title: Flower Framework is not showing federated loss
body: <ol>
  <li>I am trying to use federated learning framework flower with TensorFlow. My code seems to compile fine but It's not showing federated loss and accuracy. What am I doing wrong?</li>
  </ol>
  <p>ServerSide Code :</p>
  <pre><code>import flwr as fl
  import sys
  import numpy as np
  
  class SaveModelStrategy(fl.server.strategy.FedAvg):
      def aggregate_fit(
          self,
          rnd,
          results,
          failures
      ):
          aggregated_weights = super().aggregate_fit(rnd, results, failures)
          &quot;&quot;&quot;if aggregated_weights is not None:
              # Save aggregated_weights
              print(f&quot;Saving round {rnd} aggregated_weights...&quot;)
              np.savez(f&quot;round-{rnd}-weights.npz&quot;, *aggregated_weights)&quot;&quot;&quot;
          return aggregated_weights
  
  # Create strategy and run server
  strategy = SaveModelStrategy()
  
  # Start Flower server for three rounds of federated learning
  fl.server.start_server(
          server_address = 'localhost:'+str(sys.argv[1]),
          #server_address = &quot;[::]:8080&quot; ,
          config={&quot;num_rounds&quot;: 2} ,
          grpc_max_message_length = 1024*1024*1024,
          strategy = strategy
  )
  </code></pre>
  <p>Server Side:
  <a href="https://i.stack.imgur.com/6IqNN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6IqNN.png" alt="enter image description here" /></a></p>