I have worked a bit with Python programming for Google App Engine, which I started out in Notepad++ and then recently shifted over to Komodo using two excellent startup tutorials - both of which are conveniently linked from this blog post (direct: here and here).
- Komodo supports the basic
organization of your work into
Projects, which Notepad++ does not
(apart from physical folder
organization).
- The custom commands
toolbar is useful to keep track of
numerous frequently-used commands
and even link to URLs (like online
documentation and the like).
- It has a working (if sometimes clunky)
code-completion mechanism.
In short, it's an IDE which provides all the benefits thereof.
Notepad++ is simpler, much MUCH faster to load, and does support some basic configurable run commands; it's a fine choice if you like doing all your execution and debugging right in the commandline or Python shell. My advice is to try both!