Improve the generator so that it is possible to change the batch_size value on the fly via the send() method.

To change the batch_size value on the fly via the send() method in a generator, you can implement a generator that supports external value passing. Example:

def batch_generator(initial_batch_size):
    batch_size = initial_batch_size
    while True:
        new_batch_size = (yield batch_size)  # return current batch_size and wait for a new value
        if new_batch_size is not None:
            batch_size = new_batch_size

# Usage:
gen = batch_generator(5)
print(next(gen))        # Outputs 5
print(gen.send(10))     # Changes batch_size to 10 and outputs 10
print(gen.send(None))   # Keeps batch_size at 10 and outputs 10

Thus, through send() you can pass a new batch_size value, which will be used in the next generator cycle.