Python
rope & ropemacs
rope is a library for refactoring and manipulating Python code. ropemacs is an Emacs interface to the rope library.
Pymacs
Pymacs is an Emacs extension that enables the use of Python alongside with Emacs Lisp.
emacs-for-python
emacs-for-python is a bundle of the above modes (and more), and it's an easy way to turn Emacs into a Python IDE.