Can anyone correct the code

import collections
import tensorflow as tf
import tensorflow_federated as tff

Load simulation data.

source, _ = tff.simulation.datasets.emnist.load_data()
def client_data(n):
return source.create_tf_dataset_for_client(source.client_ids[n]).map(
lambda e: (tf.reshape(e[‘pixels’], [-1]), e[‘label’])
).repeat(10).batch(20)

Pick a subset of client devices to participate in training.

train_data = [client_data(n) for n in range(3)]

Wrap a Keras model for use with TFF.

keras_model = tf.keras.models.Sequential([
tf.keras.layers.Dense(
10, tf.nn.softmax, input_shape=(784,), kernel_initializer=‘zeros’)
])
tff_model = tff.learning.models.functional_model_from_keras(
keras_model,
loss_fn=tf.keras.losses.SparseCategoricalCrossentropy(),
input_spec=train_data[0].element_spec,
metrics_constructor=collections.OrderedDict(
accuracy=tf.keras.metrics.SparseCategoricalAccuracy))

Simulate a few rounds of training with the selected client devices.

trainer = tff.learning.algorithms.build_weighted_fed_avg(
tff_model,
client_optimizer_fn=tff.learning.optimizers.build_sgdm(learning_rate=0.1))
state = trainer.initialize()
for _ in range(5):
result = trainer.next(state, train_data)
state = result.state
metrics = result.metrics
print(metrics[‘client_work’][‘train’][‘accuracy’])