Mailman 3 July 2010 - Python.NET

how can I build an assembly I can AddReference()?
by Brandon Craig Rhodes Aug. 17, 2010

Aug. 17, 2010

I am interested in whether Python for .NET can help me provide third-party programmers with a way to write C# routines that will get called from my Python application. I was impressed earlier today with how easily Python for .NET compiled for Python 2.6 and the most recent Visual Studio release, so I set about trying to write a C# routine and call it from inside of Python. I have only gotten as far as trying to AddReference() my new DLL, but have not been able to get it to succeed. I first created a "Brandon.cs" file with this inside: ---------------------------------------- using System; using System.Reflection; [assembly:AssemblyVersion("1.0.0.0")] [assembly:AssemblyDescription("The Brandon library")] [assembly:AssemblyCompany("Rhodes Mill Studios, Inc.")] namespace Brandon { public static class BrandonClass { public static void Go() { Console.WriteLine("Hello, World!"); } } } ---------------------------------------- This was simple enough to compile with: csc /t:library Brandon.cs which produced a "Brandon.dll" file. Look at what happens if I then try importing that DLL from Python for .NET: >>> import clr >>> print clr.FindAssembly('Brandon') C:\Users\brandon\dev\pythonnet\Brandon.dll >>> clr.AddReference('Brandon') ... System.IO.FileNotFoundException: Unable to find assembly 'Brandon'. at Python.Runtime.CLRModule.AddReference(String name) in c:\Users\brandon\dev\pythonnet\src\runtime\moduleobject.cs:line 370 You can see that, oddly enough, Python can find the assembly, but cannot create a reference to it. This error message also results, by the way, if I compile "Brandon.cs" with a "/keyfile:..." option and run "gacutil /i Brandon.dll" before trying to run my Python code. I know that the step I am missing is probably blazingly obvious to those who have been using Windows longer, :-) but I will very much appreciate whomever who can point out what critical step I am missing in getting my Python code to call C# code. Other than this hangup, I'm impressed by how quickly Python for .NET got me up and running! -- Brandon Craig Rhodes brandon(a)rhodesmill.org http://rhodesmill.org/brandon

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Selecting an overloaded contructor
by Barton July 28, 2010

July 28, 2010

The readme clearly states that from System import String, Char, Int32 s = String.__overloads__[Char, Int32]('A', 10) should select the desired constructor, but ... there is clearly no means in the current (2.0.0.2) version for a ClassObject to activate the search by means of __getattribute__ (no tp_getattro). Is this something that worked in an earlier version? Where there changes that were made that were not committed to the trunk? Is this something that anybody else has come up against? fixed??? Thanks, all, Barton Windows 7, Framework Version: 2.0.50727.42 (AFAIK) Python 2.6.5

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Some super basic/possibly stupid question
by Joachim de Lezardiere July 13, 2010

July 13, 2010

Hello Brian, I have looked at the help and nobody seems to be having my problem: 1. I install PythonNet (pythonnet-1.0-rc2-py2.3-clr1.1) at C:\Python27 2. Cmd and then, cd C:\Python27 3. Python.exe 4. Then I type: from System import String 5. And I get the error: No module named System. L Which is true, there are no module on my computer called System. So how can I import a module that doesn't exist ? Sorry for this possibly stupid question , Thanks, Joe

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