C++ and Python

Hi,

I don't know much about what you want to do, but I do recall
SWIG. Maybe its what your looking for:

http://www.swig.org/

metrix

Yes, you can embed python in your application. The documentation explains how to do it the standard way.

Compiled python modules can be loaded by the embedded python interpreter. There are also functions to execute python source or bytecode from a buffer to allow the code to be stored and used in other ways if you want to use a different method for organizing the embedded code.

Both ways will work, though the recommended approach is to write the program in Python and code modules in C++ as required for performance. You'll see several threads on such matters in the Scripting Languages and Mods forum.

Thanks for replies,

Extending vs Embedding is an interesting topic. However, I couldn't find any valuable information on the net, so I'll just ask this here instead;

Should the application executable be written in C++ or rather pyc modules compiled with py2exe? In the case of py2exe, how can C++ modules be implemented? Also, would it make much sense to have all the C++ code in engine.dll, and let the Python game.exe load it?

Quote:

Original post by CMD ...I couldn't find any valuable information on the net...

Really? I found two excellent links on the first page of a Google search:

http://www.rexx.com/~dkuhlman/python_201/python_201.html#SECTION006000000000000000000
http://twistedmatrix.com/users/glyph/rant/extendit.html

Quote:

Original post by CMD Should the application executable be written in C++ or rather pyc modules compiled with py2exe? In the case of py2exe, how can C++ modules be implemented? Also, would it make much sense to have all the C++ code in engine.dll, and let the Python game.exe load it?

As Kylotan already mentioned, the recommended approach is to write your game in pure Python, then rewrite performance-critical modules in C or C++, or better yet, Pyrex. You can then use py2exe to combine all your modules, regardless of what they were written in, into a single EXE.

- Mike

Extending python = writing python modules in another language

Embedding python = running the python interpreter from within another application

There is actually little to be gained from embedding python, besides the obvious advantage of integrating python with a project that is only using python for certain tasks. The pythonic approach to software development is to use python for everything, writing extensions only where necessary to access other systems or for performance (after it has been decided that the performance of a peice of code cannot be made satisfactory using only python and already existing extensions).

Embedding is also necessary if you want to write your own executable to control the context of the interpreter instead of using py2exe.

Whatever the case of extending or embedding, if you're working on interoperation between c++ and python, you most likely would want to check out Boost.Python if you haven't already. It will ease a lot (all?) of the headache of boxing/unboxing types, keeping reference counts, etc. that otherwise comes with working with the python API.

And to correct the apparently incorrect assumption; Py2exe is not a compiler, and doesn't produce .pyc files. It is merely a packager to allow you to distribute Python files as executables rather than requiring the Python interpreter to be installed.

In the case of extension, how is the game loop and window processing handled in a module?

Python has loops just the same as C++ does! No difference there. By 'window processing', do you mean Windows messages? You'd probably just register the WNDPROC as usual, and that function would call back into Python if required to pass any data that way.

Quote:

Original post by Kylotan Python has loops just the same as C++ does! No difference there. By 'window processing', do you mean Windows messages? You'd probably just register the WNDPROC as usual, and that function would call back into Python if required to pass any data that way.

But how do I handle WinAPI specific functions such as WinMain and MsgProc? AFAIK, HINSTANCE, HRESULT, hWND etc, are unavailable to Python. (Using Boost.Python)

Calling Windows API using ctypes and win32con

I'm fairly sure that, if you download and install win32all and not just win32con you don't need to define the structures yourself, as that example does in the beginning.