Django Admin: let people test a regexp?
My guess is that it would be easiest to do this as a javascript widget--it'll be easier to wedge into the admin and there's tons of examples to work off of.
Daring to venture slightly off of the question though, I'll say I'd be pretty nervous trying to write regexes to parse human-generated responses of any complexity, particularly if the mode of submission will be text messages or other smartphone text. My guess is that typos will ruin your day (though obviously I don't know what kind of data you are collecting).
I'm building a Django app that will let researchers send text messages to study participants and parse the responses. While parsing, say, 'Y/N' and numbers is going to be pretty easy, we'll need to send messages that need more complex responses. Which, I think, means regular expressions.
All this is easy enough; the thing I want to do, however, is let researchers test their regex to see what it does to various responses. So, I'd have a text box with a regex, a text box with a test response, and a button to see what happens.
If I were just building an app, this would again be easy -- is there a way to do this within the confines of the Django admin app?