Mailman 3 April 2018 - Python.NET

Multithreading/multiprocessing
by Alan Macdonald May 5, 2025

May 5, 2025

Hello, has anyone successfully used multithreading or multiprocessing with Python.Net? I tried to multi-thread from the .Net side and the Python.Net libraries seem to have issues in the RunScript method. I had to take an implementation off the web of that method because the shipped method doesn’t seem to work. I then had a working multi-processing example from CPython that I tried from Python.Net but it gives an error 'module' object has no attribute 'argv' When trying to create a process pool by executing the line pool = Pool(processes=4) Is it possible to do multithreading or multiprocessing with Python.Net? Thanks, Alan

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Error in calling Python class method from C#
by techi eth May 2, 2018

May 2, 2018

Hi, I am facing issue while calling python class function in C# programme. Can anyone give me hint what is wrong in below programme.While running I am getting error in invoking Initialize() function of class. Python module <Class.py> : def test(): print "Test called" return 1 class ClassTest: def __init__(self) def Initialize (): print " Initialize called" return 1 @staticmethod def Execute(): print "Execute called" return 1 C# Console Programme code snapshot : PythonEngine.Initialize(); using (Py.GIL()) { PyObject testClassModule = PythonEngine.ImportModule("Class"); //Calling module method PyObject result = testClassModule.InvokeMethod("test"); Console.WriteLine("Test method result = {0}", result.ToString()); PyObject classTest = testClassModule.GetAttr("ClassTest"); *classTest.InvokeMethod("Initialize "); -----------------------------> Error* classTest.InvokeMethod("Execute"); } PythonEngine.Shutdown();

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Using multiple versions of the same DLL
by Joe May 1, 2018

May 1, 2018

Hello, I found a rather old thread (2003) that describes how multiple versions of a DLL can be used. It states > Things get a lot more complicated if you need to load more than one > version of a particular assembly (or more likely, you have a dependency > on some library the does so). In this case, the names you access via > the CLR modules will always come from the first version of the > assembly loaded (which will always win in the internals of the > runtime). (https://mail.python.org/pipermail/pythondotnet/2003-October/000010.html) Is this still correct or are there more convenient methods to do this? Kind regards, Joe

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Embedding: finer control over module creation
by Tom Unger (eVigils) April 30, 2018

April 30, 2018

I'm starting on a project to embed CPython into a .NET application for scripting. The application currently uses IronPython, which is falling behind. Our scripting needs are fairly extensive and I'm challenged by the limited information I find available. First questions are about some finer grain control over First, my application loads a number of scripts. I currently use PythonEngine.ModuleFromString() and this works but I would like finer control. 1. Set the filename in call to Py_CompileString(). Current this is set to "none" 2. Set globals for module before executing it. I put certain values in the scripts global space for convenience. PythonEngine.Compile() will compile the code but then I don't see any way to execute the code. Runtime.PyImport_ExecCodeModule(name, c); is not public. Is there a way to do this with the current API? If I fork the GIT repo, make changes that I need, are they likely to be incorporated? Thanks, Tom

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Embedding: finer control over module creation
by Tom Unger April 26, 2018

April 26, 2018

I'm starting on a project to embed CPython into a .NET application for scripting. The application currently uses IronPython, which is falling behind. Our scripting needs are fairly extensive and I'm challenged by the limited information I find available. First questions are about some finer grain control over First, my application loads a number of scripts. I currently use PythonEngine.ModuleFromString() and this works but I would like finer control. 1. Set the filename in call to Py_CompileString(). Current this is set to "none" 2. Set globals for module before executing it. I put certain values in the scripts global space for convenience. PythonEngine.Compile() will compile the code but then I don't see any way to execute the code. Runtime.PyImport_ExecCodeModule(name, c); is not public. Is there a way to do this with the current API? If I fork the GIT repo, make changes that I need, are they likely to be incorporated? Thanks, Tom

1 0

AddReferenceToFileAndName, AddReferenceToFile
by Joe April 20, 2018

April 20, 2018

Hello, I found lots of references to AddReferenceToFileAndName and AddReferenceToFile online but could not find anything on them in the docs. Have they been removed? I looked at pythonnet/src/runtime/moduleobject.cs and there is only a single function public static Assembly AddReference(string name) which seems to handle all the cases. Kind regards, Joe

1 1

Getting handles to .NET objects, un-referencing modules
by Joe April 20, 2018

April 20, 2018

Hello, I have a .cs file that contains public struct SomeStruct { .... } public static class SomeClass { .... } So far I use it with PythonNET like import clr clr.AddReference('c:\\Test\Module.dll') from Module import SomeClass, SomeStruct SomeClass.SomeMethod(...) My problem is now that I need to work with dlls with identical names and no version number set, so PythonNET will not see them as two different dlls but as the same. Even if I import them using the full path with AddReference. Now I would like to use them as stated here https://stackoverflow.com/questions/31408391/python-for-net-using-same-net-… like x = clr.AddReference('c:\\Test\Module.dll') But how would I get the handle to SomeClass and SomeStruct ? Another way would be to un-reference the dlls after each use, as described here https://stackoverflow.com/questions/1362114/how-to-unload-a-net-assembly-re… How would that syntax look like? Kind regards, Joe

1 0

Garbage collector with Pyhton using PyhtonForNet
by techi eth April 20, 2018

April 20, 2018

I would like to know how the data structure of C# dll defined in python will get cleared from system memory. Any link or detail will be helpful to understand memory leak cased when using dotnet with python.

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How to use C# object[] in python
by techi eth April 20, 2018

April 20, 2018

I am trying to use one of data struct class defined in c# dll to python script. I am facing difficulty in adding c# object under payload. Can anyone give me hint or any example which will useful for assigning payload under object array. public class TestPayload { public string RequestId { get; set; } public byte[] ServiceIds { get; set; } public object[] Payload { get; set; } public bool IsStatus { get; set; } public long ExpiryDateTime { get; set; } } Note : I am able to add other parameter defined in class & pass from python script to c#. Thanks

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How to pass Out parameter
by techi eth April 18, 2018

April 18, 2018

Hi I have once class function in C# which is expecting out parameter. How can I pass out parameter from python. Below is signature of function. public void GetOutData(string InputData, out bool isHavingParams, out string Parm1, out int32 Parm2, out object Parm3)

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