Logging exceptions is as simple as adding the exc_info=True keyword argument to any log message, see entry for Logger.debug in http://docs.python.org/2/library/logging.html.
Example:
try:
raise Exception('lala')
except Exception:
logging.info('blah', exc_info=True)
output (depending, of course, on your log handler config):
2012-11-29 10:18:12,778 - root - INFO - : 3 - blah
Traceback (most recent call last):
File "", line 1, in
try: raise Exception('lala')
Exception: lala
