Mailman 3 June 2017 - 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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.NET Core support
by Mark Traudt Sept. 14, 2017

Sept. 14, 2017

I see there is a project for .NET Core at https://github.com/pythonnet/pythonnet/projects/2 but it is empty. Is there any work being done on this? If not, would you accept a pull request if somebody wanted to help? Mark Traudt | Chief Technology Officer Quantifi Inc. 17 Union Pl | Floor 2 | Summit | New Jersey | 07901 Tel: +1 (908) 273-9455 [https://www.quantifisolutions.com/Data/Sites/1/media/emailsignature/horizon…]<https://www.quantifisolutions.com> [https://www.quantifisolutions.com/Data/Sites/1/media/emailsignature/web_ema…]<https://www.quantifisolutions.com> [https://www.quantifisolutions.com/Data/Sites/1/media/emailsignature/twitter…] <https://twitter.com/quantifi> [https://www.quantifisolutions.com/Data/Sites/1/media/emailsignature/linkedi…] <https://www.linkedin.com/company/quantifi-inc-> [https://www.quantifisolutions.com/Data/Sites/1/media/emailsignature/google_…] <https://plus.google.com/+Quantifisolutions-software> Notice: This email message, together with any attachments, contains information of Quantifi, Inc. (Summit, NJ, USA) that may be confidential, proprietary, copyrighted, and/or legally privileged, and is intended solely for the use of the individual or entity named in this message. If you are not the intended recipient, and have received this message in error, please immediately return this by email and then delete it.

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Inheriting from abstract .NET class
by Henning Moeller Aug. 18, 2017

Aug. 18, 2017

Hello out there, I'm trying to inherit from an abstract .NET base class in Python (2.7). I'm a Python n00b but from what I understood... Here's what I managed to do in Python only and which works fine: [File: room.py] ------- import abc class Room(object): def __init__(self, door): self.door = door def open(self): self.door.open() def close(self): self.door.close() def is_open(self): return self.door.is_open() class Door(object): __metaclass__ = abc.ABCMeta def open(self): if not self.is_open(): self.toggle() def close(self): if self.is_open(): self.toggle() @abc.abstractmethod def is_open(self): pass @abc.abstractmethod def toggle(self): pass class StringDoor(Door): def __init__(self): self.status = "closed" def is_open(self): return self.status == "open" def toggle(self): if self.status == "open": self.status = "closed" else: self.status = "open" class BooleanDoor(Door): def __init__(self): self.status = True def is_open(self): return self.status def toggle(self): self.status = not (self.status) Door.register(StringDoor) Door.register(BooleanDoor) ------- Now, all I did was to replace the abstract base class Door by a C# representation: [File: PythonAbstractBaseClass.dll] ------- namespace PythonAbstractBaseClass { public abstract class Door { public virtual void Open() { if (!IsOpen()) Toggle(); } public virtual void Close() { if (IsOpen()) Toggle(); } public abstract bool IsOpen(); public abstract void Toggle(); } } ------- Removing Door from the Python part and importing it from the .NET assembly instead, I end up with this: [File: room2.py] ------- import clr import abc from PythonAbstractBaseClass import Door class Room(object): def __init__(self, door): self.door = door def open(self): self.door.open() def close(self): self.door.close() def is_open(self): return self.door.is_open() class StringDoor(Door): def __init__(self): self.status = "closed" def is_open(self): return self.status == "open" def toggle(self): if self.status == "open": self.status = "closed" else: self.status = "open" class BooleanDoor(Door): def __init__(self): self.status = True def is_open(self): return self.status def toggle(self): self.status = not (self.status) Door.register(StringDoor) Door.register(BooleanDoor) ------- But this fails with the following error message: Door.register(StringDoor) AttributeError: type object 'Door' has no attribute 'register' >From what I understood about abc.ABCMeta, this metaclass contributes the 'register' method. It seems that abstract C# classes do not come with the same metaclass. They instead come with metaclass "CLR Metatype" which obviously does not provide 'register'. But if I drop the call to 'register', on instantiating one of the derived classes, I receive the error message sdoor = StringDoor() TypeError: cannot instantiate abstract class Is there a way to inherit from an abstract .NET class or is this is missing feature? Thanks in advance, Henning

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PyScope in Python.NET
by WARD Steve June 27, 2017

June 27, 2017

Hi Denis, I've had to stop development for now because PyScope global variables don't seem to be working in similar fashion to IronPython. I want a global variable assigned at start-up with PyScope.Set(name,value), where value is most likely a .NET object, to be available later on in any module I might import. I could try things out with the NUnit testing framework in the pythonnet solution but the tests are not listed in Visual Studio for some reason. Steve ___________________________________________________________________________This e-mail is confidential and is for the addressee only. Please refer to www.oxinst.com/email-statement for regulatory information.

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PyScope
by WARD Steve June 27, 2017

June 27, 2017

Hi, I'm keen to use the PyScope class as I'm working to replace an IronPython interactive scripting environment in a .NET application. I read about this feature here: https://github.com/pythonnet/pythonnet/pull/381 Is this due for release soon, and is there an alternative way to create something similar to a scope with the current release 2.3.0? Thanks Steve Ward Steve Ward Senior Software Engineer Oxford Instruments ___________________________________________________________________________This e-mail is confidential and is for the addressee only. Please refer to www.oxinst.com/email-statement for regulatory information.

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Issue not finding Assembly
by A M June 21, 2017

June 21, 2017

Hello, I'm using ironpython for a while to operate a .dll library. This works, but I need to use some CPython libraries so I would like to try to integrate de .dll in python 2.7 I installed pythonnet through > pip install pythonnet (Windows 7) installing pythonnet-2.3.0-cp27-cp27m-win_amd64.whl I proceeded like in ironpython: import clr import sys sys.path.append("C:/Program Files (x86)/DHI/2016/bin/") clr.AddReference('DHI.Tornado.NET') import TornadoNET and meanwhile in ironpython it works, in using python with pythonnet I get: File "Automated.py", line 32, in <module> clr.AddReference('DHI.Tornado.NET') System.IO.FileNotFoundException: Unable to find assembly 'DHI.Tornado.NET'. at Python.Runtime.CLRModule.AddReference(String Name) DHI.Tornado.NET is a .net 4.0 I read everything I could on previous similar issues, but I haven't been able to solve it. Someone has an idea? Best regards

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PythonNet on Cygwin
by Nikhil Garg June 21, 2017

June 21, 2017

Hi Guys, I was wondering if anyone knows how to make Python for .Net work on cygwin installation of python. I have been looking around and find a mixed bag of information. If anyone knows of the working version of Python for .Net and its dependency, I would appreciate if you could share it with me. Currently, I am using a generic windows version and it works just fine, but I need it to work on Cygwin version of python. I appreciate any helpful replies. Thanks, Nikhil

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PyData Seattle, Microsoft - Python for .NET or .NET for Python Denis Akhiyarov, Xavier Dupré
by Denis Akhiyarov June 9, 2017

June 9, 2017

https://pydata.org/seattle2017/schedule/presentation/61/ Python for .NET or .NET for Python Denis Akhiyarov, Xavier Dupré Audience level: Intermediate Description For long time .NET developers wanted to tap into the rich libraries from SciPy and PyData communities. Bridging .NET and CPython runtimes is the easiest approach to solving this problem! Python for .NET (pythonnet, Python.NET) makes this possible by wrapping CPython C-API from C# in .NET and Mono runtimes. This also allows two-way inter-operability between both runtimes on Windows, Linux, and OSX. Abstract For long time .NET developers wanted to tap into the rich libraries from SciPy and PyData communities. Bridging .NET and CPython runtimes is the easiest approach to solving this problem. Python for .NET (pythonnet, Python.NET) makes this possible by wrapping CPython C-API from C# in .NET and Mono runtimes. This also allows two-way interoperability between both runtimes on Windows, Linux, and OSX (MacOS), and even Linux subsystem on Windows! This presentation is going to show how to use Python code from .NET and .NET assemblies from Python. Particular importance in Python.NET is given to installation options: Python wheels, conda and nuget binaries, docker images, and even distribution with WinPython. The deployment is also simplified with tools such as PyInstaller and cx_freeze. This presentation will show how to install and deploy Python.NET apps using these tools. In this talk we are going to show how to call numpy, scipy, pandas, matplotlib, sympy, and pyomo from .NET without much boilerplate code. The second part will show how to use .NET from Python, particularly C# magic cells (clrmagic) in ipython kernel with Jupyter Notebooks. The Python.NET tutorial was converted to Jupyter Notebook and C# code cells that are embedded within the same notebook. This presentation will show few demos with REPL experience both from C# and Python using IPython, scriptcs, and Visual Studio. All libraries used in this presentation are open-source and available on all major platforms. Python for .NET is a library developed since 2003, which "graduated" from Zope, moved to SourceForge and eventually to GitHub, where it became widely used and adopted. This talk will also demonstrate clrmagic - Jupyter extension, built on top of pythonnet and developed by authors of this presentation. Python.NET is built with a number of open-source technologies. It uses pycparser, ply, and clang (gcc and MSVC also work) for parsing internal CPython structures. .NET types are exposed to Python with Unmanaged Exports (DllExport) open-source "compiler" on Windows. On other platforms, C-API of Mono and CPython are used to "bootstrap" both runtimes. Python.NET is used by financial algorithmic trading platforms, engineering companies, and few open-source projects: QuantConnect Lean, pywebview, Pybee Beeware Toga cross-platform UI toolkit. Python.NET enables large .NET applications to embed numerical Python libraries without boilerplate code and without sacrificing for performance.

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Python for .NET - At Microsoft Houston
by Denis Akhiyarov June 8, 2017

June 8, 2017

Python for .NET location: At Microsoft Houston - Town & Country Thursday, June 08, 2017 6:30 PM - 8:30 PM http://hdnug.org/events_view.aspx?eventid=137

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