@asyncio.coroutine<EOL><INDENT>def personal_sign(self, message, account, password=None):<DEDENT>
return (yield from self.rpc_call('<STR_LIT>',<EOL>[message, account, password]))<EOL>
https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal_sign

        :param message: Message for sign
        :type message: str

        :param account: Account address
        :type account: str

        :param password: Password of account (optional)
        :type password: str

        :return: signature
        :rtype: str