logbook-test.py

#!/usr/bin/env python
# coding=utf8

import logbook

handler = logbook.NullHandler(bubble=False)
handler.push_application()
logbook.info('Hello, world')

logbook-test2.py

#!/usr/bin/env python
# coding=utf8

import logbook

handler = logbook.NullHandler(bubble=True)
handler.push_application()
logbook.info('Hello, world')

logbook-test3.py

#!/usr/bin/env python
# coding=utf8

import logbook

handler = logbook.NullHandler()
handler.push_application()
logbook.info('Hello, world')

logbook-test4.py

#!/usr/bin/env python
# coding=utf8

import logbook

logbook.info('Hello, world')

Test results

# compare: http://packages.python.org/Logbook/api/handlers.html

$ python logbook-test.py 
$ python logbook-test2.py 
$ python logbook-test3.py 
$ python logbook-test4.py 
[2012-03-14 12:45] INFO: Generic: Hello, world