A metadata plugin for isbnlib (https://pypi.python.org/pypi/isbnlib) using the service BnF Catalogue Général (for books in french).

To install, from the command line, enter (in some cases you have to precede the command with sudo):

$ pip install isbnlib-bnf

After install, a new metadata provider (bnf) is available in isbnlib.

For available plugins check here.