This is one of the shortest articles ever, almost nothing to explain here.

First, install Selenium2 through easy_install

sudo easy_install selenium

Then, simply go to the /Applications directory and create a symbolic link, because selenium looks for the Firefox binary in a  specific path:

$ cd /Applications
$ sudo ln -s FirefoxNightly.app Firefox.app

 

Time to test:

$ python
>>> from selenium import webdriver
>>> ff = webdriver.Firefox()

 

You should now see a new Firefox instance.

That’s it.