performance - Does python logging flush every log? -

when write log file using standard module logging, each log flushed disk separately? example, following code flush log 10 times?

logging.basicconfig(level=logging.debug, filename='debug.log')     in xrange(10):         logging.debug("test") 

if so, slow down ?

yes, flush output @ every call. can see in source code streamhandler:

def flush(self):     """     flushes stream.     """     self.acquire()     try:         if self.stream , hasattr(self.stream, "flush"):             self.stream.flush()     finally:         self.release()  def emit(self, record):     """     emit record.      if formatter specified, used format record.     record written stream trailing newline.  if     exception information present, formatted using     traceback.print_exception , appended stream.  if stream     has 'encoding' attribute, used determine how     output stream.     """     try:         msg = self.format(record)         stream = self.stream         stream.write(msg)         stream.write(self.terminator)         self.flush()   # <---     except (keyboardinterrupt, systemexit): #pragma: no cover         raise     except:         self.handleerror(record) 

i wouldn't mind performance of logging, @ least not before profiling , discovering bottleneck. anyway can create handler subclass doesn't perform flush @ every call emit(even though risk lose lot of logs if bad exception occurs/the interpreter crashes).