Just install python 2.7 on your Computer. You don't need to run the above code on the N900.

This is the beauty of Python and platform independent code.

Just install ActivePython on your Windows PC and use the build in Module manager of ActivePython to install mechanize or any other required module. If you are using Linux you probably already have Python installed and the required modules are available through the package manager of you Distribution of choice.

Cheers,
Bjoern