2, 2004

Aug. 2, 2004

Hi, It's the first time that I this... I install Python 2.3.4 after, I install PIL for Python 2.3 after, I install Pygame. But when I play a game (do by me; and work perfectly before my re- installation), first thinks when I see... the font is not "Times"... I modified my .py with add the this line : print "ListFont :", pygame.font.get_fonts() the resultat is: ListFont : ['netropaosdicon'] Where is the lots fonts on my system?!?! Askari My OS : WinXP (pro service pack 1)

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Re: Making a socket connection via a proxy server
by michael＠foord.net Aug. 2, 2004

Aug. 2, 2004

[snip..] > On another note: I assumed you wanted to transparently relay/rewrite HTTP > through the proxy. If you need to open some form of socket connection to the > proxy which is not HTTP, the proxy protocol supports the method CONNECT, > which will simply open up a socket connection which is relayed by the proxy. > But: This cannot be made transparent, except by some deeper magic in the > router. > > HTH! > > Heiko. Thanks for your help. It's only http that I'll be relayign and I only need it to be transparent to the user - I'm not using this for anonymity. I don't yet understand the detail of what you've said, but I am following hte resources you've suggested and now have enough to get to the next stage of my work. Thanks Fuzzyman http://www.voidspace.org.uk/atlantibots/pythonutils.html

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Sets Module Bug?
by Chris S. Aug. 2, 2004

Aug. 2, 2004

>>> from sets import * >>> Set((1,2,3)) Set([1, 2, 3]) >>> Set([1,2,3]) Set([1, 2, 3]) >>> Set(([1,2,3],[4,5,6])) Traceback (most recent call last): File "<input>", line 1, in ? File "sets.py", line 399, in __init__ self._update(iterable) File "sets.py", line 344, in _update data[element] = value TypeError: list objects are unhashable How can a Set using a tuple or list be ok, but not a tuple of lists?

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Re: Percentage matching of text
by usenet＠datahansa.com Aug. 2, 2004

Aug. 2, 2004

Hello Bruce, Bruce Eckel <BruceEckel(a)MailBlocks.com> wrote in message news:<mailman.958.1091195562.5135.python-list(a)python.org> > ... > What I'd like to do is find an algorithm that produces the results > of a text comparison as a percentage-match. > ... > Does anyone know of an algorithm or library that would do this? > Thanks in advance. > I suggest you to look at my software, GetReuse and its SDK: http://getreuse.com/ http://getreuse.com/sdk/ The formula for the calculation of the similarity is based on the scientific research. Any other "good" method of calculations should produce results that are equivalent in some terms to the GetReuse results. I have not wrote a paper yet; the formula is a improvement of the formula from http://www.cs.ucsb.edu/~mli/sid.ps . Unfortunately, I froze the project but the current code is tested and should work well. > Bruce Eckel > Bruce(a)EckelObjects.com Regards, Oleg

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Making a socket connection via a proxy server
by michael＠foord.net Aug. 2, 2004

Aug. 2, 2004

In a nutshell - the question I'm asking is, how do I make a socket conenction go via a proxy server ? All our internet traffic has to go through a proxy-server at location 'dav-serv:8080' and I need to make a socket connection through it. The reason (with code example) is as follows : I am hacking "Tiny HTTP Proxy" by SUZUKI Hisao to make an http proxy that modifies URLs. I haven't got very far - having started from zero knowledge of the 'hyper text transfer protocol'. It looks like the Tiny HTTP Proxy (using BaseHTTPServer as it's foundation) intercepts all requests to local addresses and then re-implements the request (whether it is CONNECT, GET, PUT or whatever). It logs everything that goes through it - I will simply edit it to amend the URL that is being asked for. It looks like the CONNECT and GET requests are just implemented using simple socket commands. (I say simple because there isn't a lot of code - I'm not familiar with the actual behaviour of sockets, but it doesn't look too complicated). What I need to do is rewrite the soc.connect(host_port) line in the following example so that it connects *via* my proxy-server. (which it doesn't by default). I think the current format of host_port is a tuple : (host_domain, port_no) Below is a summary of the GET command (I've inlined all the method calls - this example starts from the do_GET method) : soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM) soc.connect(host_port) soc.send("%s %s %s\r\n" % ( self.command, urlparse.urlunparse(('', '', path, params, query, '')), self.request_version)) self.headers['Connection'] = 'close' del self.headers['Proxy-Connection'] for key_val in self.headers.items(): soc.send("%s: %s\r\n" % key_val) soc.send("\r\n") max_idling=20 # this is really part of a self._read_write method iw = [self.connection, soc] ow = [] count = 0 while 1: count += 1 (ins, _, exs) = select.select(iw, ow, iw, 3) if exs: break if ins: for i in ins: if i is soc: out = self.connection else: out = soc data = i.recv(8192) if data: out.send(data) count = 0 else: print "\t" "idle", count if count == max_idling: break print "\t" "bye" soc.close() self.connection.close() Regards, Fuzzy http://www.voidspace.org.uk/atlantibots/pythonutils.html

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