Mailman 3 July 2022 - 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

2 1

convert python.runtime.pyobject to .net datatype
by anilshrirao＠gmail.com July 23, 2022

July 23, 2022

Hi, Does anyone know how to convert the pyobject dataype to .net datatype? I need to send the image from python to .net code. Thanks,

1 0

TypeError: No method matches given arguments for SetContext: (<class 'int'>)
by Steven Manross July 15, 2022

July 15, 2022

I got my initial code working on the C DLL and it's creating snapshot sets as I want. I am now having a problem with a function to query ALL the snapshots. This value can be sent to SetContext() In [39]: alphavsslib.VssSnapshotContext.All Out[39]: 4294967295 4294967295 = 0xFFFFFFFF A sample of the call is here: https://github.com/alphaleonis/AlphaVSS-Samples/blob/8482e83dd13cb8467860e8… # this is the declaration of SetContext virtual void SetContext(VssSnapshotContext context); This is the declaration for All: VssSnapshotContext.All = 0xFFFFFFFF https://github.com/alphaleonis/AlphaVSS/blob/13462e657f7993da5c80f835d219bb… However, this line results in a Type error In [40]: ctx = cmp.SetContext(alphavsslib.VssSnapshotContext.All) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) Input In [40], in <cell line: 1>() ----> 1 ctx = cmp.SetContext(alphavsslib.VssSnapshotContext.All) TypeError: No method matches given arguments for SetContext: (<class 'int'>) I've tried converting the value using: ctx = cmp.SetContext(System.Convert.ToUInt32(alphavsslib.VssSnapshotContext.All)) *And* ctx = cmp.SetContext(ctypes.c_uint32(alphavsslib.VssSnapshotContext.All).value) but the same error occurs I can get the function to succeed (albeit it doesn't show me what I want) with this: cmp.SetContext(ctypes.c_int32(alphavsslib.VssSnapshotContext.All).value) ... because ctypes.c_int32(alphavsslib.VssSnapshotContext.All).value = -1 I believe it's possible that this could be related to the link below but I can't be sure because I am not a C developer and I can't determine how this was fix from the notes in the link. Granted, the author is on CentOS, and I'm on Windows... but the backstory behind the issue sounds like it's related. https://github.com/pythonnet/pythonnet/issues/950 I'm currently running on pythonnet 2.5.2 and Python 3.9.13 (tags/v3.9.13:6de2ca5, May 17 2022, 16:36:42) [MSC v.1929 64 bit (AMD64)] on win32 Any thoughts or suggestions would be greatly appreciated. Steven

2 2

pythonnet crashes python 39
by Florin Atasiei July 12, 2022

July 12, 2022

Hello gutlys, thanks for the good work I encountered a problem on all 3.0.0 versions. I have a small exe written in C# that opens up a python process and then puts it to execute python modules. On one od the modules I have import clr. When it imports that module I get Fatal Python error:take_gil: NULL tstate and then python crashes and also the main thread from my program. This is not happening on 2.5.2 release but with that i have other problems since is not for py39 If I open python 39 and do the import clr it works. Is only happening when the import is done from a subprocess. I just thought this can be a good info for you guys. Keep in touch.

2 1

How to run Python in Visual Studio Code? Demo Sample
by hemendra＠theninehertz.com July 12, 2022

July 12, 2022

Hi, I need your assistance how to run Python in Visual Studio Code demo samples. Best Regards, Hemendra Singh | CEO and Co-founder The NineHertz Website: https://theninehertz.com/

1 0

BadImageFormatException or FileNotFoundException- pythonnet and AlphaVSS
by Steven Manross July 11, 2022

July 11, 2022

Howdy all, I am somewhat new to pythonnet and .NET programming, and just joined the mailing list. You have my apologies if I am missing something simple. I am aware that BadImageFormatException suggests that I'm trying to open an x64 DLL on a 32-bit OS or python installation (or vice versa), but neither seem to be the case (that I can tell). Depending on exactly how I call the code, I get a File Not Found or Bad Image Exception. The File Not Found is interesting since the files live in the same directory as a working DLL (AlphaVSS.Common works - built to run on any architecture, AlphaVSS.x64 doesn't). Specifics: * Python 3.9.13 (tags/v3.9.13:6de2ca5, May 17 2022, 16:36:42) [MSC v.1929 64 bit (AMD64)] on win32 * uninstalled Python 3.10 temporarily so I cant get you that detail (sorry) * And the Windows version clearly states it's Windows Server 2016 x64 I'm doing my testing from ipython. The code below was tested with Python 3.9 x64 (pythonnet 2.5.2 via wheel file) and Python 3.10 x64 (installed pythonnet 3.0.0-dev1 from git master a few days ago) on Windows Server 2016 x64 Evaluation patched for current .NET Frameworks 2022-06 and both produce an error on the following code. AlphaVSS DLLs were generated via powershell/nuget, and I just copied the DLLs from my powershellmodules dir to the "clr_dir" below for testing (documentation suggests you copy the files to the same directory for use). This DLL was created for .NET Framework 4.5 and I've installed Framework 4.8 and this Cumulative update: * 2022-06 Cumulative Update for .NET Framework 4.8 for Windows Server 2016 for x64 (KB5014630) This code is eventually intended to manipulate the Volume Shadow Copy Service on Windows. I am aware that there is limited functionality for ShadowCopies from DISKSHADOW and WMI, but wanted to get more functionality from this VSS .NET Library (specifically Shadow Copy Sets), and pythonnet seemed like a great way to implement this code in my favorite scripting language. Here is the documentation for the DLLs (version 2.0.0) if anyone wants that: https://alphavss.alphaleonis.com/api/Alphaleonis.Win32.Vss.html git source: https://github.com/alphaleonis/AlphaVSS I double checked permissions on the DLLs and I have full control as the administrator. UAC is completely turned off on this machine (if it matters). Any suggestions would be appreciated. This is a test system, so I can do just about anything to it including rebuilding it from scratch as it was built specifically for testing this. This is a VM on Hyper-V 2016 (I doubt that matters). Thank you for your time! Steven # ipython dir output In [16]: ! dir "c:\users\administrator\desktop\alphavss" Volume in drive C has no label. Volume Serial Number is 8C70-F8A3 Directory of c:\users\administrator\desktop\alphavss 07/09/2022 03:10 AM <DIR> . 07/09/2022 03:10 AM <DIR> .. 12/03/2019 08:37 PM 69,632 AlphaVSS.Common.dll 12/03/2019 08:37 PM 21,408 AlphaVSS.Common.pdb 12/03/2019 08:37 PM 618,522 AlphaVSS.Common.xml 12/03/2019 08:37 PM 325,120 AlphaVSS.x64.dll 12/03/2019 08:37 PM 271,872 AlphaVSS.x86.dll 12/03/2019 08:29 PM 342,392 Ijwhost.dll 07/09/2022 03:09 AM <DIR> runtimes 07/09/2022 03:10 AM <DIR> win-x64 07/09/2022 03:10 AM <DIR> win-x86 # code import sys import clr import System # from System import Reflection clr_dir = "C:\\Users\\Administrator\\Desktop\\AlphaVSS" if clr_dir not in sys.path: sys.path.append(clr_dir) # common_vss = Reflection.Assembly.LoadFile(f'{clr_dir}\\AlphaVSS.Common.dll') clr.AddReference("AlphaVSS.Common") #pylint:disable=I1101 import Alphaleonis.Win32.Vss as alphavss # clr.AddReference("AlphaVSS.x64") #pylint:disable=I1101 vss = alphavss.VssFactoryProvider.Default # x64_vss = Reflection.Assembly.LoadFile(f'{clr_dir}\\AlphaVSS.x64.dll') # BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) try: factory = vss.GetVssFactory() except System.BadImageFormatException as e: print(f'Bad Image Format: {e}') except OSError as e: # FileNotFoundException: Could not load file or assembly 'AlphaVSS.x64, Version=2.0.0.0, Culture=neutral, PublicKeyToken=959d3993561034e3' or one of its dependencies. The system cannot find the file specified. print(f'File Not Found: {e}')

4 5