code: def tx_for_tx_hash(self, tx_hash):
          
          try:
              url_append = "?token=%s&includeHex=true" % self.api_key
              url = self.base_url("txs/%s%s" % (b2h_rev(tx_hash), url_append))
              result = json.loads(urlopen(url).read().decode("utf8"))
              tx = Tx.parse(io.BytesIO(h2b(result.get("hex"))))
              return tx
          except Exception:
              raise Exception
docs: returns the pycoin.tx object for tx_hash