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

rpc implementation
by Zajcev Evgeny Sept. 1, 2000

Sept. 1, 2000

I want to use RPC interface via python programming is there any rpcgen_like compilers for Python?? -- zev

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SAX Xml Problem
by Darren Young Sept. 1, 2000

Sept. 1, 2000

I am getting the following error: Reading /usr/local/src/yhl/src/installer/manifext.xml Traceback (innermost last): File "./dl.py", line 29, in ? parser.parseFile(file) File "/usr/lib/python1.5/site-packages/xml/sax/drivers/drv_pyexpat.py", line 77, in parseFile if not self.parser.Parse(fileobj.read(),1): AttributeError: 'string' object has no attribute 'read' When I run the following code: #!/usr/bin/python # from xml.sax import saxexts from xml.sax import saxlib class FindSource(saxlib.HandlerBase): def __init__(self, name): self.search_name = name def startElement(self, elemName, attrs): print "Starting element: ", name #if elemName != 'source' : return name = attrs.get('name', None) if name == self.search_name: print name, 'found' if __name__ == '__main__': file = "/usr/local/src/yhl/src/installer/manifest.xml" print "Reading", file parser = saxexts.make_parser() dh = FindSource('Bash') parser.setDocumentHandler(dh) parser.parseFile(file) parser.close() Any ideas would be wonderful... Thanks, Darren Young

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

Sept. 1, 2000

Actually, the range vs. xrange thing was just a very minor alteration, the primary change was the use of the "first", "second", and "current" variables in place of the n-length list cache. This does make a considerable difference on my machine, the memory for the list version taking over 155 MB for a 100,000 run(before bringing my computer to its knees), while the variable version takes no more than 7.5 MB (before completion). Strangely, I'm not in the fibonacci-generating business either! I'm just a slightly strange designer who jumped at the chance to return the "optimisation" threads to Python List, and apparently over stepped the bounds of proper society in doing so. My apologies. But in case you're curious, the fibonacci number for 1,000,000 is here (run time ~24 minutes on a PIII 500): http://members.home.com/mcfletch/programming/fibonacci_1000000.txt Here's the version used for that: def fibonacci2 (n) : if n < 2: return n else: first = 0L second = 1L for i in xrange (2, n+1) : first, second = second, first + second return second Enjoy yourself, Mike -----Original Message----- From: tanzer(a)swing.co.at [mailto:tanzer@swing.co.at] Sent: Friday, September 01, 2000 3:07 AM To: python-list(a)python.org Subject: Re: Python in game development? + recFib Mike Fletcher <mfletch(a)tpresence.com> wrote: > 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)). Well, I'm not in the business of playing with x-large fibonacci numbers. And sure, one should adapt one's algorithm to the problem to be solved. You might overrate the negative effects of using lists of 100000 elements, though. For instance, on my system with 160MB main memory it hardly makes any visible difference whether you use `xrange (2, n+1)' or `range (2, n+1)' for n==100000 -- procmeter just shows a tiny dip in free memory for the `range' version (the speed of your fibonacci2 is the same for both `range' and `xrange', too). My-original-point-in-this-thread-wasn't-really-optimization- of-fibonacci-algorithms, 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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Re: Oracle and Python
by Bill Scherer Sept. 1, 2000

Sept. 1, 2000

Philip Rodgers wrote: <snip> > Python 1.6b1 (#1, Aug 31 2000, 13:50:21) [GCC egcs-2.91.66 19990314/Linux] on linux2 > Copyright (c) Corporation for National Research Initiatives. > Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam. > >>> import DCOracle > >>> db = DCOracle.Connect("myuser/mypass@iphonex") > >>> cursor = db.cursor() > >>> cursor.execute("select distinct owner from sys.all_tables") > Traceback (most recent call last): > File "<stdin>", line 1, in ? > File "/usr/local/lib/python1.6/DCOracle/ociCurs.py", line 271, in execute > r = self._execute(params__, kw) > File "/usr/local/lib/python1.6/DCOracle/ociCurs.py", line 213, in _execute > out=self._describe(self._ft) > File "/usr/local/lib/python1.6/DCOracle/ociCurs.py", line 173, in _describe > out.append(buf,dbsize,dbtype,ind,alen,arcode, f) > TypeError: append requires exactly 1 argument; 7 given <snip> Aha! This is what you get for using a beta release <wink>. Apparently Jim Fulton, who wrote DCoracle, was using the undocumented but functional feature of append that allowed multiple arguments in releases up to 1.5.2. This has been removed in 1.6. (forgive me if I got the history/details wrong here) To fix, you have two choices. 1. Use Python 1.5.2 2. change line 173 in _describe to: out.append((buf,dbsize,dbtype,ind,alen,arcode, f)) This is, of course, untested, and there may be other places where the code will fail for the same reason. I say try it, and see what happens. - Bill Scherer

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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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PyErr_Occurred - how to use results?
by Richard Harvey Sept. 1, 2000

Sept. 1, 2000

I have Python embedded in a C/C++ application, and I'm calling user defined Python scripts that themselves can call back into my application. Right now I'm having problems when an error occurs in a script; I haven't found a clean way to report errors back within my application. I've been browsing various code samples that reroute stderr, but I can't see how I can route these back to a C function for display. So, I'm taking a look now at PyErr_Occurred. This function appears to do exactly what I want by returning the last raised exception. However, now that I have the PyObject* result, how can I decode this object to get an error number, string, and line number? I hoped this would be something like a dictionary object where I could choose which keys I'm interested in and display the error to the user, but it appears this is the actual exception object itself. Can anyone point me in the right direction, either by how to decode PyErr_Occurred from the C API, or setting the global stderr to call back into my C code with objects/strings that can be evaluated in C for output? I'm quite impressed by what PythonWin pulled off, by offering source level debugging on top of the Python engine from a C application. Rich

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memory leak in debug dll for windows
by nick_knight＠my-deja.com Sept. 1, 2000

Sept. 1, 2000

Hello I am embedding pythoon in an app but when purley doing the following: - void main() { Py_Initialize(); //do nothing Py_Finalize(); } this when using the debug Dll cuases a couple of memory leaks but not in the non - debug dll. Has anyone else seen this. Python ver 1.5.2 VSVC 6 Thanks Nick 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: EXTREME NOOB, lists?
by Steve Holden Sept. 1, 2000

Sept. 1, 2000

skeetor wrote: > > I am trying to compare an input number with several numbers in a list, and > then to print the range of that number. for example: I have it ask for a > number, and i reply with 4. I want it to check to see if 4 is in the list > and if so print the range. I have solved the problem by writing out the > argument for each number in the list... but it is very long. I hope i have > explained this accurately. and please i am still a retarded four year > old... so talk slowely and use small words. thanks. The index() method of a list will do this for you, but you need to be aware that it will throw an exception if the item isn't found in the list, so you must use try: except: to trap that case. >>> l = [4,5,2,3,11] >>> l.index(11) 4 >>> l.index(42) Traceback (innermost last): File "<pyshell#55>", line 1, in ? l.index(42) ValueError: list.index(x): x not in list >>> try: pos = l.index(42) except ValueError: print "Could not find 42" Could not find 42 Just another example of how wonderful Python is! regards Steve -- Helping people meet their information needs with training and technology. 703 967 0887 sholden(a)bellatlantic.net http://www.holdenweb.com/

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