🌐 Mailman 3 November 2001 - Tutor - python.org

Newbie Question: IDLE, is there a HOWTO use...
by Frank Peavy Dec. 1, 2001

Dec. 1, 2001

So far, I have used the IDLE to edit py's but it seems that there is more to it than that. Is there a HOWTO for the use of IDLE?

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the class struggle
by Rob McGee Dec. 1, 2001

Dec. 1, 2001

Hi all, I am a python 2.0 beginner. I'm trying to write a silly little program. Actually I *did* write it using a function definition, but I wanted to be object-oriented, so I'm trying to use a class instead. This isn't working out. {code} import random def myObject(name): variable = name anotherOne = anotherValue if name in someList: nextVar = this lastOne = that else: nextVar = random.randrange(10, 70) lastOne = random.randrange(5, 15) {/code} That works. I got a complete and working (although not very polished) program using a function like that. It's worthy of the Useless Python site, for sure. :) {code} import random class myObject(name): def __init__(self, name): variable = name anotherOne = anotherValue if name in someList: nextVar = this lastOne = that else: nextVar = random.randrange(10, 70) lastOne = random.randrange(5, 15) {/code} That doesn't work. "SyntaxError: invalid syntax" on the "if" (caret goes under the "f".) I tried adding "self." in front of the class instance variables just for fun. Same thing. I have read the tutorial and what I could find in the other docs about classes. I rented Ivan Van Laningham's "24 Hours" book at the local bookstore / coffee shop (I always buy a cup of coffee :) and thought I I was beginning to understand. I guess not. I tried commenting out the if/else lines and making a little function to test it out, and now everything after this accursed class definition is a SyntaxError. Is there something online with another description of using class definitions? Or perhaps can you fine folks point me in the right direction? BTW, except for classes I think I'm understanding things pretty well. I am able to make python do what I set out to do. Thank you, Rob - /dev/rob0

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Re: [Tutor] Newbie Question: IDLE, is there a HOWTO use...
by Kirby Urner Nov. 30, 2001

Nov. 30, 2001

At 02:10 PM 11/30/2001 -0800, Frank Peavy wrote: >So far, I have used the IDLE to edit py's but it seems that >there is more to it than that. >Is there a HOWTO for the use of IDLE? Have you used IDLE as a calculator? This is how the Python tutorial starts as I recall (the one that comes with it). >>> 1 + 1 2 >>> import.math >>> math.log10(100) 2.0 stuff like that. The next step is to keep some of your results stored in variables: >>> a = 1 + 1 >>> b = math.log10(100) >>> a + b 4.0 The next step is to write a function and run it: >>> def adder(a,b): return a + b >>> adder(3,4) 7 Now you're off and running. Explore string functions, goof off, and then, if you start getting functions you want to keep for next time, cut and paste 'em to an open text Window (IDLE's editor) and save 'em as a .py file. Group together functions that do similar things, so it makes sense to have 'em in the same file. Voila, you've written a Python module. Class dismissed. Kirby

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Linking Problems using VC++ 6.0
by Marcus Konermann Nov. 30, 2001

Nov. 30, 2001

Hi @ All ! I am working with SWIG and generated a C++ file to use it under python. I work with windows2000 and the VC++ 6.0 Compiler, but now there are linking problems, VC++ says: Temporäre Dateien und Ausgabedateien für "AG TEM - Win32 Debug" werden gelöscht. --------------------Konfiguration: AG TEM - Win32 Debug-------------------- SWIG !!! Kompilierung läuft... simanneal.cpp simanneal_wrap.cpp Linker-Vorgang läuft... Bibliothek Debug/AG TEM.lib und Objekt Debug/AG TEM.exp wird erstellt simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall variablelist::clean(void)" (?clean@variablelist@@QAEXXZ) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall variablelist::pt2xn(int)" (?pt2xn@variablelist@@QAEHH@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::copy(struct variable *)" (?copy@string@@QAEHPAUvariable@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::copy(struct variable *)" (?copy@string@@QAEHPAUvariable@@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct variable & __thiscall variable::operator=(struct variable &)" (??4variable@@QAEAAU0@AAU0@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl calculate(struct variable &,struct variablelist *,struct basisfile *,struct string *)" (?calculate@@YAHAAUvariable@@PAUvariablelist@@PAUbasisfile@@PAUstring@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl calculate(struct variable &,struct variablelist *,struct basisfile *,struct string *)" (?calculate@@YAHAAUvariable@@PAUvariablelist@@PAUbasisfile@@PAUstring@@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall evaluate::abort(struct variable &)" (?abort@evaluate@@QAEHAAUvariable@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall evaluate::abort(struct variable &)" (?abort@evaluate@@QAEHAAUvariable@@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall variable::~variable(void)" (??1variable@@QAE@XZ) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "void __cdecl strprint(struct string &,char *,char *)" (?strprint@@YAXAAUstring@@PAD1@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "void __cdecl strprint(struct string &,char *,char *)" (?strprint@@YAXAAUstring@@PAD1@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl calculate(struct variable &,struct basisfile *,struct string *)" (?calculate@@YAHAAUvariable@@PAUbasisfile@@PAUstring@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl calculate(struct variable &,struct basisfile *,struct string *)" (?calculate@@YAHAAUvariable@@PAUbasisfile@@PAUstring@@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall variable::init(double,int)" (?init@variable@@QAEXNH@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall variable::variable(void)" (??0variable@@QAE@XZ) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl read_double(double &,struct variable *)" (?read_double@@YAHAANPAUvariable@@@Z) simanneal.obj : error LNK2001: Nichtaufgeloestes externes Symbol "int __cdecl random_step(struct variable *,struct variable *)" (?random_step@@YAHPAUvariable@@0@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall evaluate::evaluate(void)" (??0evaluate@@QAE@XZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall evaluate::~evaluate(void)" (??1evaluate@@QAE@XZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall string::string(void)" (??0string@@QAE@XZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall string::string(int,char *)" (??0string@@QAE@HPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall string::string(char *,char *)" (??0string@@QAE@PAD0@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall string::string(struct string &,char *)" (??0string@@QAE@AAU0@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: __thiscall string::~string(void)" (??1string@@QAE@XZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall string::clean(void)" (?clean@string@@QAEXXZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::cat(struct string &)" (?cat@string@@QAEAAU1@AAU1@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::cat(char *)" (?cat@string@@QAEAAU1@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::copy(struct string &)" (?copy@string@@QAEAAU1@AAU1@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::copy(char *)" (?copy@string@@QAEAAU1@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::copy(double,long)" (?copy@string@@QAEHNJ@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::copy(int)" (?copy@string@@QAEHH@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall string::out(char * *)" (?out@string@@QAEXPAPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::ncopy(struct string &,int)" (?ncopy@string@@QAEAAU1@AAU1@H@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::ncopy(struct string &,int,int)" (?ncopy@string@@QAEAAU1@AAU1@HH@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::compose(struct string &,struct string &,char *)" (?compose@string@@QAEAAU1@AAU1@0PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::compose(struct string &,char *,char *)" (?compose@string@@QAEAAU1@AAU1@PAD1@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::compose(struct string &,double,char *)" (?compose@string@@QAEAAU1@AAU1@NPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct string & __thiscall string::compose(struct string &,int,char *)" (?compose@string@@QAEAAU1@AAU1@HPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::element(int)" (?element@string@@QAEHH@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::compare(struct string &)" (?compare@string@@QAEHAAU1@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::compare(char *)" (?compare@string@@QAEHPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_complement_span(char *,int)" (?string_complement_span@string@@QAEHPADH@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_complement_span(struct string &,int)" (?string_complement_span@string@@QAEHAAU1@H@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_complement_span(char *)" (?string_complement_span@string@@QAEHPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_span(struct string &,int)" (?string_span@string@@QAEHAAU1@H@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_span(char *,int)" (?string_span@string@@QAEHPADH@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_string(struct string &,char *)" (?string_string@string@@QAEHAAU1@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_string(struct string &,struct string &)" (?string_string@string@@QAEHAAU1@0@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_string(struct string &,struct string &,int)" (?string_string@string@@QAEHAAU1@0H@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::string_character(char)" (?string_character@string@@QAEHD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall string::string_pointer_break(struct string &,char *)" (?string_pointer_break@string@@QAEXAAU1@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: struct _iobuf * __thiscall string::fileopen(char *)" (?fileopen@string@@QAEPAU_iobuf@@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::fileread(struct string &)" (?fileread@string@@QAEHAAU1@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::filereadc(struct string &,char)" (?filereadc@string@@QAEHAAU1@D@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::filewrite(struct string &,char *)" (?filewrite@string@@QAEHAAU1@PAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::filewrite(struct _iobuf *)" (?filewrite@string@@QAEHPAU_iobuf@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: int __thiscall string::system_call(void)" (?system_call@string@@QAEHXZ) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "public: void __thiscall string::init(int,char *)" (?init@string@@QAEXHPAD@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "void __cdecl print(struct string &)" (?print@@YAXAAUstring@@@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "void __cdecl strprint(struct string &,int,char *,char *)" (?strprint@@YAXAAUstring@@HPAD1@Z) simanneal_wrap.obj : error LNK2001: Nichtaufgeloestes externes Symbol "void __cdecl strprint(struct string &,int,char,char *,char *)" (?strprint@@YAXAAUstring@@HDPAD1@Z) Debug/AG TEM.dll : fatal error LNK1120: 57 unaufgeloeste externe Verweise Fehler beim Ausführen von link.exe. AG TEM.dll - 63 Fehler, 0 Warnung(en) Have you got an idea ? Greetings Marcus

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destructor methods
by Timothy Wilson Nov. 30, 2001

Nov. 30, 2001

Hi everyone, I've started looking through the C++ code for that plagiarism program 'Copyfind'. I notice that the author has a destructor method to get rid of instances of his 'document' class. I don't recall any Python programs that use destructors (I'm not an accomplished object-oriented programmer). Does Python every use them? I understand that Python's garbage collection automatically takes care of that sort of thing. Is it possible that explicitly removing instances of a class improves performance in an application that uses a lot of RAM (like a plagiarism scanner, for instance :-)? -Tim -- Tim Wilson | Visit Sibley online: | Check out: Henry Sibley HS | http://www.isd197.org | http://www.zope.com W. St. Paul, MN | | http://slashdot.org wilson(a)visi.com | <dtml-var pithy_quote> | http://linux.com

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Python Development Standards..?
by Frank Peavy Nov. 30, 2001

Nov. 30, 2001

Lloyd wrote: >I suspect that you really want: >class myObject: > >Note that people usually capitalize their classes to help prevent this kind >of confusion. Lloyd mentions that "people usually.."; is there a resource that defines Python development standards?

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RE: [Tutor] linux
by Gouveia, John M W44 Nov. 30, 2001

Nov. 30, 2001

One other thing - years ago pre cd burner and cable connection there used to be a site called cheapbytes.com that would sell distro's for $1-$5. They basically just burned the free versions and mailed them to you. Don't know if they or anyone like them is still around but it came in handy when I'd want to try different distro's. Also, if you've got a burner and good connection linuxiso.org is a good iso 'portal'. John Gouveia CIGNA HealthCare IM&T IM Release 2 Decision Support Services <mailto:John.Gouveia2@Cigna.com> Confidential, unpublished property of CIGNA. Do not duplicate or distribute. Use and distribution limited solely to authorized personnel. © Copyright 2001 by CIGNA > -----Original Message----- > From: Jeff Jones [SMTP:thejoness3@home.com] > Sent: Friday, November 30, 2001 2:21 PM > To: tutor(a)python.org > Subject: Re: [Tutor] linux > > Thanks everyone for your help. I have found a LUG in my area and with > their > help hope to be on the 12 step program to windows freedom. > > "Hi, My name is Jeff, and I am a windows user...." > > > ----- Original Message ----- > From: "Rob McGee" <i812(a)iname.com> > To: <tutor(a)python.org> > Sent: Thursday, November 29, 2001 5:28 PM > Subject: Re: [Tutor] linux > > > > Jeff Jones wrote: > > > > Sorry about getting off topic here, but beginning to learn > programming > > > > through Python has peaked my interest in Linux. The only operating > system > > > > I have ever used has been windows, and I've been using it since the > DOS > > > > days (except for computer class in the 7th grade when we used apple > IIc). > > > > Not by choice but because that's what has always been there when I > turned > > > > the computer on. Getting to the point... Does anyone know of any > decent > > > > FAQ's etc. for windows users not yet switched to Linux. > Specifically, > > > > which version to use? Thanks in advance for any help. > > > > Different beginning users have different needs. Yes, Mandrake does a > > pretty good job of setting things up for you. It's very much like MS > > Windows in that regard! And also like MS Windows, you're not likely to > > learn as much about how things work behind the scenes. > > > > I started with Slackware, not quite 3 years ago. In that time I have > > attained some real competence as a GNU/Linux and UNIX sysadmin. I don't > > think I would have made it as far if I had started with something like > > Mandrake. (I know some who did, and they're not.) > > > > One thing for sure is that my skills are portable to any distro. I've > > seen the RedHat and Mandrake people talking about how to fix something, > > and their answers are all related to their GUI configuration tools. OTOH > > I would go to a configuration file and edit it. That works anywhere, not > > just Slackware. > > > > If you have a strong DOS background, you might appreciate Slackware. But > > if you just want to get up and running in a GUI ASAP, Mandrake and the > > other big commercial distros are good choices. I'd stay away from Corel > > (if it still exists) because it wasn't maintained, and steer clear of > > Caldera because of their per-seat licencing fees. > > > > Write me off-list if you're interested in Slackware. > > > > Rob - /dev/rob0 > > > > _______________________________________________ > > Tutor maillist - Tutor(a)python.org > > http://mail.python.org/mailman/listinfo/tutor > > > _______________________________________________ > Tutor maillist - Tutor(a)python.org > http://mail.python.org/mailman/listinfo/tutor ------------------------------------------------------------------------------ CONFIDENTIALITY NOTICE: If you have received this e-mail in error, please immediately notify the sender by e-mail at the address shown. This e-mail transmission may contain confidential information. This information is intended only for the use of the individual(s) or entity to whom it is intended even if addressed incorrectly. Please delete it from your files if you are not the intended recipient. Thank you for your compliance.© Copyright 2001 CIGNA ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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RE: [Tutor] linux
by Gouveia, John M W44 Nov. 30, 2001

Nov. 30, 2001

Jeff, If you're just starting with Linux, I'd recommend Mandrake-Linux.com. You can download it for free or and burn the iso's to cd or drop the $40 or so at a retailer(even WalMart). It has a nice GUI install and will probably detect most if not all of your hardware. A dedicated machine would be ideal but you can check out the how-to's on linuxdoc.org for dual booting with the version of Windows you already have. Have Fun. John Gouveia CIGNA HealthCare IM&T IM Release 2 Decision Support Services Phone: xxx.xxx-xxxx <mailto:John.Gouveia2@Cigna.com> Confidential, unpublished property of CIGNA. Do not duplicate or distribute. Use and distribution limited solely to authorized personnel. © Copyright 2001 by CIGNA > -----Original Message----- > From: Jeff Jones [SMTP:thejoness3@home.com] > Sent: Thursday, November 29, 2001 1:29 PM > To: tutor(a)python.org > Subject: [Tutor] linux > > Sorry about getting off topic here, but beginning to learn programming > through Python has peaked my interest in Linux. The only operating system > I have ever used has been windows, and I've been using it since the DOS > days (except for computer class in the 7th grade when we used apple IIc). > Not by choice but because that's what has always been there when I turned > the computer on. Getting to the point... Does anyone know of any decent > FAQ's etc. for windows users not yet switched to Linux. Specifically, > which version to use? Thanks in advance for any help. ------------------------------------------------------------------------------ CONFIDENTIALITY NOTICE: If you have received this e-mail in error, please immediately notify the sender by e-mail at the address shown. This e-mail transmission may contain confidential information. This information is intended only for the use of the individual(s) or entity to whom it is intended even if addressed incorrectly. Please delete it from your files if you are not the intended recipient. Thank you for your compliance.© Copyright 2001 CIGNA ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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Re: [Tutor] Variables by reference?
by Jeff Shannon Nov. 30, 2001

Nov. 30, 2001

> On Fri, 30 Nov 2001 10:27:15 -0500, > "Lee-Shanok, Bruce" <Bruce.Lee-Shanok(a)cognos.com> wrote: > > Is there any way to get python to return values by reference, like a C > pointer? Yes, there are ways to emulate this sort of behavior, but in Python, they're usually not the best way to approach the problem. What is it that you're trying to accomplish by returning a reference? Note that, in some ways, Python variables already act a lot like C pointers--every name is bound to (a reference to) some object. But the specific semantics are a bit different from C pointers (and usually much more sane). Jeff Shannon Technician/Programmer Credit International

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catching cheaters (cont.)
by Timothy Wilson Nov. 30, 2001

Nov. 30, 2001

Hi everyone, I located the Web page of the professor I mentioned in my initial message. He has a GPL'ed version of his 'Copyfind' software on his Web site at http://plagiarism.physics.virginia.edu/. The source is available (obviously for a GPD'ed program), but it's in C++. I think I can read it well enough to come up with some ideas of my own. Interestingly, he posts a list of improvements that could be made to the software and invites people to try to improve it. This could be a fun project to work on. And as they say in the free software world, most projects of this type get started because someone writes something to "scratch their own itch." -Tim -- Tim Wilson | Visit Sibley online: | Check out: Henry Sibley HS | http://www.isd197.org | http://www.zope.com W. St. Paul, MN | | http://slashdot.org wilson(a)visi.com | <dtml-var pithy_quote> | http://linux.com

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