Here is a simple example of pipes. We have one process pipe that outputs numbers from 0 to 9, and a second process pipe that takes the numbers and squares them:

1. Let's import the multiprocessing library:

import multiprocessing

2. The pipe function returns a pair of connection objects connected by a two-way pipe. In the example, out_pipe contains the numbers from 0 to 9, which were generated by the target function of create_items:

def create_items(pipe):
    output_pipe, _ = pipe
    for item in range(10):
        output_pipe.send(item)
    output_pipe.close()

3. The multiply_items function is based on two pipes, pipe_1 and pipe_2:

 def multiply_items(pipe_1, pipe_2):
    close, input_pipe = pipe_1
    close.close()
    output_pipe, _ = pipe_2
    try:
        while True:
            item = input_pipe.recv()

4. This function returns the product of the elements of each pipe:

           output_pipe.send(item * item)
 except EOFError:
        output_pipe.close()

5. In the main program,  pipe_1, and pipe_2 are defined:

if __name__== '__main__':

6. First, process pipe_1 with numbers from 0 to 9:

    pipe_1 = multiprocessing.Pipe(True)
    process_pipe_1 = 
                   multiprocessing.Process
                   (target=create_items, args=(pipe_1,))
    process_pipe_1.start()

7. Then, process pipe_2, which picks up the numbers from pipe_1 and squares them:

    pipe_2 = multiprocessing.Pipe(True)
    process_pipe_2 = 
                   multiprocessing.Process
                   (target=multiply_items, args=(pipe_1, pipe_2,))
    process_pipe_2.start()

8. Close the processes:

    pipe_1[0].close()
    pipe_2[0].close()

9. Print out the results:

    try:
        while True:
            print (pipe_2[1].recv())
    except EOFError:
        print("End")