I managed to port one of my libraries that I made way back from perl to python, the experience was quite interesting, although very tiring. I don’t think I can recommend perl again since the python just looks so much cleaner and there were whole sections I could remove because they were handled by python.
If your interested in data validation check out lp:~doctormo/doctormo-random/xsdvalidate and have a look at the tests, it’s basically a module similar to the existing xml.xsd but with a focus on python structures.
Because it’s a library few of you are going to know how to run the tests and have a dig around at what it can do. For those in the know, it’s got a structural error reporting mechanism which allows the code to know what failed to validate. In perl I was using this module hooked up to a django like framework which would be able to check if the form information was valid and which fields failed and how, this information was actually fed directly back to the template for human warnings so the entire process was automated to a frightening degree, you really didn’t need any code for most transactions.
I have a test suite but I could always do with more tests, if you find something it’s not covering let me know.