One thing that doesnt receive enough attention is the changes to the Python C-api. References : 1) http://python3porting.com/cextensions.html http://python3por

One thing that doesnt receive enough attention is the changes to the Python C-api. References : 1) http://python3porting.com/cextensions.html http://python3porting.com/cextensions.html 2) http://docs.python.org/3.0/whatsnew/3.0.html#build-and-c-api-changes http://docs.python.org/3.0/whatsnew/3.0.html#build-and-c-api... In the scientific computing world C extensions are used everywhere and moving Python 2.x c extensions to Python 3 is a significant roadblock.