'Logs an exception.  This is called by :meth:`handle_exception`
if debugging is disabled and right before the handler is called.
The default implementation logs the exception as error on the
:attr:`logger`.
.. versionadded:: 0.8'

def log_exception(self, exc_info):

    self.logger.error(('Exception    on    %s    [%s]' % (request.path, request.method)), exc_info=exc_info)
