Mailman 3 September 2016 - Python.NET

Inheriting from abstract .NET class
by Henning Moeller 18 Aug '17

18 Aug '17

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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PythonNet on Cygwin
by Nikhil Garg 21 Jun '17

21 Jun '17

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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cx_freeze and python.net
by Boris Burdin 22 May '17

22 May '17

Hello everybody, I'm trying to build a python.net application using cx-freeze . Once the application is built, I put in my final folder the Python.Runtime.dll. but it stil doesn't seem to work . Actually, when I run the .exe file, nothing is happening. So, I wonder if there were something else to do, another dll to put in the folder, or any option to use with cx_freeze when building the application ? i would be very grateful if you could help me on this matter .. Thanks in advance, Boris

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pythonnet to drop support for Python 2.6
by Denis Akhiyarov 28 Sep '16

28 Sep '16

We have Travis CI (Linux and OSX soon) for Python 2.6, but no CI for Python 2.6 on Appveyor (Windows). Python 2.6 was dropped by major packages (even numpy is dropping support in v1.12.0) and Python 3.6 is going to be added soon. If anyone is against dropping Python 2.6, then let's collect feedback. https://github.com/pythonnet/pythonnet/issues/270

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call python in Visual C# WinForm application
by solospirit 27 Sep '16

27 Sep '16

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Python for .NET (pythonnet) 2.2.0.dev1 new development release available
by Denis Akhiyarov 22 Sep '16

22 Sep '16

Hello Python and .NET developers, New pythonnet 2.2.0.dev1 version with (pre-)release notes are available for download from PYPI and GitHub: <goog_1064174022> https://pypi.python.org/pypi/pythonnet/2.2.0.dev1 Note that since this is pre-release, use this command for installation: pip install pythonnet --pre -U Detailed release notes: https://github.com/pythonnet/pythonnet/releases News - clrmagic for IPython kernel <https://github.com/pythonnet/clrmagic> - presentation on PyOhio 2016 <https://mail.python.org/pipermail/pythondotnet/2016-September/001810.html> - 3 new pythonnet core developers @denfromufa <https://github.com/denfromufa> @filmor <https://github.com/filmor> @vmuriart <https://github.com/vmuriart> - 26+1 contributors <https://github.com/pythonnet/pythonnet/graphs/contributors> Changelog - Switch to C# 6.0 (#219 <https://github.com/pythonnet/pythonnet/pull/219>) - Relative imports (#219 <https://github.com/pythonnet/pythonnet/pull/219>) - Recursive types (#250 <https://github.com/pythonnet/pythonnet/pull/250> ) - Demo fix - stream reading (#225 <https://github.com/pythonnet/pythonnet/pull/225>) - setup.py improvements for locating build tools (#208 <https://github.com/pythonnet/pythonnet/pull/208>) - unmanaged exports updated (#206 <https://github.com/pythonnet/pythonnet/pull/206>) - Mono update pinned to 4.2.4.4 (#233 <https://github.com/pythonnet/pythonnet/pull/233>) - Documentation update (http://pythonnet.github.io/) - wiki added (https://github.com/pythonnet/pythonnet/wiki) Known Issues - Subclassing .NET classes (#264 <https://github.com/pythonnet/pythonnet/issues/264>) - Mixing python and .NET constructors (#252 <https://github.com/pythonnet/pythonnet/issues/252>) - License update (one blocking contributor @tiran <https://github.com/tiran> out of 27) - Overloading on constructors, ref/out and subtypes (#265 <https://github.com/pythonnet/pythonnet/issues/265>) - pythonhome and pythonpath (#186 <https://github.com/pythonnet/pythonnet/pull/186>) - Regression bug on numpy arrays (#249 <https://github.com/pythonnet/pythonnet/issues/249>)

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powershell + pythonnet = match made by DLR
by Denis Akhiyarov 17 Sep '16

17 Sep '16

Today I came across this simple question about interacting with python from open-sourced *powershell*. It turns out it is so easy to do this using pythonnet! Note that powershell is also heavily using DLR. *http://stackoverflow.com/questions/39183614/how-system-consoleoutputencoding-inputencoding-with-python <http://stackoverflow.com/questions/39183614/how-system-consoleoutputencodin…>* Here is an old thread where using powershell was not possible. https://mail.python.org/pipermail/pythondotnet/2013-May/001371.html

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upcoming talk about pythonnet at PyOhio
by Denis Akhiyarov 14 Sep '16

14 Sep '16

http://pyohio.org/schedule/presentation/240/ Saturday 10:30 a.m.–11:20 a.m.Integrating Python into the CLR with Python for .NETHussein Farran <http://pyohio.org/speaker/profile/269/>Audience level:IntermediateDescription Python for .NET is a project dedicated to being able to call into Python from the CLR. Where IronPython has fallen off as the .NET Python prodigal son Python for .NET has picked up the slack. Python for .NET (or pythonnet for short) is an integration of the C Python engine with .NET. We'll be going through the uses and methods of integration of Python with your .NET projects. Abstract This talk covers embedding Python into the .NET runtime as well as running Python from your .NET code. It will be in C# on the .NET side. It will cover topics such as embedding Python, purposes for scripting, script security, and script/embedded code speeds. I will also cover IronPython and provide a comparison and analysis of how it compares with Python for .NET. This may include talking notes about the implementation of IronPython as well as benchmark comparisons. Hussein Farran Hussein Farran is relatively new to the professional IT world, but he’s doing his best to come in blazing. While building his experience Hussein strives to forge connections with those more experienced and to pass on what he knows to those less experienced. As a Software Developer at UseTech Design, Hussein has the opportunity to dip into many project types and to learn from a varied cast of co-workers and mentors.

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announcement - IPython cell magic for C# usage in jupyter notebooks (clrmagic)
by Denis Akhiyarov 13 Sep '16

13 Sep '16

Last week I noticed very useful blog post on how to use C# magic cells with pythonnet from IPython by Xavier Dupré @sdpython <https://github.com/sdpython>: http://www.xavierdupre.fr/blog/2014-09-20_nojs.html As a result of this, we put together a package clrmagic <https://pypi.python.org/pypi/clrmagic> that can be installed and loaded into jupyter notebooks in 3 steps: *pip install clrmagic* *jupyter notebook* In open notebook enter: *%reload_ext clrmagic* Here is a small demo: %%CS mypower System.dll public static double mypower(double x, double y) { if (y == 0) return 1.0 ; return System.Math.Pow(x,y) ; } <function clrmagic.create_cs_function.<locals>.<lambda>> mypower(3.0,3.0) 27.0 Note that clrmagic works and is tested both on Windows and Linux! It should also work on OSX, but I have not tested. Currently the source code is hosted here: https://github.com/denfromufa/clrmagic I plan to host this code in pythonnet repository under: https://github.com/pythonnet/clrmagic Let's wait for one week to get any feedback from this mailing list and jupyter group (to be posted later this week). Thanks, Denis and Xavier

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cvs -> svn -> git history of Python for .NET
by Denis Akhiyarov 11 Sep '16

11 Sep '16

It happened to me multiple times that the author of particular piece of code was needed to be known. But in the latest pythonnet repository on github we have seem to lost some of this history when transitioning from sourceforge. Are there any git experts, who know how to rebuild the history to include some missing commits? Here is a quick example. Based on a bug report [1] I'm looking at lost history [2] of this C# file in the master branch [3]: [1] https://github.com/pythonnet/pythonnet/issues/262 [2] https://github.com/pythonnet/pythonnet-rawsvnmig/blob/master/pythonnet/src/… [3] https://github.com/pythonnet/pythonnet/blob/master/src/embed_tests/pyimport…

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