Pycerberus is a framework to check user data thoroughly so that you can
protect your application from malicious (or just garbled) input data.

 * Remove stupid code which converts input values: After values are
   validated, you can work with real Python types instead of strings -
   e.g. 42 instead of '42', convert database IDs to model objects
   transparently.
 * Implement custom validation rules: Writing custom validators is
   straightforward, everything is well documented and pycerberus only
   uses very little Python magic.
 * Focus on your value-adding application code: Save time by
   implementing every input validation rule only once, but 100% right
   instead of implementing a dozen different half-baked solutions.
 * Ready for global business: i18n support (based on GNU gettext) is
   built in, adding custom translations is easy.
 * Tune it for your needs: You can implement custom behavior in your
   validators, e.g. fetch translations from a database instead of using
   gettext or define custom translations for built-in validators.
 * Use it wherever you like: pycerberus is used in a SMTP server, trac
   macros as well as web applications - there are no dependecies on a
   specific context like web development.

WWW: http://www.schwarz.eu/opensource/projects/pycerberus