Fix lbbroker[23].py for python2 and python3

Python examples lbbroker2.py and lbbroker3.py failed to run
on both python2 and python3.

So i made minimal changes to make it possible.

I also fixed few PEP8 problems my editor complained about, mainly
long lines and spaces on wrong places.

examples/Python/lbbroker2.py

@@ -7,13 +7,15 @@
 
 """
 
+from __future__ import print_function
 import threading
 import time
 import zmq
 
 NBR_CLIENTS = 10
 NBR_WORKERS = 3
 
+
 def worker_thread(worker_url, context, i):
     """ Worker using REQ socket to do LRU routing """
 
@@ -24,16 +26,17 @@ def worker_thread(worker_url, context, i):
 
     socket.connect(worker_url)
 
-    # Tell the borker we are ready for work
+    # Tell the broker we are ready for work
     socket.send(b"READY")
 
     try:
         while True:
-            
+
             address, empty, request = socket.recv_multipart()
 
-            print("%s: %s\n" % (socket.identity.decode('ascii'), request.decode('ascii')), end='')
-
+            print("%s: %s\n" % (socket.identity.decode('ascii'),
+                                request.decode('ascii')), end='')
+
             socket.send_multipart([address, b'', b'OK'])
 
     except zmq.ContextTerminated:
@@ -45,7 +48,7 @@ def client_thread(client_url, context, i):
     """ Basic request-reply client using REQ socket """
 
     socket = context.socket(zmq.REQ)
-    
+
     # Set client identity. Makes tracing easier
     socket.identity = (u"Client-%d" % (i)).encode('ascii')
 
@@ -55,7 +58,8 @@ def client_thread(client_url, context, i):
     socket.send(b"HELLO")
     reply = socket.recv()
 
-    print("%s: %s\n" % (socket.identity.decode('ascii'), reply.decode('ascii')), end='')
+    print("%s: %s\n" % (socket.identity.decode('ascii'),
+                        reply.decode('ascii')), end='')
 
 
 def main():
@@ -72,15 +76,15 @@ def main():
     backend = context.socket(zmq.ROUTER)
     backend.bind(url_worker)
 
-
-
     # create workers and clients threads
     for i in range(NBR_WORKERS):
-        thread = threading.Thread(target=worker_thread, args=(url_worker, context, i, ))
+        thread = threading.Thread(target=worker_thread,
+                                  args=(url_worker, context, i, ))
         thread.start()
 
     for i in range(NBR_CLIENTS):
-        thread_c = threading.Thread(target=client_thread, args=(url_client, context, i, ))
+        thread_c = threading.Thread(target=client_thread,
+                                    args=(url_client, context, i, ))
         thread_c.start()
 
     # Logic of LRU loop
@@ -91,7 +95,7 @@ def main():
 
     # Queue of available workers
     available_workers = 0
-    workers_list      = []
+    workers_list = []
 
     # init poller
     poller = zmq.Poller()
@@ -111,7 +115,6 @@ def main():
 
             # Queue worker address for LRU routing
             message = backend.recv_multipart()
-
             assert available_workers < NBR_WORKERS
 
             worker_addr = message[0]
@@ -121,22 +124,22 @@ def main():
             workers_list.append(worker_addr)
 
             #   Second frame is empty
-            empty        = message[1]
-            assert empty == ""
+            empty = message[1]
+            assert empty == b""
 
             # Third frame is READY or else a client reply address
             client_addr = message[2]
 
             # If client reply, send rest back to frontend
-            if client_addr != "READY":
+            if client_addr != b'READY':
 
                 # Following frame is empty
                 empty = message[3]
-                assert empty == ""
+                assert empty == b""
 
                 reply = message[4]
 
-                frontend.send_multipart([client_addr, "", reply])
+                frontend.send_multipart([client_addr, b"", reply])
 
                 client_nbr -= 1
 
@@ -150,19 +153,19 @@ def main():
                 # Now get next client request, route to LRU worker
                 # Client request is [address][empty][request]
 
-                [client_addr, empty, request ] = frontend.recv_multipart()
+                [client_addr, empty, request] = frontend.recv_multipart()
 
-                assert empty == ""
+                assert empty == b""
 
                 #  Dequeue and drop the next worker address
-                available_workers -= 1
+                available_workers += -1
                 worker_id = workers_list.pop()
 
-                backend.send_multipart([worker_id, "", client_addr, "", request])
-
+                backend.send_multipart([worker_id, b"",
+                                        client_addr, b"", request])
 
     #out of infinite loop: do some housekeeping
-    time.sleep (1)
+    time.sleep(1)
 
     frontend.close()
     backend.close()

examples/Python/lbbroker3.py

@@ -8,10 +8,12 @@
    context and conceptually acts as a separate process.
 
    Author: Min RK <benjaminrk(at)gmail(dot)com>
-   Adapted from lruqueue.py by Guillaume Aubert (gaubert) <guillaume(dot)aubert(at)gmail(dot)com>
+   Adapted from lruqueue.py by
+           Guillaume Aubert (gaubert) <guillaume(dot)aubert(at)gmail(dot)com>
 
 """
 
+from __future__ import print_function
 import threading
 import time
 import zmq
@@ -22,6 +24,7 @@
 NBR_CLIENTS = 10
 NBR_WORKERS = 3
 
+
 def worker_thread(worker_url, i):
     """ Worker using REQ socket to do LRU routing """
     context = zmq.Context.instance()
@@ -33,16 +36,17 @@ def worker_thread(worker_url, i):
 
     socket.connect(worker_url)
 
-    # Tell the borker we are ready for work
+    # Tell the broker we are ready for work
     socket.send(b"READY")
 
     try:
         while True:
-            
+
             address, empty, request = socket.recv_multipart()
 
-            print("%s: %s\n" % (socket.identity.decode('ascii'), request.decode('ascii')), end='')
-
+            print("%s: %s\n" % (socket.identity.decode('ascii'),
+                                request.decode('ascii')), end='')
+
             socket.send_multipart([address, b'', b'OK'])
 
     except zmq.ContextTerminated:
@@ -55,7 +59,7 @@ def client_thread(client_url, i):
     context = zmq.Context.instance()
 
     socket = context.socket(zmq.REQ)
-    
+
     # Set client identity. Makes tracing easier
     socket.identity = (u"Client-%d" % (i)).encode('ascii')
 
@@ -65,7 +69,8 @@ def client_thread(client_url, i):
     socket.send(b"HELLO")
     reply = socket.recv()
 
-    print("%s: %s\n" % (socket.identity.decode('ascii'), reply.decode('ascii')), end='')
+    print("%s: %s\n" % (socket.identity.decode('ascii'),
+                        reply.decode('ascii')), end='')
 
 
 class LRUQueue(object):
@@ -109,7 +114,7 @@ def handle_backend(self, msg):
 
             if self.client_nbr == 0:
                 # Exit after N messages
-                self.loop.add_timeout(time.time()+1, self.loop.stop)
+                self.loop.add_timeout(time.time() + 1, self.loop.stop)
 
         if self.available_workers == 1:
             # on first recv, start accepting frontend messages
@@ -131,6 +136,7 @@ def handle_frontend(self, msg):
             # stop receiving until workers become available again
             self.frontend.stop_on_recv()
 
+
 def main():
     """main method"""
 
@@ -151,7 +157,8 @@ def main():
         thread.start()
 
     for i in range(NBR_CLIENTS):
-        thread_c = threading.Thread(target=client_thread, args=(url_client, i, ))
+        thread_c = threading.Thread(target=client_thread,
+                                    args=(url_client, i, ))
         thread_c.daemon = True
         thread_c.start()