some useful helpers from tornado's escape.py: def utf8(value): if isinstance(value, unicode): return value.encode("utf-8") asse

some useful helpers from tornado's escape.py: def utf8(value): if isinstance(value, unicode): return value.encode("utf-8") assert isinstance(value, str) return value def _unicode(value): if isinstance(value, str): return value.decode("utf-8") assert isinstance(value, unicode) return value