Python as a glue

Python is often considered as a glue to combine different programming languages under one hood. Why should one combine different languages? There are some good reasons if there are existing libraries that should be combined or to increase the performance. Python is relatively fast if compared to Matlab or IDL but optimized Fortran code can be much faster. However, before spending time in optimization one should think if it is really necessary.. See http://www.acm.org/ubiquity/views/v7i24_fallacy.html

The normal Python interpreter, or sometimes called cPython, is build in the C programming language. Python can be extended with C-routines and Python objects can be called from C. See http://docs.python.org/c-api/ for more information. The Jython interpreter is a Java version of Python which allows interactive and dynamic Java programming.

Using Fortran Subroutines in Python

F2PY: Fortran to Python interface generator

Calling Fortran code from python is easy! Create a file hello.f:

C File hello.f
      subroutine foo (a)
      integer a
      print*, "Hello from Fortran!"
      print*, "a=",a
      end

Run f2py -c -m hello hello.f

Now in IPython try:

In [1]: import hello
In [2]: hello.foo(4)
 Hello from Fortran!
 a=           4

Example taken from

F2PY: Fortran to Python interface generator