Keep track of whitespaces and column 80 overflow

When working in Emacs python mode I keep track of whitespaces and column 80 overflow using a whitespace-mode that is part of Emacs 22+

Here is a snippet from my .emacs:

;; nuke trailing whitespaces when writing to a file
(add-hook 'write-file-hooks 'delete-trailing-whitespace)

;; display only tails of lines longer than 80 columns, tabs and
;; trailing whitespaces
(setq whitespace-line-column 80
      whitespace-style '(tabs trailing lines-tail))

;; face for long lines' tails
(set-face-attribute 'whitespace-line nil
                    :background "red1"
                    :foreground "yellow"
                    :weight 'bold)

;; face for Tabs
(set-face-attribute 'whitespace-tab nil
                    :background "red1"
                    :foreground "yellow"
                    :weight 'bold)

;; activate minor whitespace mode when in python mode
(add-hook 'python-mode-hook 'whitespace-mode)

Because my Emacs is setup to save/restore desktop I’ve added the following lines to play nicely with the whitespace-mode when restoring a previous session:

;; save whitespace-mode variables
(add-to-list 'desktop-globals-to-save 'whitespace-line-column)
(add-to-list 'desktop-globals-to-save 'whitespace-style)

This is how trailing whitespaces, tabs and long lines tails look in my Emacs buffer:

import sys

def main():
    """This line is longer than 80 cloumns ............................."""
    values = [
        # next line contains leading tab
        'qwerty',
        'test',    
        ]

   
if __name__ == '__main__':
    main() # this line contains trailing whitespaces    

UPDATE November 15th, 2011
In Emacs 24 you have to add a face specifier to the whitespace-style to make trailing whitespaces highlighted:

(setq whitespace-line-column 80
      whitespace-style '(face tabs trailing lines-tail))