from logging import Formatter, FileHandler, StreamHandler, getLogger def addHandler(*, handler=None, stream=None, filename=None, filemode='a', format=None, datefmt=None, style='{', level=None, max_level=None, filters=(), logger=None): """stream, filename, filemode, format, datefmt: as per logging.basicConfig handler: use a precreated handler instead of creating a new one logger: logger to add the handler to (uses root logger if none specified) filters: an iterable of filters to add to the handler level: only messages of this level and above will be processed max_level: only messages of this level and below will be processed style: as per logging.basicConfig, but defaults to '{' (i.e. str.format) """ # Create the handler if one hasn't been passed in if handler is None: if filename is not None: handler = FileHandler(filename, filemode) else: handler = StreamHandler(stream) # Set up the formatting of the log messages # New API, so it can default to str.format instead of %-formatting formatter = Formatter(format, datefmt, style) handler.setFormatter(formatter) # Set up filtering of which messages to handle if level is not None: handler.setLevel(level) if max_level is not None: def level_ok(record): return record.levelno <= max_level handler.addFilter(level_ok) for filter in filters: handler.addFilter(filter) # Add the fully configured handler to the specified logger if logger is None: logger = getLogger() logger.addHandler(handler) return handler # Example of setting up the logging module to direct raw output to # sys.stdout and sys.stderr as appropriate import sys, logging # Let root logger handlers see all messages logging.getLogger().setLevel(logging.NOTSET) # Send WARNING and above to stderr addHandler(stream=sys.stderr, level=logging.WARNING) # Send INFO to stdout addHandler(stream=sys.stdout, level=logging.INFO, max_level=logging.INFO)"Hello world!") # only displayed once logging.warn("Hello world!") # only displayed once