Filter Bokeh Logger Messages in Python

Is it possible to stop or redirect bokeh logging info / warning / other messages? If they can be redirected to a file, how can this be done? If the logging level can be changed so that these messages are not shown, how could this be done using python? This is not for a bokeh server. I want to prevent messages like the following being printed to the screen:

INFO:bokeh.core.state:Session output file ‘./example.html’ already exists, will be overwritten.

WARNING:/anaconda/lib/python2.7/site-packages/bokeh/core/validation/check.pyc:W-1001 (NO_DATA_RENDERERS): Plot has no data renderers: Figure