SciTE is based on the SCIntilla editor engine. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs. Plug-in suport for Python API (there is script which create description of all Python API on your computer), the best syntax highlighting, work on Linux, Solaris, Win family.
Here are SciTE features useful while editing Python files: syntax highlighting, code folding, auto-indent, brace matching, codepage/unicode support, multiple documents, context help, code execution, output pane, external tools support, RegExp find/replace, text export (HTML, RTF, PDF, LaTeX, XML).
SciTE currently supports about 50 computer languages.
Get it from http://www.scintilla.org/SciTE.html
I'm also using it, not only for Python 
It highlights JSP pages verry good too (best IMHO). Does anybody know a way to use SciTE for Python debugging?
I use it too, and Yasc is useful to configure it. it can be downloaded at www.fw-web.de/download/yasc.rar and with source at www.fw-web.de/download/yasc+src.rar.
yasc is now called tsct, download it at tsct.sf.net
This is not exactly a debugger, but is still useful. Read the comment at the bottom : http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52215