[Python.NET] Could you tell me how to call python from c#?

[Karpenstein, Nissim (C-BASS)]

PyObject has a GetItem method that takes a string or an int to access
the elements in a dictionary or a list.  You can use GetAttr to get the
attributes of a PyObject.  Check out the PyObject class in the class
browser to see the rest of the functionality.  I think that you can set
the PYTHONPATH through .net using system.environment or through PYTHON
using sys.path.   

> -----Original Message-----
> From: Barrett, Joey [mailto:Joey.Barrett at itg.com] 
> Sent: Wednesday, June 06, 2007 12:22 PM
> To: Karpenstein, Nissim (C-BASS); pythondotnet at python.org
> Subject: RE: [Python.NET] Could you tell me how to call 
> python from c#?
> 
> 
> Thank you for your response, this is helpful.
> 
> The methods called usually return lists or dictionaries and 
> sometimes other types too that need to be used within the C#. 
>  In the example you provided the return value from 
> InvokeMethod(), is a string "fromPython", but I noticed 
> InvokeMethod() actually returns a PyObject.
> 
> How can I look at that PyObject and extract the returned values?
> 
> The classes I use import many modules from a number of 
> locations on disk that aren't known to the interpreter.
> 
> Is there a way to add to the PYTHONPATH programmatically in 
> C# using the Python for .net library, or would it be required 
> to write a wrapper python module that adds to the path first? 
>  Maybe there is another way to handle this?
> 
> Thank you again
> 
> Joey J. Barrett
> Investment Technology Group, Inc.
> 
> -----Original Message-----
> From: Karpenstein, Nissim (C-BASS)
> [mailto:Nissim.Karpenstein at C-BASS.COM]
> Sent: Wednesday, June 06, 2007 6:37 AM
> To: Barrett, Joey; pythondotnet at python.org
> Subject: RE: [Python.NET] Could you tell me how to call 
> python from c#?
> 
> I tried to post this to the list yesterday but it bounced 
> because of address issues...hopefully this will work:
>  
> If you want to execute a python program from c-sharp you can 
> just use System.Diagnostics.Process to execute python.exe and 
> you don't need python for .net.
> 
> Python for .net is more appropriate for if you want to 
> execute a python function or create an instance of a python 
> object and then run methods and access attributes from your 
> C# program.
> 
> The example you linked to is OK, except that he modified the 
> Python.Runtime.Dll which is not necessary.
> 
> If you had a Hello.py with a function called hello Like this:
> 
> def hello():
>     return 'hello'
> 
> 
> You could do this in C#:
> 
> PythonEngine.Initialize();
> PyObject helloModule = PythonEngine.ImportModule("Hello");
> String fromPython = helloModule.InvokeMethod("hello", new 
> PyTuple()).ToString(); PythonEngine.Shutdown();
> 
> // now fromPython = "hello"
> 
> If your function takes an argument:
> 
> def returnArg(arg):
>     return arg
> 
> PythonEngine.Initialize();
> PyObject helloModule = PythonEngine.ImportModule("Hello");
> String fromPython = helloModule.InvokeMethod("returnArg", new 
> PyObject[1] {new PyString("Test")}).ToString(); 
> PythonEngine.Shutdown();
> 
> // now fromPython = "test"
> 
> ________________________________
> 
> 	From: pythondotnet-bounces at python.org
> [mailto:pythondotnet-bounces at python.org] On Behalf Of Barrett, Joey
> 	Sent: Tuesday, June 05, 2007 8:11 PM
> 	To: pythondotnet at python.org
> 	Subject: Re: [Python.NET] Could you tell me how to call 
> python from c#?
> 	
> 	
> 
> 	Hi,
> 
> 	 
> 
> 	I also would be very interested in seeing some examples 
> to "call python from c#" using "Python for .NET".  I have dug 
> around Google and a number of forums---I can't find anything 
> except the post from below.  I really hope I'm not missing 
> the obvious somewhere.
> 
> 	 
> 
> 	IronPython is great but my needs require using a few 
> c++ extensions compiled for CPython (that can't be recompiled).
> 
> 	 
> 
> 	Also thanks in advance,
> 
> 	 
> 
> 	Joey J. Barrett
> 
> 	Investment Technology Group, Inc.
> 
> 	 
> 
> 	 
> 
> 	 
> 
> 	 
> 
> 	Hello, PythonNet!
> 
> 	 
> 	I'm looking for some sample code to call python from C#.
> 	Actually, I'd like to execute python program(let say 
> 'Hello.py') from C# 
> 	with parameters.
> 	Actually, I'm a newbie at both of languages. So, could 
> you give sample 
> 	source code? I was looking for some guide or source for 
> several days, 
> 	but I couldn't find it. What I've got so far from googling is 
> 	
> http://mail.python.org/pipermail/pythondotnet/2003-November/00
> 0037.html,
> 
> 	but I can't understand it and old one.
> 	 
> 	Thank you in advance.
> 	Seungweon.
> 
> 	 
> 
> 	 
> 
> 	
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> It is not intended as an offer or solicitation for the 
> purchase or sale of any financial instrument or as an 
> official confirmation of any transaction. Moreover, this 
> material should not be construed to contain any 
> recommendation regarding, or opinion concerning, any 
> security. It may contain confidential, proprietary or legally 
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> Securities products and services provided to Canadian 
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