I currently work with .NET exclusively and would like to have a go at python. To this end I need to set up a python development environment. I guide to this would be handy. I guess I would be doing web development so will need a web server and probably a database. I also need pointers to popular ORM's, an MVC framework, and a testing library.
One of my main criteria with all this is that I want to understand how it works, and I want it to be as isolated as possible. This is important as i am wary of polluting what is a working .NET environment with 3rd party web and database servers. I am perfectly happy using SQLite to start with if this is possible.
If I get on well with this I am also likely to want to set up automated build and ci server (On a virtual machine, probably ubuntu). Any suggestions for these would be useful.
My ultimate aim if i like python is to have similar sorts of tools that i have available with .NET and to really understand the build and deployment of it all. To start with I will settle for a simple development environment that is as isolated as possible and will be easy to remove if I don't like it. I don't want to use IronPython as I want the full experience of developing a python solution using the tools and frameworks that are generally used.
It's not that hard to set up a Python environment, and I've never had it muck up my .NET work. Basically, install Python --- I'd use 2.6 rather than 3.0, which is not yet broadly accepted --- and add it to your PATH, and you're ready to go with the language. I wouldn't recommend using a Ubuntu VM as your development environment; if you're working on Windows, you might as well develop on Windows, and I've had no significant problems doing so. I go back and forth from Windows to Linux with no trouble.
If you have an editor that you're comfortable with that has basic support for Python, I'd stick with it. If not, I've found Geany to be a nice, light, easy-to-use editor with good Python support, though I use Emacs myself because I know it; other people like SCITE, NotePad++, or any of a slew of others. I'd avoid fancy IDEs for Python, because they don't match the character of the language, and I wouldn't bother with IDLE (included with Python), because it's a royal pain to use.
Suggestions for libraries and frameworks:
Good luck, and welcome to a really fun language!
EDIT summary: I originally recommended Karrigell, but can't any more: since the 3.0 release, it's been continuously broken, and the community is not large enough to solve the problems. CherryPy is a good substitute if you like a light, simple framework that doesn't get in your way, so I've changed the above to suggest it instead.