lesson04_map_async.py

# SuperFastPython.com
# example executing multiple tasks asynchronously
from multiprocessing import Pool

# custom function to be executed in a child process
def task(arg):
 # report a message
 print(f'From another process {arg}', flush=True)
 # return a value
 return arg * 2

# protect the entry point
if __name__ == '__main__':
 # create the multiprocessing pool
 with Pool() as pool:
 # issue multiple tasks to the pool
 async_result = pool.map_async(task, range(10))
 # process return values once all tasks completed
 for result in async_result.get():
 print(result)