Light weight IDE like pywin for os x 10.6

[python]

I have looked a while for this answer.  Sorry if it right before me.

I have move from Windows to os x.  The thing I miss most is pywin.
I know you can purchase or download full IDE's for python or even use
Eclipse.   I really liked the ability to switch from interactive
interpreter to editor easily.  The autocompletion is very helpful so
idle does not quite cut it for me.