Compilerpython.vim is a project mainly written in Vim Script, it's free.
compiler plugin for python
This is a mirror of http://www.vim.org/scripts/script.php?script_id=1439
Based on the script and notation from vimscript #477
This compiler script does not run the source through the python interpreter, but instead uses the py_compile package to check for syntax errors. This allows for a development cycle similar to a compiled language - edit, compile, run.