logutils.py

def streamdup(stream, filename, mode='a+'):
    """
    Aka "tee".
    Duplicate stream output to the file with given name.
    
    Usage:
    >>> streamcopy(sys.stderr, 'myfile', 'a+')
    """
    stream._tee = open(filename, mode)
    def write(*a): TextIOWrapper.write(stream, *a); stream._tee.write(*a)
    stream.write = write 


#import logging

#LOGFORMAT = '%(levelname)s %(asctime)s %(module)s.py: %(message)s'

#def add_log_handler(handler):
    #handler.setFormatter(logging.Formatter(LOGFORMAT))
    #logging.getLogger().addHandler(handler)


class TeeLogger(logging.LoggerAdapter):
    """
    This logger will log messages to the file and pass on to the other 
    logger which it is attached to.
    """
    def __init__(self, filename, logger=None):
        """
        param `logger`: the logger instance which this logger will be attached to.
        default is the root logger.
        """
        self.logger = logger or logging.getLogger()
        
        _filehandler = logging.FileHandler(filename)
        _filehandler.setFormatter(self.logger.handlers[0].formatter)
        
        self.filelogger = logging.Logger(id(filename), level=self.logger.level)
        self.filelogger.addHandler(_filehandler)
        
    def log(self, level, msg, *args, **kwargs):
        if self.isEnabledFor(level):
            self.logger.log(level, msg, *args, **kwargs)
            self.filelogger.log(level, msg, *args, **kwargs)