I'm assuming that FOS = "free open source"... In any case, what operating system do you run? If you're on OS X, I highly recommend TextMate. It's not free, but it has good support (either via built-in or third-party plugins) for Python as well as HTML, SQL, XML, Django templates, and the like. A lot of Rails folks use it (as well as Django and TurboGears developers, I might add).
The best general-purpose IDE for Python, IMO, is WingIDE. Again, it's not free (personal license will cost you $30). It runs on each of the major platforms - Windows, Linux, OS X - and has some nice features, including code completion, syntax highlighting, a built-in Python shell, etc. I don't think it has any features built-in specifically for web dev, however; if you have to do lots of HTML, XML, and SQL as part of your project, you might want something a bit more general-purpose. If you're determined to go the FOSS route, you can always use VIM, Emacs, Eric, or SPE. Just my two cents... --dave -- http://mail.python.org/mailman/listinfo/python-list
