Mailman 3 December 2007 - Python.NET

Accessing Public Functions in Module
by Kyle Stevens 18 Dec '07

18 Dec '07

We have an application that was developed in Visual Basic, and would like to use Python for .NET to extend it. I've played around with it a bit, and everything works fine if it is within a class in the .Net assembly. However, there are a number of components that exist as public functions within a module. I cannot seem to access them from Python for .NET. My latest session is shown below, where I try to import and use the function, "NonQuery" within the module, "SQL_Module" to no avail. Thanks for any help, and thanks for this wonderful piece of software. I can't wait to start programming some things with this instead of Visual Basic. Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp. Z:\>\\buffalo02\share\IT\python\python\python.exe Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import Nepco4 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named Nepco4 >>> from NepcoV2 import Order >>> from NepcoV2 import NonQuery Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name NonQuery >>> from NepcoV2 import SQL_Module.NonQuery File "<stdin>", line 1 from NepcoV2 import SQL_Module.NonQuery ^ SyntaxError: invalid syntax >>> from NepcoV2.SQL_Module import NonQuery Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named SQL_Module >>> import Nepco4.NepcoV2 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named Nepco4.NepcoV2 >>> from Nepco4 import NepcoV2 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named Nepco4 >>> from NepcoV2 import SQL_Module Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name SQL_Module >>> from NepcoV2 import SQL_Module5 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name SQL_Module5 >>> from NepcoV2 import SQL_Modulf Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name SQL_Modulf >>> from NepcoV2 import Shipping_Detail_Report >>> from NepcoV2 import * >>> NonQuery() Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NonQuery' is not defined >>> NepcoV2.NonQuery() Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NepcoV2' is not defined >>>

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Accessing class interface with private methods
by alex omoto 15 Dec '07

15 Dec '07

Hi, I am having trouble using Python.NET in accessing class interface methods that are declared private. As an example, Public Interface Iface Property Func() As Boolean End Interface Public Class Foo Implements Iface Private Function Func() As Boolean Return True End Function Public ReadOnly Property IFACE() As Iface Get Return Me End Get End Property End Class Then using Python 2.5 with Python.Net 2.0 alpha 2, I cannot access the method. Is this supported? import clr import Foo f = Foo() f.IFACE # OK f.IFACE.Func() # results in Attribute error Thanks, Alex --------------------------------- Never miss a thing. Make Yahoo your homepage.

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Re: [Python.NET] Trouble getting Python for .NET to work in Ableton Live
by Tijs Wickardt 13 Dec '07

13 Dec '07

Hi Christian, > The magic is in clr.pyd. You have to import the python dynamic extension > (hence the name) in order to use the CLR features in a common Python. > The clr.pyd in the alpha zip files doesn't work properly. You have to > compile your own version with VS. Thanks, that helps. "import clr" is indeed working with a newly built clr.pyd in a standard Python 2.5.1. After that I can import .net libraries, thanks for your help. >> Ableton comes as one big .exe (about 20MB). I'd have to hack it, and.. > > I fear it's not going to work. A big exe sounds like a static inclusion > of Python. PythonDotNET isn't compatible with static linking of the > pythoncore library. It requires a pythonXX.dll to work. Too bad. Thank you for your clear answer. Thanks, Tijs

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Re: [Python.NET] Trouble getting Python for .NET to work in Ableton Live
by Tijs Wickardt 13 Dec '07

13 Dec '07

Thanks for the reply Brian, and also Christian Heimes and Feihong Hsu. > Not sure how insane this is, but if you want to really roll your sleeves > up you might be able to checkout the old python2.2-supporting branch of > python.net and build it using the .NET 2.x tool chain. I'll look into that, thanks > > If it works (no guarantees, but it might), then you should at least be > able > to load .net 2.x assemblies, though you wouldn't be able to leverage > features that were supported in .net 1.0. > This shouldn't be too much of a restriction. If I build my assemblies with .net 2.0 it should ( /might) work? On problem though - how do i use the "pythonnet-2.0-alpha2" anyway in a separate python? Can't seem to find anything about it in the docs. I can build it using VS2005, but that gives me a python.exe and a "Python.Runtime.dll", which I suspect is where all the magic is. If I say "import Python.Runtime" from a normal python.exe, I get the message the following: >>> import Python.Runtime Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named Python.Runtime I guess what I'm doing doesn't make sense at all, Python.Runtime.dll is probably a .net assembly. But how then? > I don't know much about Ableton (I'm a Sonar guy...), but if they haven't > done anything too weird to the python they ship with you could also > investigate dropping in a newer python exe, dlls and libs... > Ableton comes as one big .exe (about 20MB). I'd have to hack it, and have no idea how to do that... > -Brian Thanks, Tijs P.S. Feihong: Using popen2 wouldn't be the best workaround for me I think. Liveapi has a telnet and OSC server that would probably serve me best. I'd prefer to use .net directly however, and save me the overhead of socket traffic. If it's not possible, it's not possible, and I'll use liveapi. Thanks again, Tijs

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Trouble getting Python for .NET to work in Ableton Live
by Tijs Wickardt 12 Dec '07

12 Dec '07

Hi group, I'm new here, so let me start with a small introduction: I'm a Progress developer (RDBMS with it's own 4GL) for a living, with some experience in C++ and C#, and I'm into music. Python is new to me, but doesn't seem so hard to learn (at least the basics). So sorry beforehand for some silly questions which I should have posted at a Python noob forum ;) Here's the question: The provided examples with Python for .NET run fine with the supplied python.exe on my Win32 XP SP2. I previously had problems with using the CLR.dll (Python .NET 1.0) inside a default Python 2.4.4 installation, and asked Brian Lloyd about this, but it was apparently an installation problem; now, on another machine, this imports fine (import CLR). It was a Python 2.5.1 installation on the other machine, maybe that's the difference. What I'd really like to do however, is the following: In a music program called Ableton Live, Python scripts are used to make interfaces between hardware midi controllers and Ableton Live. I'd like to use Python for .NET here, since I have several C# libraries I'd like to use for my mappings (and other stuff). When I copy "Python.Runtime.dll" and "CLR.dll" to a subfolder with a python script of Ableton Live, it compiles into .pyc. Ableton Live however gives a message "A serious error has occured", and on shutdown of the program, a memory fault causes the MS debugger to launch. Not good. Is what I want possible? Should I add more code to the .py scripts? The only thing I've added was "import CLR" in the first line of "__init__.py" (plus a newline character oc). Should I use a CLR.dll for Python 2.2, and does that exist? With the Python for .NET 2.0, I don't see a CLR.dll anymore. Only a "clr.so" of which I have no clue, and doesn't import. How should I use it? Here is some more info on Ableton Live's Python implementation (quoted from www.liveapi.org, which is down at the moment): # The current limitations that really stand out are: Ableton's Python environment is based on a stripped down Python 2.2 install # Updates are limited to 60ms (16 times a second) # Threads in Ableton's Python environment are only polled every 100ms, sys.setcheckinterval() doesn't seem to affect this. # No select.py seems to work, although we suspect that this could be easily resolved with some additional effort. There's an incompatibility between Ableton's Python and the 'standard' Python 2.2 major release. They appear to be different flavors. Any help appreciated, Kind regards, Tijs Wickardt

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Re: [Python.NET] Accessing class interface with private methods
by Tijs Wickardt 11 Dec '07

11 Dec '07

Actually, there is a way to access private members in C#. You can use System.Reflection to modify access directives. Since you can't access private members from Python .net, you could write a seperate C# module that unhides private members and exposes them as public. You could then call those public methods from Python for .NET. Cumbersome, but should work. Kind regards, Tijs Feihong Hsu hsu.feihong at yahoo.com Sun Dec 9 15:54:23 CET 2007 Previous message: [Python.NET] Accessing class interface with private methods Next message: [Python.NET] Structure as argument Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] -------------------------------------------------------------------------------- This is not supported. You can't access private methods in C# or VB.NET either, so why should Python.NET be able to access them? But one thing to note is that you CAN access protected methods directly in Pyhon.NET (you don't have to make a subclass to use a protected method). - Feihong alex omoto <lance23runner at yahoo.com> wrote: Hi, I am having trouble using Python.NET in accessing class interface methods that are declared private. As an example, Public Interface Iface Property Func() As Boolean End Interface Public Class Foo Implements Iface Private Function Func() As Boolean Return True End Function Public ReadOnly Property IFACE() As Iface Get Return Me End Get End Property End Class Then using Python 2.5 with Python.Net 2.0 alpha 2, I cannot access the method. Is this supported? import clr import Foo f = Foo() f.IFACE # OK f.IFACE.Func() # results in Attribute error Thanks, Alex

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Structure as argument
by alex omoto 08 Dec '07

08 Dec '07

Hi again, I am basically trying to integrate some python code with already built VB code. I'd prefer not to have to change VB code, but here are the things i noticed... (1) All VB optional arguments must be defined when calling them in Python.Net. (2) I have created a function with a structure as the argument. Public Structure SomeStruct Public dVal As Double End Structure Public Class Class1 ... Public Function test(ByRef arg As SomeStruct) As Boolean return True End Function End Class Using Python.Net, I can create the class, then the struct and call the function with the struct as the argument. I get the following error: System.ArgumentException: Object of type 'System.RuntimeType' cannot be converted to type 'SomeStruct&' Thanks, Alex --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.

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