For the last few years I have been specializing at web scraping and collected what I found useful into this library.
All code is pure Python and has been run across multiple Linux servers, Windows machines, as well as Google App Engine.
Some options to install the webscraping package:
Checkout the repository: hg clone https://code.google.com/p/webscraping/
Download the zip: https://pypi.python.org/pypi/webscraping/
Install with pypi: pip install webscraping
The only dependency is python 2.5 or higher.