def tx_for_tx_hash(self, tx_hash):
        "Get a Tx by its hash."
        url = self.base_url("get_tx", b2h_rev(tx_hash))
        r = json.loads(urlopen(url).read().decode("utf8"))
        tx = Tx.parse(io.BytesIO(h2b(r.get("data").get("tx_hex"))))
        return tx
Get a Tx by its hash.