def literal(self, o):
        """If o is a single object, returns an SQL literal as a string.
        If o is a non-string sequence, the items of the sequence are
        converted and returned as a sequence.

        Non-standard. For internal use; do not use this in your
        applications.
        """
        if isinstance(o, unicode):
            s = self.string_literal(o.encode(self.encoding))
        elif isinstance(o, bytearray):
            s = self._bytes_literal(o)
        elif isinstance(o, bytes):
            if PY2:
                s = self.string_literal(o)
            else:
                s = self._bytes_literal(o)
        elif isinstance(o, (tuple, list)):
            s = self._tuple_literal(o)
        else:
            s = self.escape(o, self.encoders)
            if isinstance(s, unicode):
                s = s.encode(self.encoding)
        assert isinstance(s, bytes)
        return s
If o is a single object, returns an SQL literal as a string.
        If o is a non-string sequence, the items of the sequence are
        converted and returned as a sequence.

        Non-standard. For internal use; do not use this in your
        applications.