ZMQ example using python3 and asyncio

Author: Bob McElrath

contrib/zmq/zmq_sub3.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+# Copyright (c) 2014-2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+import array
+import binascii
+import asyncio, zmq, zmq.asyncio
+import struct
+
+port = 28332
+
+zmqContext = zmq.asyncio.Context()
+
+async def recv_and_process():
+    zmqSubSocket = zmqContext.socket(zmq.SUB)
+    zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "hashblock")
+    zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "hashtx")
+    zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "rawblock")
+    zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "rawtx")
+    zmqSubSocket.connect("tcp://127.0.0.1:%i" % port)
+
+    poller = zmq.asyncio.Poller()
+    poller.register(zmqSubSocket, zmq.POLLIN)
+    while True:
+        s = await poller.poll()
+        msg = await s[0][0].recv_multipart()
+        topic = msg[0]
+        body = msg[1]
+        sequence = "Unknown";
+        if len(msg[-1]) == 4:
+          msgSequence = struct.unpack('<I', msg[-1])[-1]
+          sequence = str(msgSequence)
+        if topic == b"hashblock":
+            print('- HASH BLOCK ('+sequence+') -')
+            print(binascii.hexlify(body))
+        elif topic == b"hashtx":
+            print('- HASH TX  ('+sequence+') -')
+            print(binascii.hexlify(body))
+        elif topic == b"rawblock":
+            print('- RAW BLOCK HEADER ('+sequence+') -')
+            print(binascii.hexlify(body[:80]))
+        elif topic == b"rawtx":
+            print('- RAW TX ('+sequence+') -')
+            print(binascii.hexlify(body))
+
+try:
+    loop = zmq.asyncio.ZMQEventLoop()
+    asyncio.set_event_loop(loop)
+    loop.run_until_complete(setup())
+except KeyboardInterrupt:
+    zmqContext.destroy()