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

Re: python connection to mssql from windows box
by Graeme Matthew Oct. 4, 2004

Oct. 4, 2004

look at the ODBTP page I think ther eis a python wrapper for it :-) "Josh Close" <narshe(a)gmail.com> wrote in message news:mailman.4134.1096552901.5135.python-list@python.org... > On Thu, 30 Sep 2004 09:09:05 +0100, Tim Golden > <tim.golden(a)viacom-outdoor.co.uk> wrote: >> I think you're asking for this: >> >> http://www.object-craft.com.au/projects/mssql/ >> >> (which, by the way, is the first non-mailing-list result >> Google gives for python mssql) >> >> TJG > > Google? What's that? > > I use the Sybase module by object-craft for linux/python connections > to mssql, and I refuse to use the mssql module due to these things > listed on the main mssql page. > > There are a few things that do not work - the work still has not been > done. > > * Almost no testing has been performed - if you use the module you > will be a pioneer. > * You cannot send parameters to Cursor.execute() - for the moment > you must format an SQL expression with the parameters inline. > * On Windows the Cursor.callproc() method does not work. Some guru > will have to figure out what is going wrong (i.e. not me). You can > achieve the same result by simply using Cursor.execute(). For example: > > c = db.cursor() > c.execute('sp_help titles') > > * The state machine for the Cursor class is quite hokey. It > returns COMPUTE rows in their own result set. At some stage this will > be cleaned up. > * The Connection.commit() and Connection.rollback() methods have > not been implemented. > > > So basically it *kind of* works, but not well. I'm talking about > native windows module that uses the client tools api. Maybe ADO will > be the best thing for me. I've seen some problems with that too > though...... man I hate mssql. > > -Josh

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[OT-Slightly] Sun Micro engineers bashing Java, and mentioning Python even Eiffel
by Adonis Oct. 4, 2004

Oct. 4, 2004

I do not know if this was ever posted on here but check this Sun Micro internal memo out: http://www.internalmemos.com/memos/memodetails.php?memo_id=1321 Here is the paragraph where it is mentioned: A study performed by an outside team appears to indicate a rough parity in performance between Java and a common implementation of another OO language called Python (see IEEE Computing, October 2000, "An Empirical Comparison of Seven Programming Languages" by Lutz Prechelt of the University of Karlsruhe). Both platforms are Object Oriented, support web applications, serialization, internet connections and native interfaces. The key difference is that Python is a scripting language. This means there is no compilation to byte code so the Python runtime environment has to do two things in addition to what the Java runtime environment does. It has to perform syntax checks and it must parse the ascii text provided by the programmer. Both of those tasks are performed at compile time by Java and so that capability does not have to be in the JRE. Given this data, it appears that the JRE can actually be simpler than the Python RE since Java does at least some of this work at compile time. The example above of "Hello World" is a good method for getting an idea of the minimum support code required at runtime. This support code includes garbage collector, byte code interpreter, exception processor and the like. Hello World written in Java2 requires 9M for this most basic support infrastructure. By comparison, this is slightly larger than automountd on Solaris8. The Python runtime required to execute Hello World is roughly 1.6M. Adonis

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ANN: cfgparse-0.1 - An alternative to ConfigParser
by Paramjit Oberoi Oct. 4, 2004

Oct. 4, 2004

http://www.cs.wisc.edu/~param/software/cfgparse/ cfgparse is a Python module that provides mechanisms for managing configuration information. It is backward compatible with ConfigParser, in addition to having the following features: * Preserves structure of INI files: Order of sections & options, indentation (to some extent), comments, and blank lines are preserved when data is updated. * More convenient than ConfigParser: Values can be accessed using dotted notation, or using container syntax (cfg[key]). * Backward compatibility: Backward compatible implementations of ConfigParser, RawConfigParser, and SafeConfigParser are included that are API-compatible with the Python standard library. They pass all the unit tests in Python-2.3.4. * Extensible: It is possible to add other configuration formats, and to convert between different formats (as long as the data models are compatible). Bug reports/suggestions/comments welcome. Contact: Paramjit Oberoi <param(a)cs.wisc.edu>

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Re: Dynamically Generating a Graph in Python
by HansWL＠msn.com Oct. 4, 2004

Oct. 4, 2004

John Hunter <jdhunter(a)ace.bsd.uchicago.edu> wrote > gdmodule is really more of a low level drawing program than a graphing > module. Of course you can draw graphs with it, as you can with any > drawing program, but it's a lot easier to make scientific graphs (the > OP's interest) with a program designed for that purpose. matplotlib > has a gdmodule backend. > > http://matplotlib.sourceforge.net/backends.html#GD > > JDH I tried matplotlib 0.63 with Python 2.3.4 on an old Win98 machine (500 MHz, 128 MB RAM) and found that I had to wait for at least 35 seconds before even the simplest demo plot appeared. Is this expected? The plots looked great, I just hope they appeared faster.

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Re: metaclass and customization with parameters
by aleaxit＠yahoo.com Oct. 4, 2004

Oct. 4, 2004

Carlos Ribeiro <carribeiro(a)gmail.com> wrote: ... Mostly interesting comments, snipped but hopefully useful to clear up some confusions from readers, but one I need to comment on...: > languages. That happens because def's are not executed at this time - > def's are only compiled. But any code inside a class definition that Each def statement IS indeed executed; I think what you mean to say is that a def statement does not execute the body of the function it's defining, it just stashes that body away (in a compiled form) for future execution (each time that function is called). Alex

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Re: python vs c#
by Tim Roberts Oct. 3, 2004

Oct. 3, 2004

Steve Holden <steve(a)holdenweb.com> wrote: >> >> IIRC from back when I was in school (long time ago), both forms are correct. >> At least in Dutch. Strictly spoken it should be "a few is enough" or "a >> number of people has died". > >Well that's Dutch for you. In English (as opposed to American, where >pretty much anything goes) "A number of people *have* died" is correct, >because the people died, not the number. I was going to object to this statement. I went to my good friend "Google" to look up some references but "a number of" is very common and thus difficult to search for. However, on the web site for "The American Heritage Book of English Usage," I was reading the page on indefinite pronouns, looking for vindication, when I came across this sentence: A number of usage problems involving personal pronouns are questions of which case to use in a given situation. They don't explicitly give a rule, but it's clear that whoever wrote this sentence (presumably a stern-faced librarian) agrees with you. -- - Tim Roberts, timr(a)probo.com Providenza & Boekelheide, Inc.

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test_tcl and Python 2.4a3
by E. Daniel Oct. 3, 2004

Oct. 3, 2004

After I ran the regrtest suite on Python 2.4a3 several times to make sure, I noticed that when test_tcl's turn comes up and it is run that instead of 2 threads appearing in Wintop.exe (a process viewer for Windows 98) for Python that five threads then appear and these threads (extra or otherwise) continue even after test_tcl is finished and test_tempfile and those after it are picked up and run. This behavior does not seem to happen in Python 2.3.4, where test_tcl is not found in the regrtest suite BTW. Trying to narrow the problem down, I ran test_tcl on its own, and sure enough Wintop showed three more threads for Python 2.4a3, which itself seems to hang, even after the Tkinter window the test shows is closed. But coming back to running test_tcl within the regrtest suite, and most often than not when the regrtest reaches test_threaded_import I get the message that the test crashed because it could not create threads. Does all this seem like there is a bug somewhere, or is my Python/Tcl/Tkinter copy bad? Thank you --------------------------------- Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages!

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Learn French in the Alps.
by John Cuteaux Oct. 3, 2004

Oct. 3, 2004

To learn French in France, I found this great school, located both in Annecy and Chambéry, in the heart of the Alps. Given the number of activities and the surroundings I thought I would share this ressource with others. http://www.ifalpes.com Let me know if you have any good education portal ressources. Thanks.

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beta test release - catchmail for Python - new open source utility -
by Andrew Stuart Oct. 3, 2004

Oct. 3, 2004

Hello all, I am releasing a utility called catchmail to open source under a BSD style license. Here is the catchmail homepage: http://www.users.bigpond.net.au/mysite/catchmail.htm Catchmail is a Python utility that writes emails into a Postgres database. Catchmail's SQL schema is based on an extended version of the Yukatan data model (a SQL schema for relational storage of email RFC822 messages). catchmail needs real world testing and feedback however before it can progress beyond beta release. It's not quite ready for release however - it needs more people to try to use it and check it out before full scale public release. If anyone has the time or the inclination I would value a code review and advice being given as to how to do things differently or better. I'm no great Python programmer so any volunteers who might be interested in helping to enhance and help support catchmail would be much appreciated. I have set up a newsgroup at http://groups-beta.google.com/catchmail There is also a final known problem that I would value advice on. Everything seems to be working fine except one thing - unicode If I create the database using this command, everything seems to run fine - I can import 4000 emails if I create the Postgres data with this command: createdb -U postgres catchmail; If I create the Postgres database using this command, postgres starts to come back with unicode errors when I do the import createdb --encoding=UNICODE -U postgres test The import process starts to fail on lots of messages with this error: Database error: ERROR: invalid byte sequence for encoding "UNICODE": 0xe92062 The objective is to have the database in Unicode so I suppose its quite an important problem to resolve. It looks to me like some sort of encoding/decoding requirement but although I had a good look I couldn't sort it out. I'm afraid I don't much understand how unicode is meant to be used in this sort of application - if you can throw any light on it for me it would be appreciated. How SHOULD unicode be implemented for a utility such as this? I'd like catchmail to be as flexible as possible and to lose as little data as possible through things like character set conversions. I found some references to client encoding and multibyte in the postgres docs here - but maybe it should be fixed in the Python code? SET CLIENT_ENCODING TO 'value'; http://jamesthornton.com/postgres/7.3/postgres/multibyte.html http://www.postgresql.org/docs/7.4/static/multibyte.html#MULTIBYTE-TRANSLAT… The latest version of catchmail is the one found on the website at http://www.users.bigpond.net.au/mysite/catchmail.htm Any feedback on catchmail or your experience with catchmail valued. Thanks to the great work of Mark Hammond and Jukka Zitting! Andrew Stuart a n d r e w . s t u a r t @ x s e . c o m . a u

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Re: Python in Process Control?
by Neil Benn Oct. 3, 2004

Oct. 3, 2004

Hello, Comments beneath : Peter L Hansen <peter(a)engcorp.com> wrote in message news:<AcadnZxtQPvH9cDcRVn-sg(a)powergate.ca>... <snip> > I meant to mention, but only barely implied, that the source is > actually available, on Engenuity's project page. It was a > Cavro RSP9000 robot. Oh, how long ago was that as far as I know that model was discontinued a long time ago. I skipped a few of them myself (there's nothing wrong with the machine - it's just an old model and not up to today's standards). <snip> > I use the terms "industrial control" and "automation" rather > interchangeably, along with "laboratory robotics" and other > terms. It's all the same thing, regardless of the end user, > except when regulatory issues get involved (aeronautics, FDA > approvals, etc). Hmm, not sure about that - you need to look at the process it is being used in and the cost of downtime. In addition you also have to consider the end users and the cost of a lost unit - this is why people talk about industrial automation in a lab setting with no concept of what they mean, in the field of laboratory automaiton industrial automation is typically used as a marketing slogan!! In life science unit cost is an awkward indicator as it is very difficult to put a cost on a lost unit - it could be nothing, it could be billions!! If you are interested in this field then there is an active mailing list on laboratory automation, you can access it trhough the american link of www.lab-robotics.org or the European link www.elrig.org. > > > IMHO, I think that Python is not a suitable piece of software for > > industrial control as it has poor support for bytes (a string shouldn't > > be used to store bytes!) and also bit twiddling is difficult (people who > > ask about his on the Python newsgroup are usually shouted at). > > Well, let me see how to answer this politely. :-) What you *think* > and what is reality are not necessarily the same thing. ;-) No, > the more polite answer is really that this is an area where perhaps > it's more a matter of opinion than anything else, and mine differs > from yours. Yep, that's why I put IMHO - don't get me wrong, I have used python for control and it has good sides and bad sides - like everything in life! I j > > Python certainly has *excellent* ("perfect"?) support for manipulating > bytes, and if you consider that a string is not a string, but is > actually a sequence of bytes, then other than being misnamed for > this application area, a string provides great support for bytes... > certainly *in practice* it works wonderfully, and I guess as someone > who has used Python very successfully for industrial control I'm > somewhat qualified to say so. I've also got python running controlling a bunch of kit - as for byte support, sorry but a byte array should not have the ability to be changed into upper case unless it represents characters - which bytes patently do not. I know it works in python but it's an incorrect metaphor. In the same way that a string is not a bunch of 8 bit chars (encoding.decoding etc). Although yep, if you ignore the fact that it is a string, with the string stuff tagged onto the side then you can go ahead and use it with gay abandon. > > As for bit-twiddling, it's rarer than you might think to have to > do more than the odd shift, OR, and AND masking, and maybe an > exclusive-OR or two for spice, and Python is well enough suited that > this isn't really an issue. Performance-wise, if you have to do > such things to a very high-bandwidth stream of data, it might run > into troubles, but (a) there are options, and (b) it hasn't bothered > me yet... If I can't twiddle bits correctly - I'm a bit stuck if I need to make a check sum from the bits in a byte array. The RSP9000 doesn't require that sort of thing (or so I thought but I controlled the RSP9000 using the Turbo Pascal interface supplied with the machine rather than direct RS232 commands) but other kit does. Also in my experience (~1 decade controlling and managing lab autoamtion) bit twiddling is something I've had to do a few times - it just depends on the interface supplied by the manufacturer. Java's not much better at this either - I ended up writing a bit twiddling class to handle this - it's just that most business apps don't need bit twiddling so it's fallen out of popularity. > > I was going to show an example from the Cavro code mentioned above, > but all it took was a few | and & operations and it's too boring > to show. Nope I'm a geek!! I couldn't find it on your website though. > > > The > > other thing that is a problem for python in this is that it is very > > difficult in python to make your your client is aware of all the errors > > that you can throw and as you know, when controlling equipment there is > > a lot of things that are out of your control (an exception that is > > rarely thrown will often not be caught if the programmer never sees it > > running and gets lazy). > > Absolutely! Uncaught exceptions would be a real pain to a customer. > > So would untested code. > By client - I mean client calling my code; not a customer - a checked exception is an excellent way of making the client calling code writer think about these errors. People who are unused to controlling machines are often unaware of the lack of control you have over yuor environment. However, test driven development is a tool that is used in many languages - not just python. Certainly in the control of machines you must test and test again - however test driven development is a tool that can be used alongside a variety of other tools such as UML, checked exceptions and stress testing (that's what I call playing Doom3 while controlling the robot with your code). TDD is not a magic wand, it's just common sense (to me anyway). > > > apps a little easier to write - although I still spent about 2 days > > trying to work out how to make a variable volatile (culminating in > > understanding the threading module!). > > All variables are "volatile" in Python, at least in most senses of > the word. I don't understand what you were doing... Exactly, because python has a GIL and can only run in one processor a variable will never need to be marked as volatile. In other systems this is something I would need to be concerned about - not in python! <snip> > You might want to investigate the use of Twisted's serial module, > which wraps around PySerial and effectively provides this, instead > of doing the polling loop approach (which, by the way, I also used > in the Cavro code but might change to Twisted in a later version). Cheers, I wrote a wrapper around PySerial to implement listeners/observers (that's what the polling loop does, Twisted probably does the same) - although if there is a published and supported implementation then I'll use that. <snip> > Actually, we *did* use ActiveX, unfortunately, because that's what > the customer wanted to use to interface LabVIEW to the driver <snip> LabView isn't a bad tool, the use of wiring metaphors appeals greatly to engineers (as you'v probably expereicend) - also it is (again IMO) one of the best graphical programming tools out there. I don;t use it because I can program and flow control in LabView is a pain but that doesn;t stop me having an a look in every now and then. > > -Peter This is my second attempt at a response - so if you get two mails back then please forgive me! Cheers, Neil

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