Is this the right way to write a codec error handler?

[Steven D'Aprano]

I want an error handler that falls back on Latin-1 for anything which 
cannot be decoded. Is this the right way to write it?


def latin1_fallback(exception):
    assert isinstance(exception, UnicodeError)
    start, end = exception.start, exception.end
    obj = exception.object
    if isinstance(exception, UnicodeDecodeError):
        return (obj[start:end].decode('latin1'), end+1)
    elif isinstance(exception, UnicodeEncodeError):
        return (obj[start:end].encode('latin1'), end+1)
    else:
        raise



Comments, corrections and criticisms welcome.

Thanks.


-- 
Steve