Refactored .format() to f-strings for floats.

examples/fattree_tcp.py

@@ -14,7 +14,7 @@
 
 env = simpy.Environment()
 
-n_flows = 64
+n_flows = 512 
 finish_time = 10
 k = 32
 pir = 10000000000  # 10Gbps

examples/real_traffic/tcp_echo_client.py

@@ -17,8 +17,7 @@
 
     try:
         message = 'This is a new message.  It will be echoed.'
-        print('Sent "{}" at time {:.2f}.'.format(message,
-                                                 time.time() - init_time))
+        print(f'Sent "{message}" at time {(time.time() - init_time):.2f}')
         sock.sendall(bytes(message, 'utf-8'))
 
         amount_received = 0
@@ -27,9 +26,7 @@
         while amount_received < amount_expected:
             data = sock.recv(64)
             amount_received += len(data)
-            print('Received "{}" at time {:.2f}.'.format(
-                data,
-                time.time() - init_time))
+            print(f'Received "{data}" at time {(time.time() - init_time):.2f}.')
 
     finally:
         print('Disconnecting.')

examples/real_traffic/tcp_echo_server.py

@@ -34,18 +34,15 @@
             # Receive the data in small chunks and retransmit it
             while True:
                 data = connection.recv(64)
-                print('received "{}" at time {:.2f}.'.format(
-                    data,
-                    time.time() - init_time))
+                print(f'received "{data}" at time {(time.time() - init_time):.2f}.')
                 if data:
                     print('sending "{}" back to the client at time {:.2f}'.
                           format(data,
                                  time.time() - init_time))
                     connection.sendall(data)
                 else:
-                    print('no more data from {} at time {:.2f}'.format(
-                        client_address,
-                        time.time() - init_time))
+                    print(f"no more data from {client_address} at time "
+                    f"{(time.time() - init_time):.2f}")
                     break
 
         finally:

examples/real_traffic/udp_echo_client.py

@@ -21,5 +21,5 @@
                 (args.server_host, int(args.server_port)))
     received = str(sock.recv(1024), "utf-8")
 
-    print("Sent:     {}".format(message))
-    print("Received: {}".format(received))
+    print(f"Sent:     {message}")
+    print(f"Received: {received}")

examples/real_traffic/udp_echo_server.py

@@ -13,7 +13,7 @@ class MyUDPHandler(socketserver.BaseRequestHandler):
     def handle(self):
         data = self.request[0].strip()
         socket = self.request[1]
-        print("{} wrote: ".format(self.client_address))
+        print(f"{self.client_address} wrote: ")
         print(data)
         socket.sendto(data, self.client_address)
 

ns/packet/bbr_generator.py

@@ -141,14 +141,9 @@ def run(self):
                 self.packet_in_flight += packet.size
                 if self.debug:
                     print(
-                        "Send packet {:d} with size {:d}, "
-                        "flow_id {:d} at time {:.4f}, delivered_time {:.4f}.".format(
-                            packet.packet_id,
-                            packet.size,
-                            packet.flow_id,
-                            self.env.now,
-                            packet.delivered_time,
-                        )
+                        f"Send packet {packet.packet_id} with size {packet.size}, "
+                        f"flow_id {packet.flow_id} at time {self.env.now:.4f}, "
+                        f"and the packet delivered time is {packet.delivered_time:.4f}."
                     )
                 assert packet.delivered_time > 0
                 self.out.put(packet)
@@ -165,8 +160,8 @@ def run(self):
 
                 if self.debug:
                     print(
-                        "Setting a timer for packet {:d} with an RTO"
-                        " of {:.4f}.".format(packet.packet_id, self.rto)
+                        f"Setting a timer for packet {packet.packet_id} with an RTO"
+                        f" of {self.rto:.4f}."
                     )
 
     def timeout_callback(self, packet_id=0):
@@ -175,8 +170,8 @@ def timeout_callback(self, packet_id=0):
         packet_id = self.max_ack
         if self.debug:
             print(
-                "Timer expired for packet {:d} {:d} at time {:.4f}.".format(
-                    packet_id, self.flow.fid, self.env.now
+                f"Timer expired for packet {packet_id} {self.flow.fid} "
+                f"at time {self.env.now:.4f}."
                 )
             )
 
@@ -203,12 +198,8 @@ def timeout_callback(self, packet_id=0):
             self.rto = 60
         if self.debug:
             print(
-                "to Resending packet {:d} with flow_id {:d} at time {:.4f} with a timeout time {:4f}.".format(
-                    resent_pkt.packet_id,
-                    resent_pkt.flow_id,
-                    self.env.now,
-                    self.env.now + self.rto,
-                )
+                f"to Resending packet {resent_pkt.packet_id} with flow_id {resent_pkt.flow_id} "
+                f"at time {self.env.now:.4f} with a timeout time {self.env.now + self.rto:4f}."
             )
 
         # starting a new timer for this segment and doubling the retransmission timeout
@@ -295,9 +286,8 @@ def put(self, ack):
 
             if self.debug:
                 print(
-                    "dup Resending packet {:d} with flow_id {:d} at time {:.4f}.".format(
-                        resent_pkt.packet_id, resent_pkt.flow_id, self.env.now
-                    )
+                    f"dup Resending packet {resent_pkt.packet_id} with flow_id "
+                    f"{resent_pkt.flow_id} at time {self.env.now:.4f}."
                 )
             self.out.put(resent_pkt)
 
@@ -358,14 +348,12 @@ def put(self, ack):
 
             if self.debug:
                 print(
-                    "Ack received till sequence number {:d} at time {:.4f}.".format(
-                        ack.ack, self.env.now
-                    )
+                    f"Ack received till sequence number {ack.ack} at time "
+                    f"{self.env.now:.4f}."
                 )
                 print(
-                    "Congestion window size = {:.1f}, last ack = {:d}.".format(
-                        self.congestion_control.cwnd, self.last_ack
-                    )
+                    f"Congestion window size = {self.congestion_control.cwnd:.1f}, "
+                    f"last ack = {self.last_ack}."
                 )
 
             if bbr_update:

ns/packet/dist_generator.py

@@ -88,14 +88,9 @@ def run(self):
 
             if self.debug:
                 print(
-                    "DistPacketGenerator {} sent packet {:d} with size {:d}, "
-                    "flow_id {:d} at time {:.4f}.".format(
-                        self.element_id,
-                        packet.packet_id,
-                        packet.size,
-                        packet.flow_id,
-                        self.env.now,
-                    )
+                    f"DistPacketGenerator {self.element_id} sent packet {packet.packet_id}"
+                    f" with size {packet.size}, "
+                    f"flow_id {packet.flow_id} at time {self.env.now:.4f}."
                 )
 
             # waits for the next transmission

ns/packet/proxy_sink.py

@@ -238,17 +238,18 @@ def put(self, packet):
                 self.last_arrival[rec_index] = now
 
             if self.debug:
-                print("At time {:.2f}, packet {:d} arrived at {}.".format(
-                    now, packet.packet_id, self.element_id))
+                print(f"At time {now:.2f}, packet {packet.packet_id} "
+                f"arrived at {self.element_id}.")
                 if self.rec_waits and len(self.packet_sizes[rec_index]) >= 10:
                     bytes_received = sum(self.packet_sizes[rec_index][-9:])
                     time_elapsed = self.env.now - (
                         self.packet_times[rec_index][-10] +
                         self.waits[rec_index][-10])
                     if time_elapsed > 0:
                         print(
-                            "Average throughput (last 10 packets): {:.2f} bytes/second."
-                            .format(bytes_received / time_elapsed))
+                            f"Average throughput (last 10 packets): "
+                            f"{(bytes_received / time_elapsed):.2f} bytes/second."
+                        )
 
             self.packets_received[rec_index] += 1
             self.bytes_received[rec_index] += packet.size

ns/packet/sink.py

@@ -91,19 +91,17 @@ def put(self, packet):
 
         if self.debug:
             print(
-                "At time {:.2f}, packet {:d} in flow {:d} arrived.".format(
-                    now, packet.packet_id, packet.flow_id
-                )
+                f"At time {now:.2f}, packet {packet.packet_id} in "
+                f"flow {packet.flow_id} arrived."
             )
             if self.rec_waits and len(self.packet_sizes[rec_index]) >= 10:
                 bytes_received = sum(self.packet_sizes[rec_index][-9:])
                 time_elapsed = self.env.now - (
                     self.packet_times[rec_index][-10] + self.waits[rec_index][-10]
                 )
                 print(
-                    "Average throughput (last 10 packets): {:.2f} bytes/second.".format(
-                        float(bytes_received) / time_elapsed
-                    )
+                    f"Average throughput (last 10 packets): "
+                    f"{(float(bytes_received) / time_elapsed):.2f} bytes/second."
                 )
 
         self.packets_received[rec_index] += 1

ns/port/wire.py

@@ -62,13 +62,12 @@ def run(self):
                 self.out.put(packet)
 
                 if self.debug:
-                    print("Left wire #{} at {:.3f}: {}".format(
-                        self.wire_id, self.env.now, packet))
+                    print(f"Left wire #{self.wire_id} at "
+                        f"{self.env.now:.3f}: {packet}")
             else:
                 if self.debug:
-                    print("Dropped on wire #{} at {:.3f}: {}".format(
-                        self.wire_id, self.env.now, packet))
-
+                    print(f"Dropped on wire #{self.wire_id} at "
+                    f"{self.env.now:.3f}: {packet}")
     def put(self, packet):
         """ Sends a packet to this element. """
         self.packets_rec += 1