Getting set up

Installing pybind11

pythonPal uses the header-only library pybind11 to enable the Python/OpenFOAM communication.

We recommend installing pybind11 with Conda. On a *nix system:

conda install −c conda−forge pybind11

Setting up the environment variables

To use the pythonPal, we need to let OpenFOAM know where both pybind11 and the Python interpreter are located in the system.

An easy way to do this is to declare two environment variables, PYBIND11_INC_DIR and PYBIND11_LIB_DIR, whose values are retrieved with the following commands:

export PYBIND11_INC_DIR=$(python3 −m pybind11 −−includes)
export PYBIND11_LIB_DIR=$(python −c 'from distutils import sysconfig; print(sysconfig.get_config_var("LIBDIR"))')

Then, these environment variables must be included in your OpenFOAM code:

• Include PYBIND11_INC_DIR in the EXE_INC field, for example:

EXE_INC = \
 $(PYBIND11 INC DIR)

• Include PYBIND11_LIB_DIR and the Python C dynamic library in the EXE_LIBS field (or in the LIB_LIBS field if compiling a library), for example:

EXE_LIBS = \
 −L$(PYBIND11 LIB DIR) \
 −lpython3.8

Download pythonPal

Finally, download the pythonPal.H file and include it in your OpenFOAM application, as explained in the tutorials.