change minimal python version in tests to 3.7 (#39)

tests/benchmark_throughput.py

@@ -96,21 +96,31 @@ def benchmark_throughput(num_experts=16, num_handlers=None, num_clients=128, num
     total_examples = batch_size * num_clients * num_batches_per_client
 
     print('\n' * 3)
-    print("Benchmark finished, status:", ["Success", "Failure"][benchmarking_failed.is_set()])
-    print(f"Server parameters: {num_experts=} {num_handlers=} {max_batch_size=} {expert_cls=} {hid_dim=} {device=}")
-    print(f"Client parameters: {num_clients=} {num_batches_per_client=} {batch_size=} {backprop=}")
-    print(f"Results: ")
-    print(f"\tServer startup took {time_between('began_launching_server', 'server_ready') :.3f} s. "
-          f"({time_between('began_launching_server', 'created_experts') :.3f} s. experts + "
-          f"{time_between('created_experts', 'server_ready') :.3f} s. networking)")
-    print(f"\tProcessed {total_examples} examples in {time_between('server_ready', 'clients_finished') :.3f}")
-    print(f"\tThroughput for {'forward + backward' if backprop else 'forward'} passes: "
-          f"{total_examples / time_between('server_ready', 'clients_finished') :.3f} samples / s.")
-    print(f"\tBenchmarking took {time_between('started', 'server_shutdown_finished') :.3f} s.")
+    print("Benchmark finished, status:".format(["Success", "Failure"][benchmarking_failed.is_set()]))
+    print("Server parameters: num_experts={}, num_handlers={}, max_batch_size={}, expert_cls={}, hid_dim={}, device={}"
+        .format(num_experts, num_handlers, max_batch_size, expert_cls, hid_dim, device))
+    print("Client parameters: num_clients={}, num_batches_per_client={}, batch_size={}, backprop={}"
+        .format(num_clients, num_batches_per_client, batch_size, backprop))
+
+    startup_time = time_between('began_launching_server', 'server_ready')
+    experts_time = time_between('began_launching_server', 'created_experts')
+    networking_time = time_between('created_experts', 'server_ready')
+    process_examples_time = time_between('server_ready', 'clients_finished')
+    overall_time = time_between('started', 'server_shutdown_finished')
+
+    stage = 'forward + backward' if backprop else 'forward'
+
+    print("Results: ")
+    print("\tServer startup took {} s. ({} s. experts + {} s. networking)".format(startup_time, experts_time, networking_time, '.3f'))
+    print("\tProcessed {} examples in {}".format(total_examples, time_betweenprocess_examples_time, '.3f'))
+    print("\tThroughput for {} passes: {} samples / s.".format(stage, total_examples / process_examples_time, '.3f'))
+    print("\tBenchmarking took {} s.".format(overall_time, '.3f'))
+
     if benchmarking_failed.is_set():
         print("Note: benchmark code failed, timing/memory results only indicate time till failure!")
     print_device_info(device)
     print(flush=True)
+
     assert not benchmarking_failed.is_set()