How can a Python multiprocessing pool be used within a loop?

edit

Here is an example of how to use a Python multiprocessing pool within a loop:

import multiprocessing

def func(x):
    return x**2

if __name__ == '__main__':
    pool = multiprocessing.Pool(processes=3)
    for i in range(10):
        result = pool.apply_async(func, [i])
        print(result.get())
    pool.close()
    pool.join()

In this example, we define a function func() that takes a number x and returns its square. We then create a multiprocessing pool with three processes using the multiprocessing.Pool() function.

In the loop, we use the pool's apply_async() method to submit a new task to the pool for each iteration. The apply_async() method takes as arguments the function to be executed and the function arguments.

We then call the get() method on the result object returned by apply_async(). The get() method blocks until the result becomes available from the process.

Finally, we call pool.close() and pool.join() to clean up the pool and wait for all processes to complete.