Allow regex for contrib.redirects

[Berker Peksag]

It would be really helpful if contrib.redirects would also accept a regex pattern as input.

For example, in ​some cases we want to redirect http://www.python.org/doc/X.Y.X/whatsnew/* to http://www.python.org/release/X.Y.X/whatsnew/*.

I can work on a patch if this seems reasonable.

[Tim Graham]

I think writing regular expressions is better left to developers, in which I think using RedirectView or web server redirects should be sufficient. Feel free to write to the mailing list to get some other opinions.

[Aymeric Augustin]

I had the same initial reaction to this ticket as Tim.

In addition, this would change the interpretation of URLs containing a ., a +, or any other character that has a special meaning in regex. I don't have a good idea to preserve backwards compatibility there.

There's also the question of how we would implement this efficiently. Not all supported databases can anwser "give me the list of rows where field old_path is a regex matching this value.

I think a custom middleware (if you have many patterns) — perhaps a modified version of RedirectFallbackMiddleware — or a RedirectView (if you have a handful of patterns) is the way to go.