Convert to a Ledger transaction (no trailing blank line)

def ledger(self):
        """Convert to a Ledger transaction (no trailing blank line)"""
        self.balance()  # make sure the transaction balances

        s = "{0}/{1:02}/{2:02}  {3}\n".format(
            self.date.year,
            self.date.month,
            self.date.day,
            self.desc.replace('\n', ' ')
        )
        for src in self.src:
            s += "  {0.account}  ${0.amount}\n".format(src)
        for dst in self.dst:
            s += "  {0.account}  ${0.amount}\n".format(dst)
        return s