Elpy is an Emacs package to bring powerful Python editing to Emacs. It combines a number of other packages, both written in Emacs Lisp as well as Python.

You can find the documentation on the wiki.

You can also read the detailed installation instructions.

First, install the required Python packages:

pip install elpy rope pyflakes pep8

(Note: If you are installing the development version of elpy, do not install the elpy Python package, but simply put the repository in your PYTHONPATH.)

Evaluate this in your *scratch* buffer:

(add-to-list 'package-archives
             '("marmalade" . "http://marmalade-repo.org/packages/"))

Then run M-x package-install RET elpy RET.

Finally, add the following to your .emacs:

(package-initialize)
(elpy-enable)

Done.