Python.NET July 2005

pythonnet@python.org

12 participants
14 discussions

Re: [Python.NET] Trying to constructu a System.IntPtr object
by Mark McMahon 29 Jul '05

29 Jul '05

Hi Brian, Well it seems to work :-) (or at least doesn't give me any errors. Though it seems like Control.FromHandle needs to be in the same process as the control :-( Thanks anyway Mark -----Original Message----- From: Brian Lloyd [mailto:brian@zope.com] Sent: Friday, July 29, 2005 3:38 PM To: Mark McMahon; pythondotnet(a)python.org Subject: RE: [Python.NET] Trying to constructu a System.IntPtr object > I am stumped by this one - googled, even read the Readme!! > > I want to call System.Forms.Control.FromHandle() to get a control from a > handle. But I am getting that handle as Python int instance but > FromHandle requires a System.IntPtr. > > I would have guess that there would be automatic conversion from Python > int to .Net IntPtr. > > >>> CLR.System.IntPtr(23) > Traceback (most recent call last): > File "<stdin>", line 1, in ? > TypeError: 'int' value cannot be converted to System.IntPtr > > So I try converting it to Int32 first... (same for Int64) > ... ooo - you've found a hole in the type conversion logic, methinks. In the interim, you can use the following sneaky hack: from CLR.System import IntPtr, Int32 i = Int32(32) p = IntPtr.op_Explicit(i) # now p is an intptr... Brian Lloyd brian(a)zope.com V.P. Engineering 540.361.1716 Zope Corporation http://www.zope.com

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Trying to constructu a System.IntPtr object
by Mark McMahon 29 Jul '05

29 Jul '05

Hi, I am stumped by this one - googled, even read the Readme!! I want to call System.Forms.Control.FromHandle() to get a control from a handle. But I am getting that handle as Python int instance but FromHandle requires a System.IntPtr. I would have guess that there would be automatic conversion from Python int to .Net IntPtr. >>> CLR.System.IntPtr(23) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: 'int' value cannot be converted to System.IntPtr So I try converting it to Int32 first... (same for Int64) >>> CLR.System.IntPtr(CLR.System.Int32(23)) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: value cannot be converted to System.IntPtr So now I am stuck - any help appreciated, Thanks Mark

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sys.stderr and embedded python
by Guy Robinson 28 Jul '05

28 Jul '05

Hi, I have python for .NET embedded in my application and I'm trying to catch any sys.stderr output. If I run the script with the sys.stderr handler from the python commandline it works. If I run the script from the parent application it doesn't run my stderr handler. It seems to bypass it. Both my sys.stdout handler and sys.exitfunc work both from the commandline and the application. It's only sys.stderr that doesn't. What am I missing? Guy

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IP & Python for .NET 2.0 roadmap
by Brian Lloyd 25 Jul '05

25 Jul '05

Hi all - sorry to cross-post to the IP list, but I know there are some folks who follow both projects and might want a head's up -- please post any replies to the pythondotnet list unless it really is pertinent to IP per se. I'm about to wrap up development on Python for .NET and make a 1.0 release, and wanted to post a roadmap for 2.0. The next (and hopefully last) RC release of 1.0 will include a few changes to make out/ref param behavior compatible with IronPython, followed by a final 1.0 release. The Roadmap: Python for .NET 1.x will be targeted to the .NET 1.x runtime. It will not be terribly compatible with any code developed for IronPython. Python for .NET 2.x will be targeted to the .NET 2.x runtime, and Python code for it will be as compatible as possible with the IronPython runtime. Meaning, I hope that Python code that runs on pythonnet 2.x will run without changes on IronPython. Generally, I think all of us are excited to see the sustained effort being applied to IronPython. Having a code-compatible 'CLR consumer' implementation based on CPython should be helpful not only in providing an upgrade path for the future for users of pythonnet but also provide some interesting possibilities for comparative conformance and performance testing, test sharing, etc. Proposed changes for 2.0 (mostly related to IP compatibility): - Support for 'son of sys.LoadAssemblyByName' As noted on the IP mailing list, Jim doesn't like the current sys.LoadAssemblyByName solution (http://lists.ironpython.com/pipermail/users-ironpython.com/2005-July/000805 .html) I mostly tend to agree - at any rate, I'd like for pythonnet to support whatever the successor is. (Some suggestions maybe in another thread) - API compatibility with the IP PythonEngine I'd like the pythonnet PythonEngine to support the API of the IP engine, to make it at least possible to swap back and forth with a minimum of effort. The current pythonnet PythonEngine API would be deprecated (but available) until 3.0. A probable breaking change here is that pythonnet requires managed code to be aware of the GIL -- IP seems to have gotten rid of that requirement (hooray!). The gist is that it would be nice if embedders writing in C#, VB or other less-dynamic managed code could swap back and forth with no more than some namespace futzing if possible. - Support syntax for resolution of generic types, methods and overload resolution IP has (or soon will have) introduced some spelling to support instantiation of generic types and fine resolution of overloaded methods. It should be no problem to support the spellings that have so far been proposed: # instantiate a generic type from System.Collections.Generic import List x = List[str]() # realized generic type as first class object c = List[str] # open generic types as objects -- not sure yet how this would # or wouldn't relate to IP plans o = List <open type 'List' ...> # pinpoint overloads -- note that we would allow the use of # python types to indicate CLR types in these limited cases # a la IP (str == System.String, int == System.Int32, etc.) Console.WriteLine[str]("Hi") Console.WriteLine[int](6) - Leverage LCG in the runtime There are a few places that could benefit from LCG -- this is a 'nice to have', since we'll already benefit from some of the CLR 2.x improvements to caching of reflected members, etc. - Import spelling This is probably the most controversial and potentially breaking change for users of Python for .NET 1.x. PythonNet currently uses a top level 'CLR' module to contain all modules (namespaces) imported from the CLR. For 2.x, I would propose killing this in favor of the the direct spelling used by IP (import System.Console vs. import CLR.System.Console). This will have some effect on performance, but I think it will be \ manageable. If at all possible, I'd like to arrange for the CLR.xxx spelling to remain supported (but deprecated) until 3.0, unless it would really kill perf. Note that all of these changes are focused on the 'CLR consumer' aspect of Python. I don't know of any public designs for IP as a CLR producer (and having CPython act as a producer introduces a whole new world of problems), so at this point I'm only looking at compatibility from a consumer perspective. generic-'ly, Brian Lloyd brian(a)zope.com V.P. Engineering 540.361.1716 Zope Corporation http://www.zope.com

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Subset implementation for CompactFramework
by Shane Holloway (IEEE) 25 Jul '05

25 Jul '05

I was wondering if I could get some insight into how much of the Python for .NET framework could be ported to the Compact Framework? Python is still my language of choice, and it would be wonderful to use it to develop on the PocketPC. This framework seems to be the ideal interop layer to help me do this effectively. Currently we have two separable goals. First is to be able to use python libraries from VB or C# on the PocketPC. Second is to be able to use WindowsForms exclusively from python. In my investigation, I worked through compiling pythonnet for the compact framework, and found a heavy dependence on system.reflection.emit, which is not available on the Compact Framework. (Which makes me grumpy, but that's another matter ;) This brings me to the question of how much of pythonnet is dependent on system.reflection.emit? Can we achieve either of the above goals? If it is possible, I'd love to help move this forward for the crippled Compact Framework. In this case, I'd like to talk with someone to get an overview of the architecture. Thanks! -Shane Holloway

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Strong name in python.runtime.dll
by Rencelj Marco 20 Jul '05

20 Jul '05

I'm trying to integrate pythonnet into a solution that requires strong named dll. Does anybody know how to add strong names rebuilding the python.runtime.dll? Thank's in advance ... Marco Rencelj

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Is it possible to access the C# keywords?
by T Barket 17 Jul '05

17 Jul '05

Hello, First off, python for .net is a great tool. Tks vm, Brian. My question is, I cant figure out how to access the C# keywords. Is that possible? For instance, on the python side, I want to do something like this C# snippet: Type type = typeof(One_Of_My_CSharp_Classes); MemberInfo[] member_info = type.GetFields(); But I cant figure out how to access the C# keyword "typeof". Neither CLR.typeof nor CLR.System.typeof works. Is there a way to do this? Tks vm, Tom

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2 ? about embedding python
by Guy Robinson 16 Jul '05

16 Jul '05

Hello, Both questions relate to python embedded in a C# application. 1.. If my python script returns a False/True then to pass the bool to the c# script then this: bool result = (bool)runFrm.AsManagedObject(typeof(Boolean)); should work shouldn't it? 2.. If the python script needed to return 3 values(2 strings + 1 boolean), then how do I pass these to the C# application. I can't return an array because the values aren't all the same type. And I can see no equivalent of a python tuple. TIA, Guy

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Windows Forms design...
by Alex Mohr 10 Jul '05

10 Jul '05

Hi Folks, I'm new to Python for .NET and I'm wondering what methods folks are using for creating Windows Forms apps with Python. Is there a nice way to use the forms designer in Visual Studio .NET with Python? Or are people just creating forms directly in code? I tried googling around for this but couldn't find much. Thanks, Alex

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Newbie question
by Philippe C. Martin 08 Jul '05

08 Jul '05

Hi, I am new to this list and .NET. From the quick reading I've done, I understand pythondotnet can help me "package" my Python libraries (they use a few C extensions) so they look like .NET components to the W. world. Am I correct ? Regards, Philippe -- ************************************* Philippe C. Martin SnakeCard, LLC www.snakecard.com +1 405 694 8098 *************************************

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Python.NET July 2005