ISBN Barecode reader in Python?

[Joseph]

All: I have written a program to query Amazon with ISBN and get the
book details. I would like to extend so that I can read ISBN from the
barcode (I will take a photo of the same using webcam or mobile). Are
there any opensource/free SDK doing the same? As it is a hobby
project, I don't like to spend money on the SDK.

Thank you all for your suggestions/time,
Joseph
http://www.jjude.com