Super simple "sandbox". The sandbox will run any code in "code.in" and will read in the contents of "data.in" as a string. Alternatively, you can specify your own files as arguments by typing:
python sandbox.py code data
Leave those options empty to run the test code.
The sandbox is just python with its namespace cleared. Most of the pre-defined data types still work but import, open and most other built in functions are gone.