VIM Quicky: set tabs and spaces behaviour for different files

Never really bothered me before, because I only used Python and C, so I always replaces tabs with spaces.
However, with more C programming lately, I needed to start working with Makefiles. These require tabs instead of spaces.
So here is how to. In the end of my .vimrc file I put:

" python python pyhton
" convert tabs to spaces before writing python files or C files
autocmd! bufwritepre *.py,*.c,*.h set expandtab | retab! 4

" convert spaces to tabs when reading python file or C files
autocmd! bufreadpost *.py,*.c,*.h set noexpandtab | retab! 4

Et viola, not so complicated!