Example taken from the logbook docs, not working as of 0.9.0.

simplelogbook.py

# from https://pythonhosted.org/Logbook/api/handlers.html#logbook.Handler
#
# > By default messages sent to that handler will not go to a handler on an
# > outer level on the stack, if handled. This can be changed by setting
# > bubbling to True. This setup for example would not have any effect:
# >
# >   handler = NullHandler(bubble=True)
# >   handler.push_application()
# >
# > Whereas this setup disables all logging for the application:
# >
# > handler = NullHandler()
# > handler.push_application()
#
# The small script below tries to recreate the example minimally as accurate
# as possible:

from logbook import NullHandler, critical

handler = NullHandler(bubble=True)
handler.push_application()

critical('sample message, should bubble')