http://diveintopython.org/file_handling/index.html
really good tutorial on exceptions. The whole book is well done, in fact, I recommend it. I also like Practical Python, and the Oreilly "Learning Python", but they're not online. For production purposes, you'd still do date-check on the client (javascript) but you must do the check server-side nevertheless. -- http://mail.python.org/mailman/listinfo/python-list
