logging.py 文件源码

def __init__(self, *args, **kwargs):
        client = kwargs.pop('client_cls', Client)
        if len(args) == 1:
            arg = args[0]
            args = args[1:]
            if isinstance(arg, Client):
                self.client = arg
            else:
                raise ValueError(
                    'The first argument to %s must be a Client instance, '
                    'got %r instead.' % (
                        self.__class__.__name__,
                        arg,
                    ))
        elif 'client' in kwargs:
            self.client = kwargs.pop('client')
        else:
            self.client = client(*args, **kwargs)

        logging.Handler.__init__(self, level=kwargs.get('level', logging.NOTSET))