tayral / cpp2py

C++ to python wrapper based on clang

  ALPHA: BEING TESTED

Cpp2Py is the Python-C++ interfacing tool of the TRIQS project, provided here as a standalone project. (The TRIQS website is under http://ipht.cea.fr/triqs. Start there to learn about TRIQS.)

Installation

To install Cpp2Py, follow the installation steps:

git clone  https://github.com/TRIQS/cpp2py.git cpp2py
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX=INSTALL_DIR ../cpp2py
make && make install

This installs the library in INSTALL_DIR. You should now update your PYTHONPATH to make it available to the python interpreter:

export PYTHONPATH=INSTALL_DIR/lib/python2.7/site-packages:$PYTHONPATH

Example

Suppose you have created a c++ source file mymodule.hpp in a folder SRC:

///A wonderful little class
class myclass{
	int a,b;

	public:
		myclass(int a_, int b_):a(a_),b(b_){}

	///getter for member a
	int get_a() const { return a;} 
};

In the same folder, create a file CMakeLists.txt:

cmake_minimum_required(VERSION 3.5)
find_package(Cpp2Py REQUIRED)

set(CPP2PY_ADD_MODULE_ADDITIONAL_PYTHONPATH "INSTALL_DIR/lib/python2.7/site-packages/")

include_directories(${Cpp2Py_DIR}/../../include)
include_directories(.)

add_cpp2py_module(mymodule)

Then, in the SRC folder, issue the command

INSTALL_DIR/bin/c++2py mymodule.hpp 

This creates a file mymodule_desc.py.

Exit the SRC folder and create a BUILD folder. Then, issue the following commands:

cd BUILD
cmake -DCMAKE_PREFIX_PATH=INSTALL_DIR/share/cmake/ ../SRC
make 

In the BUILD dir, you should see a mymodule.so file. You can now use your c++ class in Python:

import mymodule
A = mymodule.Myclass(4,5)
A.get_a() #outputs 4

By convention, c++ classes of the type my_little_class are converted in python classes of the type MyLittleClass.

License

Before you proceed, make sure you have read the LICENSE.txt file.

Enjoy!

The TRIQS team