Why you want to use phyton packages? Is there really a need to do it? To install in haiku you can use haiku packages.
The haiku packages can install all included files to the right position (write protected areas too). Phyton packages could get problems here.
If you want to create packages out of git, you can try my package creator: www.software.besly.de
http://old.besly.de/menu/search/archiv/sys/hpkg-creator_eng.html