There are two ways of using Python to run GRASS commands: (or you could mix them together) - Module scripting using the grass python helper library and g.parser. import grass.script as grass For examples see scripts/ in the GRASS 7 source code. - Module creation using hooks into the C library functions using ctypes. The scripts in the doc/python/examples/ directory will describe this. (Ctypes is standard in Python 2.5 and newer; replaces the SWIG implementation in GRASS) More details can be found in the GRASS Programmer's Manual.