🌐 Mailman 3 December 2006 - Python-list - python.org

Writing an OPC client with Python ?
by pierlau March 24, 2014

March 24, 2014

Hello, I use an OPC server for connection to DC Drive. I would like to write a small OPC client. I have the dll OPCDAAuto.dll which contains all class and method but I wonder if its possible to instance in python the class that are in the dll ? Thanks for your help . Pierre

6 6

newbie - Does IDLE care about sitecustomize.py?
by bobueland＠yahoo.com March 22, 2014

March 22, 2014

I have the following test script in the file customize.py # C:\Python24\Lib\site-packages\sitecustomize.py print "test text from sitecustomize" If start Python from command prompt I get C:\Python24>python test in sitecustomize Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. which shows that sitecustomize.py works Now if I start IDLE I only get IDLE 1.1.1 >>> which shows that that IDLE doesn't care about sitecustomize.py Am I missing something or how do you customize if you are using IDLE?

4 3

Editor for Python
by MANUEL FERNANDEZ PEREZ Jan. 9, 2014

Jan. 9, 2014

Hello, I'm looking for an editor for Python.I' m interested it works on Windows.Can anybody help me? Thank you Manuel

20 23

Sine wave?
by EC Nov. 25, 2013

Nov. 25, 2013

Ive been banging my head against the wall for the past few days trying to generate a sine wave... My math skills arent the best, I'll admit, and I think I'm going crosseyed trying to understand this... I *think* the following code should work but it outputs some really weird stuff. I'm sorta new so please help if you can! Thank you Eric #------------------------------------------- import math import wave import string pi = math.pi sin = math.sin cos = math.cos #init output and related vars sr = 44100 Outfile = wave.open("outfile.wav", "w") Outfile.setnchannels(1) Outfile.setsampwidth(4) Outfile.setframerate(sr) Outfile.setcomptype("NONE", "Uncompressed") Outtemp = [] Outstr = "" def get_phase(curphs, freq): phinc = (freq*1.0000/sr*1.0000)*360 phase = curphs + phinc if phase >= 360: phase -= 360 elif phase < 0: phase += 360 return phase def gen_wav(sec, freq, ampcent): numsamp = sec*sr amp = (ampcent*1.0000/100)*32767 i = 0 temp = [] t = 0 curphase = 0 while i < numsamp: curphase = get_phase(curphase, freq) t = int(round(amp*sin(2*pi*curphase))) temp.append(t) i+=1 return temp Outtemp = gen_wav(.01, 440, 75) Outstr = string.join(map(str, Outtemp), ",") print Outstr Outfile.writeframes(Outstr) Outfile.close()

7 9

Re: Proposal: [... for ... while cond(x)]
by Eighty Sept. 26, 2013

Sept. 26, 2013

Terry Reedy wrote: > whereas the analogous expansion of your proposal > > for x in xs: > while cond(x): > yield e(x) > > is an infinite loop and not at all what you mean. You're right. The syntax is ambiguous. I agree it's not a good idea, now. :) > x for x in xs while cond(x) if blah(x) > x for x in xs if blah(x) while cond(x) > x*y for x in xs while cond(x) for y in ys These wouldn't be a problem. "... for x in xs while cond(x) ..." would be transformed into "... for x in takewhile(cond, xs) ..." which could be applied to an if thingy if you first transform "... for x in xs if cond(x) ..." into "... for x in filter(cond, xs) ...".

2 2

mutlifile inheritance problem
by maurelius01＠hotmail.com Sept. 21, 2013

Sept. 21, 2013

I have classes defined in different files and would like to inherit from a class in file A.py for a class in file B.py but am running into problems. I'm using Python 1.5.2 on Windows NT Here's a specific example: ************************ file cbase01.py: class CBase: def __init__(self): self.cclass = None print "cbase" class CImStream(CBase): def __init(self): CBase.__init__(self) print "CImStream" ************************* in file wrappers_A01.py: import cbase01 reload(cbase01) class ImStream_SavedBitmaps(cbase01.CImStream): def __init__(self): cbase.CImStream.__init__(self) print "SavedBitmaps" ************************** in file sequencer01.py import cbase01 # the offending lines, program works reload(cbase01) # if I comment these out. class Sequencer: def Append(self, item): pass ***************************** in test02.py import wrappers_A01 reload(wrappers_A01) import sequencer01 reload(sequencer01) x0 = wrappers_A01.ImStream_SavedBitmaps() *************************************************************** If I run test02 I get the traceback Traceback (innermost last): File "<string>", line 1, in ? File "D:\PythonCode\pna\eyeTracking\tests\test02.py", line 15, in ? x0 = wrappers_A01.ImStream_SavedBitmaps() File "D:\PythonCode\pna\eyeTracking\tests\wrappers_A01.py", line 21, in __init__ cbase.CImStream.__init__(self) TypeError: unbound method must be called with class instance 1st argument Any ideas what I am doing wrong? Thanks, Marc

11 21

can't find win32api from embedded pyrun call
by Jim Sept. 6, 2013

Sept. 6, 2013

I am trying to figure out how to embed Python in a little C++ Windows console app. Here's the code: // Py_Initialize(); Py_InitializeEx(0); PyRun_SimpleString("from win32com.client import *"); Here's what it does on the last line: File "D:\Python\Lib\site-packages\win32com\__init__.py", line 5, in ? import win32api, sys, ok ImportError: No module named win32api The same line runs fine in IDLE or at the command prompt. It also runs without complaint if I run a release version of the app. To build the debug version I had to build python42_d.lib/dll myself. The reason I can't call PyInitialize is that it crashes with an "invalid signal" error. I don't think it's a path issue -- I've checked system path, sys.path, pythonpath env var, and the pythonpath entry in the registry, all of them loaded with directories including the one with win32api.pyd. Besides, if it were an install or path problem, why would it work at the command prompt? Could it be a problem with the debug lib I built? Any suggestions are welcome. -- Jim

4 6

Best Python book(s) for a pre-teen?
by snarflemike＠yahoo.com Aug. 1, 2013

Aug. 1, 2013

Hi all, My son is 11 and wants to try programming, partly because it's what I do for a living. Even though I don't (yet?) use or even know Python, through some unexplainable thought process I've decided it would be a good language to start him off with. I've downloaded 2.2.2 and played around with it for a bit, and I would now like to hand him a book (with my guidance as needed) and say "go have fun!" Is there a book that would be suitable for this approach (again, assuming I'm around to help out as needed)? One other question -- I'd like him to be able to do simple graphics fairly early, since I think it makes the whole self-learning process much more interesting. I'm talking about things like points, lines, circles, fills, etc. Is there a binding to the Win32 graphics primatives in 2.2.2, or can I find one someplace? If this is a RTFM question, any pointers to TFM chapter, etc would be appreciated! Thanks for any guidance. I'm sure I'll end up having at least as much fun as he does. Mike

15 15

Weirdness with python and stdin redirection under Win32
by Jonathan M. Gilligan Jan. 18, 2013

Jan. 18, 2013

I am getting an error reading stdin only when I invoke a python script by typing "bar | foo.py" or "foo.py < bar", but not when typing "bar | python foo.py" or "python foo.py < bar". The error arises ecause when input is redirected, stdin has fileno = -1 if the script is invoked as "foo.py", but correctly has fileno = 0 if it is invoked as "python foo.py" Consider the following script, which I want to use as a prototype for a simple stdin --> stdout filter: # foo.py import sys print "fileno = ", sys.stdin.fileno() lines = sys.stdin.xreadlines() for line in lines: sys.stdout.write(line) On win32 (Win2k pro, SP3), using ActiveState ActivePython 2.2.1 build 222, I can execute foo.py either by typing "foo.py" or "python foo.py" on the command line (the relevant registry key for opening .py files has command 'C:\Python22\python.exe "%1" %*'). If I type "echo bar | foo.py", I get C:\>echo bar | foo.py The process tried to write to a nonexistent pipe. fileno = -1 Traceback (most recent call last): File "C:\foo.py", line 7, in ? lines = sys.stdin.readlines() IOError: [Errno 9] Bad file descriptor whereas if I type "echo bar | python foo.py", I get C:\>echo bar | python foo.py fileno = 0 bar Other tests yield: C:\>foo.py < foo.py fileno = -1 Traceback (most recent call last): File "C:\Documents and Settings\Jonathan\My Documents\Programming\Omap VU\Fast CameraDriver\BF_LabView\Leo\foo.py", line 7, in ? for line in lines: IOError: [Errno 9] Bad file descriptor C:\>python foo.py < foo.py fileno = 0 # foo.py import sys print "fileno = ", sys.stdin.fileno() lines = sys.stdin.xreadlines() for line in lines: sys.stdout.write(line) If I just type "foo.py" or "python foo.py" on the command line, I get "fileno = 0" in both cases and the script works identically in both cases. Can anyone explain what's happening? Why the file descriptor for redirected stdin has a fileno of -1 if the python script is invoked using "foo.py" but not when it's invoked with "python foo.py"? Thanks, Jonathan

7 10

PHP vs. Python
by stephen.mayer＠gmail.com Sept. 25, 2012

Sept. 25, 2012

Anyone know which is faster? I'm a PHP programmer but considering getting into Python ... did searches on Google but didn't turn much up on this. Thanks! Stephen

20 22