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

Confusion About Classes
by flamesrock Jan. 2, 2005

Jan. 2, 2005

Hi, I've been playing like mad with all sorts of python modules..but I still can't seem to get my head around the proper use of a class and self. The question stems from this code I made(snippet): -------------------------------------------------------------------------------------- import httplib, ftplib, urllib2, exPyCrypto, score_configurations #custom class create_server: def __init__(self, domain, servername, master_ftpUSER, master_ftpPASS, score_ftpUSER, score_ftpPASS, httpport=None, ftpport=None): self.domain = domain if httpport is None: self.__httpport = '80' else: self.__httpport = httpport if ftpport is None: self.__ftpport = '21' else: self.__ftpport = ftpport if servername is None: self.__servername = 'SCORE-SERVER' else: self.__servername = servername self.master_ftpUSER = master_ftpUSER self.master_ftpPASS = master_ftpPASS self.score_ftpUSER = score_ftpUSER self.score_ftpPASS = score_ftpPASS self.parser = ConfigParser.ConfigParser() def createUniversalConfig(self, score_domain, score_servername, score_port): '''''' self.parser.add_section('score') self.parser.set('score', 'domain', self.score_domain) self.parser.set('score', 'server', self.score_servername) self.parser.set('score', 'server', self.score_port) ------------------------------------------------------------------------------------- The goal is to create a create_server object with the given parameters, and then call the method createUniversalConfig() without passing and parameters to it. So here are my questions: 1) in the function parameter heading <<def createUniversalConfig(self, score_domain, score_servername, score_port):>> do I need to include those parameters as written, like this-- <<def createUniversalConfig(self, self.score_domain, self.score_servername, self.score_port):>> or not pass any parameters at all? 2) Do I reference the body of the function like I originally wrote it: self.parser.add_section('score') self.parser.set('score', 'domain', self.score_domain) self.parser.set('score', 'server', self.score_servername) self.parser.set('score', 'server', self.score_port) or, like this self.parser.add_section('score') self.parser.set('score', 'domain', score_domain) self.parser.set('score', 'server', score_servername) self.parser.set('score', 'server', score_port) (if the goal is to call the method from the object without any parameters) 3) Can I create a configParser object and just call self.parser.set() inside the function without passing it as a parameter, or do I pass it as a parameter and call it as parser.set (without the 'self' statement.) Basically..I'm confused on the proper use of 'self' in this type of situation, even after going through all these different tutorials. Any ideas? -thanks in advance\

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Jython & IronPython Under Active Development?
by Haibao Tang Jan. 2, 2005

Jan. 2, 2005

This question may be a bit weird but I really want to know if these two hybrid projects are still active.

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Red Robin Jython & JDK classes
by Henri Sivonen Jan. 2, 2005

Jan. 2, 2005

I am trying to set up the Red Robin Jython Development Tools for Eclipse. It finds the Python libraries of Jython and my own jars. It does not find the JDK classes. If I try to add classes.jar from the JDK to the "Jython Class Path" of the project, the plug-in no longer finds even my own Java classes. How do I make the plug-in see the JDK classes? I am using Eclipse 3.0.1, Mac OS X 10.3.7, Java 1.4.2_05, Jython 2.1 and Red Robin Jython Development Tools 1.3.9. -- Henri Sivonen hsivonen(a)iki.fi http://iki.fi/hsivonen/

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Re: Securing a future for anonymous functions in Python
by Simo Melenius Jan. 1, 2005

Jan. 1, 2005

Ian Bicking <ianb(a)colorstudy.com> writes: > But I do think there's other ways to approach this. Function > expressions could get really out of hand, IMHO, and could easily lead > to twenty-line "expressions". That's aesthetically incompatible with > Python source, IMHO. You can already write unaesthetic hundred-line Python functions, if you want to. Python's syntax doesn't yet impose a restriction on the number of sequential statements :-) It sounds artificial to impose such restrictions on these hypothetical "inline blocks", even if by only allowing them to be plain expressions. IMHO, the most pythonic way to write an "inline-block" is by reusing existing keywords, using Python-like start-of-blocks and ending it by indentation rules: map (def x: if foo (x): return baz_1 (x) elif bar (x): return baz_2 (x) else: global hab hab.append (x) return baz_3 (hab), [1,2,3,4,5,6]) and for one-liners: map (def x: return x**2, [1,2,3,4,5,6]) As a side-effect, we also - got rid of the "lambda" keyword; - strenghtened the semantics of "def": a "def" already defines a function so it's only logical to use it to define anonymous functions, too; - unified the semantics: function is always a function, and functions return values by using "return". When learning Python, I learned the hard way that "lambda"s are expressions, not functions. I'd pay the burden of writing "return" more often in exchange for better consistency. my two cents, br, S

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Re: PyQT installation
by Steve Holden Jan. 1, 2005

Jan. 1, 2005

Phil Thompson wrote: > On Thursday 30 December 2004 4:13 pm, Steve Holden wrote: > >>Phil Thompson wrote: >> >>>On Thursday 30 December 2004 2:34 pm, Nanoscalesoft wrote: >>> >>>>hi phil... >>>>py-->2.4 >>>>pyqt-->3.3 >>> >>>I assume you mean PyQt-win-nc-msvc-3.13.exe >>> >>> >>>>qt-->2.3.0 >>> >>>I assume you mean the non-commercial edition. >>> >>>The binaries are built against Python 2.3.3 - Python 2.4 won't work. >>>Python 2.4 (and later) will never be supported by the non-commercial >>>edition because of the MSVC 6 vs 7 issue. >>> >>>Phil >> >>If that is a real *never* then Qt just fell behind in the "what's the >>best GUI platform" stakes. It'd be a shame to lose PyQT, but if there's >>no way to migrate it forwards it will atrophy and die. Have TrollTech >>said they will never issue MSVC 7 binaries? >> >>Is there no way to use the free Microsoft toolchain to compile, or do >>the language differences just make the whole deal too difficult (or is >>there some other show-stopper that my ignorance prevents me from seeing?). > > > You've completely misunderstood what I said. > And not for the first time, probably. Mea culpa. > I specifically said the non-commercial edition. This is a binary only version > based on Qt v2.3 and released in March 2001 - the first beta of Qt v4.0 has > just been released. The commercial and GPL versions of Qt is supplied in > source form and supports MSVC 6, 7, Borland, Cygwin and the Intel compiler. > PyQt supports all versions of Python since v1.5.2. > Well, OK, so I take it this means that TrollTech have announced they won't be producing an up to date non-commercial edition? I presume the non-commercial edition is for people who want to use Qt but don't want to pay licensing fees or open their source? Or is the GPL version only available on non-Windows platforms? Of all the GUI platforms I know about, Qt certainly has the murkiest licensing picture. > I think Qt is doing very well in the "best GUI platform" stakes if people > still want to use a 4 year old version in preference to up to date versions > of the alternatives. > I have no quibble with that - as I know, there are a lot of happy Qt users, and it has an interestingly different architecture. It would be even better if the licensing requirements were consistent across all platforms. and-if-wishes-were-horses-ly y'rs - steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119

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Complementary language?
by HackingYodel Jan. 1, 2005

Jan. 1, 2005

Hello all! I'm learning to program at home. I can't imagine a better language than Python for this. The ideal situation, for me, would be to study two languages at the same time. Probably sounds crazy, but it works out better for me. Being a newbie, I find almost all languages fascinating. C, D, Objective-C, Ocaml, C++, Lisp, how is a non-tech to choose? Does any single language do a better job in Python's weaker areas? Would anyone care to suggest one to supplement Python. That is, if you could only use Python and one other language, which would it be? Thank you for your time and help.

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Re: Securing a future for anonymous functions in Python
by David Bolen Jan. 1, 2005

Jan. 1, 2005

Ian Bicking <ianb(a)colorstudy.com> writes: > The one motivation I can see for function expressions is > callback-oriented programming, like: > > get_web_page(url, > when_retrieved={page | > give_page_to_other_object(munge_page(page))}) This is my primary use case for lambda's nowadays as well - typically just to provide a way to convert the input to a callback into a call to some other routine. I do a lot of Twisted stuff, whose deferred objects make heavy use of single parameter callbacks, and often you just want to call the next method in sequence, with some minor change (or to ignore) the last result. So for example, an asynchronous sequence of operations might be like: d = some_deferred_function() d.addCallback(lambda x: next_function()) d.addCallback(lambda blah: third_function(otherargs, blah)) d.addCallback(lambda x: last_function()) which to me is more readable (in terms of seeing the sequence of operations being performed in their proper order), then something like: def cb_next(x): return next_function() def cb_third(blah, otherargs): return third_function(otherargs, blah) def cb_last(x): return last_function() d = some_deferred_function() d.addCallback(cb_next) d.addCallback(cb_third, otherargs) d.addCallback(cb_next) which has an extra layer of naming (the callback functions), and requires more effort to follow the flow of what is really just a simple sequence of three functions being called. > I think this specific use case -- defining callbacks -- should be > addressed, rather than proposing a solution to something that isn't > necessary. (...) I'd be interested in this approach too, especially if it made it simpler to handle simple manipulation of callback arguments (e.g., since I often ignore a successful prior result in a callback in order to just move on to the next function in sequence). -- David

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Re: More baby squeaking - iterators in a class
by M.E.Farmer Jan. 1, 2005

Jan. 1, 2005

Terry Reedy wrote: >This is the wrong test for what I and some others thought you were asking. >The requirement for p to be an *iterable* and useable in code such as 'for >i in p' is that iter(p), not p itself, have a .next method, and iter(p) >will. Try ip=iter(p) followed by ip.next and ip.next() instead. Does that mean if you dont't call iter(() on your instance or have a next() method you can't do this: > class R3: > def __init__(self, d): > self.d=d > self.i=len(d) > def __iter__(self): > d,i = self.d, self.i > while i>0: > i-=1 > yield d[i] >>>> p=R3('eggs') >>>> for i in p: >>>> print i I am asking because I want to fully understand what makes an *iterator*. M.E.Farmer

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Parsing a search string
by Freddie Jan. 1, 2005

Jan. 1, 2005

Happy new year! Since I have run out of alcohol, I'll ask a question that I haven't really worked out an answer for yet. Is there an elegant way to turn something like: > moo cow "farmer john" -zug into: ['moo', 'cow', 'farmer john'], ['zug'] I'm trying to parse a search string so I can use it for SQL WHERE constraints, preferably without horrifying regular expressions. Uhh yeah. From 2005, Freddie

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Re: what is lambda used for in real code?
by Hans Nowak Jan. 1, 2005

Jan. 1, 2005

Adam DePrince wrote: > In sort, we must preserve the ability to create an anonymous function > simply because we can do so for every other object type, and functions > are not special enough to permit this special case. Your reasoning makes sense... lambda enables you to create a function as part of an expression, just like other types can be part of an expression. However, by that same reasoning, maybe classes aren't special enough either to warrant a special case. Where's the keyword to create an anonymous class? :-) -- Hans Nowak http://zephyrfalcon.org/

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