A large list of editors supporting Python can be found at http://www.python.org/editors/
ConText
I use a freeware text editor called ConText (for windoze only I'm afraid) from http://www.fixedsys.com/context/.
It includes language highlighters for a lot of languages including python. It also allows customisation to execute a command using the loaded files (e.g. execute the loaded python script) then capture the output and decod the line numbers where the problem occurred.
Dave Moor
jEdit
A nice Swing based editor for many languages and Java specially. You can add additional plugins like PyUtil and Jython for your Python work. Get it from http://jedit.org
Ashish Shrestha [http://www.nyatapol.com.np Nyatapol]