The libraries needed are: xlutils, xlrd and xlwt. They are all under the package called xlutils. So just issue the following command.
sudo pip install xlutils
localhost:~ birdchan$ python Python 2.7.2 (default, Jun 16 2012, 12:38:40) [GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import xlutils >>>
Should have no error messages.