🌐 Mailman 3 August 2000 - Python-list - python.org

Programming Python edition
by Stijn van Dongen Sept. 1, 2000

Sept. 1, 2000

Hi, I am looking for a good reference book on Python, and from what I saw at the bookstore `Programming Python' by Mark Lutz seems the best choice. The only thing is, it was written in 1996. Is a new edition due? Is the 1996 edition still just fine? Are there other books I should consider? (being a reasonably experienced programmer detesting the `Dummies', `unleashed', `10 days' etc kind of book). Stijn -- Stijn van Dongen Centre for Mathematics and Computing Science (CWI) Kruislaan 413 1098 SJ Amsterdam GO @ _ @ tel: +31 20 5924180 stijnvd(a)cwi.nl HandTalk (_'/_/ _) -- Stijn van Dongen Centre for Mathematics and Computing Science (CWI) Kruislaan 413 1098 SJ Amsterdam GO @ _ @ tel: +31 20 5924180 stijnvd(a)cwi.nl HandTalk (_'/_/ _)

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Sockets
by karlsass＠my-deja.com Sept. 1, 2000

Sept. 1, 2000

I have a set of spiders running on my system, The spiders communicate with a urlserver & a processing server via internal sockets. The spiders are the only ones using Inet sockets. Yet after a while of say 1 or 2 spiders, a urlserver and process server running , say for 3 hours, then all of a sudden the system disallows any connections to the outside, eg inet sockets as well as Netscape cannot connect to other web located resources. The urlserver just recieves and sends urls and the process server just mines pages and fill a secondary database. I am running red hat 6.2 on an intel arch based dell. It was bought 2 months ago. And all daemons appear to be running, inetd, portmap, etc..... Does any one have any ideas about what is causing the lockout or crash. The only way to solve it to reboot the machine. Netstat cannot complete it's report It does not print out the gateway?. After the crash the internal sockets still appear to be working, since no exceptions occur. I am running Python 1.52. I am now going to make sure all sockets are being shutdown. But any help would be grateful. Thanks, Karl. Sent via Deja.com http://www.deja.com/ Before you buy.

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Re: Pronouncing "print>>"
by jmcbray＠carcosa.net Sept. 1, 2000

Sept. 1, 2000

>>>>> "DS" == Dan Schmidt <dfan(a)harmonixmusic.com> writes: DS> Carey Evans <c.evans(a)clear.net.nz> writes: >> While I don't really like the new print syntax, I've decided to accept >> it. This leaves me with the problem of how to say it out loud. DS> I'll probably say "print into". DS> My usual pronunciation of >> is a quick 'urh urh' but unfortunately I DS> pronounce << the same way. Same problem with "wacka wacka", which would be my preferred pronunciation. -- +-----------------------------------------------------------+ | Jason F. McBrayer jmcbray(a)carcosa.net | | A flower falls, even though we love it; and a weed grows, | | even though we do not love it. -- Dogen |

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Modifying Python parms passed to C function?
by www.nkn.net Sept. 1, 2000

Sept. 1, 2000

I've been creating some C extension functions, and up until now have used dictionaries to mimic C-style structs. Since dictionaries are returned as a borrowed reference from PyArgs_ParseTuple I've been able to modify the dictionary and return results back to Python. Now I'm running into a problem with 'basic' types, such as ints and floats. What I want to do is essentially mimic a functions like this: int myFunc(int *parm1, float *parm2) { *parm1 = ... *parm2 = ... return 1; } Looking over the Python C API, I can see no way of pulling this off. If I extract the two params into a native int and float type with PyArgs_ParseTuple, then of course any mods I make to those variables are within my local stack frame, and do not affect the passed parameters. I can instead ask PyArgs_ to parse out the PyIntObject and PyFloatObject params as Python objects, but I can see no way to assign a new value into these using the C API. This seems like such a basic necessity that I'm sure I'm simply overlooking it in the documentation. Can anyone point me in the right direction? Rich

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RE: Python in game development? + recFib
by Mike Fletcher Sept. 1, 2000

Sept. 1, 2000

The problem with that particular implementation (elegant as it is) is that you wind up creating a cache of potentially hundreds of thousands of integers when you only need two for the next value (as far as I can see, anyway) here is a somewhat faster version of the same algorithm when you're dealing with fairly large numbers (such as fibonacci (100000)). 8<________ fibonacci.py ___________ def fibonacci (n, cache = [0L, 1L]) : for i in range (len (cache), n+1) : cache.append (cache [i-1] + cache [i-2]) return cache [n] def fibonacci2 (n) : if n == 0: return 0 elif n == 1: return 1 else: first = 0L second = 1L for i in xrange (2, n+1) : current = first + second first = second second = current return current if __name__ == "__main__": import time t = time.clock() a = fibonacci( 10000 ) print 'fibonacci', time.clock()-t ## t = time.clock() ## a = fibonacci( 100000 ) ## print 'fibonacci', time.clock()-t t = time.clock() b = fibonacci2( 10000 ) print 'fibonacci2', time.clock()-t t = time.clock() b = fibonacci2( 100000 ) print 'fibonacci2', time.clock()-t print 'a == b', a==b and a sample run... p:\>fibonacci fibonacci 0.250045676184 fibonacci2 0.136871826762 a == b 1 fibonacci2 11.9150154796 1 1 1 1 2 2 Yay! The optimisation threads return to the Python List :o) ! Enjoy, Mike -----Original Message----- From: tanzer(a)swing.co.at [mailto:tanzer@swing.co.at] Sent: Thursday, August 31, 2000 2:31 AM To: python-list(a)python.org Subject: Re: Python in game development? + recFib "Darrell Gallion" <darrell(a)dorb.com> wrote: > Hacked up Christian's code to get past the stack limit. > Skipped locking on things like the cache since it's a write once kind of > thing. > Guess hacking can pay off. (snip -- 90 lines of code) There's an easier way: def fibonacci (n, cache = [0L, 1L]) : for i in range (len (cache), n+1) : cache.append (cache [i-1] + cache [i-2]) return cache [n] # end def fibonacci And it's more efficient, too (for n=10000, it's 50% faster than my version with the dict; for n=16383, it's almost 3 times faster than your version). Simple-is-often-faster-than-complex ly, Christian -- Christian Tanzer tanzer(a)swing.co.at Glasauergasse 32 Tel: +43 1 876 62 36 A-1130 Vienna, Austria Fax: +43 1 877 66 92 -- http://www.python.org/mailman/listinfo/python-list

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XML creation
by Curtis Jensen Sept. 1, 2000

Sept. 1, 2000

We have several arrays, some are multidimensional arrays, created with NumPy. We'd like store these arrays in an XML data structure. Is there a python script similar to shelve or pickle that will take an array and convert it to XML code? Thanks. -- Curtis Jensen cjensen(a)bioeng.ucsd.edu http://www-bioeng.ucsd.edu/~cjensen/ FAX (425) 740-1451

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Re: [Python-Dev] Re: [PEP 224] Attribute Docstrings
by M.-A. Lemburg Sept. 1, 2000

Sept. 1, 2000

Aahz Maruch wrote: > > [p&e] > > In article <39AAA306.2CBD5383(a)lemburg.com>, > M.-A. Lemburg <mal(a)lemburg.com> wrote: > > > >class A: > > " Base class for database " > > > > x = "???" > > " name of the database; override in subclasses ! " > > > > y = 1 > > " run in auto-commit ? " > > > >class D(A): > > > > x = "mydb" > > """ name of the attached database; note that this must support > > transactions > > """ > > > >This will give you: > > > >A.__doc__x__ == " name of the database; override in subclasses ! " > >A.__doc__y__ == " run in auto-commit ? " > >D.__doc__x__ == """ name of the attached database; note that this must support > > transactions > > """ > >D.__doc__y__ == " run in auto-commit ? " > > > >There's no way you are going to achieve this using dictionaries. > > Maybe I'm dense, but what about > > A.__docs__['x'] == " name of the database; override in subclasses ! " > A.__docs__['y'] == " run in auto-commit ? " > D.__docs__['x'] == """ name of the attached database; note that this must support > transactions > """ > D.__docs__['y'] == " run in auto-commit ? " > > If D.__doc_y__ or D.__docs__['y'] is a reference to A.__docs__['y'], > then it's a reference either way. Conversely, if it's *not* a > reference, there's *definitely* no problem. Ok, some questions: How would this be done for mixin classes ? What if you change the base classes of D after creation of D ? How would D.__docs__ get the information about A's y attribute and when ? -- Marc-Andre Lemburg ______________________________________________________________________ Business: http://www.lemburg.com/ Python Pages: http://www.lemburg.com/python/

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quopri (quoted-printable) problem
by Dieter Maurer Sept. 1, 2000

Sept. 1, 2000

I recognized today, that * Python's "quopri.encode" encodes "=" as "==" * Both Netscape Mail and Outlook Express do not handle an "==" for "=" correctly in some circumstances. While there is apparently no problem with plain text, attribute assignments in HTML tags are no longer recognized. E.g. '<a href="#x">' is encoded as '<a href=="#x">'. If this link is clicked on, the mail reader tries to access '///'. For mail reading programs it is probably best to encode '=' as '=3D'. Dieter

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Access control in classes
by Fernando Rodriguez Aug. 31, 2000

Aug. 31, 2000

Hi! How can I implement some access control in my classes (equivalent to C++'s private, public, protected, etc...)? O:-) TIA

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Python and R
by dominic_barraclough＠my-deja.com Aug. 31, 2000

Aug. 31, 2000

Hi, I interested in doing some automated data analysis using R as the processer but driving the process with python. Has anybody attempted to do this? There is a com interface to R at the R site but I have be un able to get it to work with python - although it works with a test vb app. has any body been able to drive r with python via com Dominic Sent via Deja.com http://www.deja.com/ Before you buy.

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