def dict_comp_handle(self, loc, tokens):
        """Process Python 2.7 dictionary comprehension."""
        internal_assert(len(tokens) == 3, "invalid dictionary comprehension tokens", tokens)
        if self.target.startswith("3"):
            key, val, comp = tokens
            return "{" + key + ": " + val + " " + comp + "}"
        else:
            key, val, comp = tokens
            return "dict(((" + key + "), (" + val + ")) " + comp + ")"
Process Python 2.7 dictionary comprehension.