Python concurrency

concurrency.py

import time
from multiprocessing import Process, Pipe

def sleeper(seconds, conn):
	time.sleep(seconds)
	conn.send("Got up after "+str(seconds)+" seconds")
	conn.close()
	print("Processed: "+str(seconds))
	
if __name__ == '__main__':
	# create a list to keep all processes
	processes = []

	# create a list to keep connections
	parent_connections = []
	
	_start = time.time()
	
	for sec in [2,5]:
		# create a pipe for communication
		parent_conn, child_conn = Pipe()
		parent_connections.append(parent_conn)
		# create the process, pass instance and connection
		process = Process(target=sleeper, args=(sec, child_conn,))
		processes.append(process)

	# start all processes
	for process in processes:
		process.start()

	# make sure that all processes have finished
	for process in processes:
		process.join()
	
	for pc in parent_connections:
		print(pc.recv())
	_end = time.time()
	total_time = _end - _start
	print("Total time: "+str(total_time))