Python C++

[Helmut Jarausch]

Neal D. Becker wrote:
> Helmut Jarausch wrote:
> 
> 
>>Francois Fernandes wrote:
>>
>>>Hi!
>>>
>>>Is it possible to easyly integrate c++ classes in python?
>>>
>>>I don't want to use boost c++.
>>>
>>>Does anyone know how to start or where to find documentation for this?
>>>
>>
>>I prefer  PyCXX  http://cxx.sourceforge.net
>>
>>
> 
> 
> Looks interesting.  I want to expose lots of signal processing algorithms
> written in C++ to python.  I want to use std::vector for containers,
> because they are fast.  I need to create python types for
> std::vector<double> and std::vector<std::complex<double>> at minimum.  The
> Python interface doesn't need to know much about these types, just be able
> to create vectors of a given size.
> 
> Would PyCXX be a good choice for this?  Are there any samples of code
> similar to this?
> 

I think, yes. PyCXX allows for use of the STL.
For each type FOO in your module you provide a new_FOO which is called when you
create an object. There you can call any C++ code including class constructors.
PyCXX helps you in filling out these long structs needed for a new type.
It helps with exception handling and reference counting.
I am new to PyCXX myself, but it worked very soon. There is a rather general
example in the Demo directory. I've just copied and modified the code and it
worked like expected - GREAT!  The documentation is not too long but suffucient
and very readable. It does NOT (try to) wrap your C++ classes automatically like
other tools. I prefer this (since I don't have hundreds of classes). One can
easily fully understand what's going on and if something is missing (e.g. I think
conversion of an unsigned int to a Python long int) one can easily add this
feature using calls from the C-API himself.


-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany