Combining Python with Fortran, C, and C++

Most languages offer the possibility to call code written in other languages, but in Python this is a particularly simple and smooth process. One reason is that Python was initially designed for being integrated with C and extended with new C code. The support for C implicitly provides support for closely related languages like Fortran and C++. Another reason is that tools, such as F2PY and SWIG, have been developed in recent years to assist the integration and, in simpler cases, fully automate it. The present chapter is a first introduction to mixed language programming with Python, Fortran 77 (F77), C, and C++. The focus is on applying the tools F2PY and SWIG to automate the integration process.

Chapter 5.1.2 gives an introduction to the nature of mixed language programming. Chapter 5.2 applies a simple Scientific Hello World example to demonstrate how to call F77, C, and C++ from Python. The F77 simulator from Chapter 2.3 can be equipped with a Python interface. A case study on how to perform this integration of Python and F77 is presented in Chapter 5.3.

In scientific computing we often invoke compiled languages to perform numerical operations on large array structures. This topic is treated in detail in Chapters 9 and 10.

Readers interested in Python-Fortran integration only may skip reading the C and C++ material in Chapters 5.2.2 and 5.2.3. Conversely, those who want to avoid the Fortran material may skip Chapters 5.2.1 and 5.3.