🌐 Mailman 3 September 2009 - Python-list - python.org

Python in Process Control?
by Wolfgang Keller March 24, 2014

March 24, 2014

Hello, is it that my know-how to use Google is insufficient or... ...does really noone use Python for industrial control applications? At least I didn't manage to find any publicly available modules for such things as OPC/fieldbus communication etc... TIA, best regards, Wolfgang Keller

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OPC for Python ?? (Win32)
by Armin Steinhoff March 24, 2014

March 24, 2014

Hi All, is there an implementation of OPC for Win32 Python available ?? ( http://www.opcfoundation.org ) Regards Armin

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Python OPC -wrapper for data collection, anyone seen it ?
by pekka niiranen March 24, 2014

March 24, 2014

Has anybody seen OPC -wrapper done in python ? In industry OPC -servers are breaking thru. It is a microsoft based technoloqy to gather process information. Many Control System manufacturers have their own OPC -servers. There exists a visual basic wrapper -library so that one write VB - programs to enquire data from OPC -server.Wrapper done to python would be cool. Mark Hammond was not interested, but I am not giving up yet... -pekka-

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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

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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?

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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

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converting a string to a function parameter
by koranthala Jan. 5, 2014

Jan. 5, 2014

Hi, Is it possible to convert a string to a function parameter? Ex: str = 'True, type=rect, sizes=[3, 4]' and I should be able to use it as: test(convert(str)) and the behaviour should be same as calling test with those values : i.e. test(True, type=rect, sizes=[3, 4]) I tried eval, but it did not work. And any other mechanism I think turns out to be creating a full fledged python parser. Is there any mechanism with which we can do this straight away?

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Problem when applying Patch from issue1424152 to get https over authenticating proxies working with urllib2 in Python 2.5
by tvashtar Dec. 10, 2013

Dec. 10, 2013

Hi, I'm trying to get https requests working through an authenticating proxy with urllib2 in Python 2.5, I'm aware that this isn't supported "out of the box", so applied the patch http://bugs.python.org/file9753/http-tunnel-urllib linked from http://bugs.python.org/issue1424152 , my baseline test program is the following: p = "user:pass@proxy:port" proxy_handler = urllib2.ProxyHandler({"http": p, "https": p}) urllib2.install_opener( urllib2.build_opener( urllib2.HTTPHandler, urllib2.HTTPSHandler, proxy_handler)) request = urllib2.Request( "https://groups.google.com") response = urllib2.urlopen(request) Unfortunately this doesn't work, the call stack being: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 121, in urlopen return _opener.open(url, data) File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 374, in open response = self._open(req, data) File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 392, in _open '_open', req) File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 353, in _call_chain result = func(*args) File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 1108, in https_open return self.do_open(httplib.HTTPSConnection, req) File "D:\p4\depot\Development\HEAD\Build\ReleaseSystem\DownloadSystem \urllib2.py", line 1075, in do_open raise URLError(err) urllib2.URLError: <urlopen error (1, 'error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol')> Does anyone know why I might be hitting this issue? Any help is greatly appreciated, thanks

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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()

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Invalid syntax with print "Hello World"
by Henrik Bechmann Nov. 14, 2013

Nov. 14, 2013

obviously total mewbiew: My first program in Python Windows print "Hello World" I select Run/Run Module and get an error: Syntax error, with the closing quote highlighted. Tried with single quotes as well. Same problem. Can someone explain my mistake? Thanks, - Henrik

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