Python multiprocessing daemon
By default, the main program will not exit until all the child processes have exited. Sometimes, however, we need to start some process that continue running without blocking the exit of the main program. In order to realize this , we can set the daemon mode of a process on. By default, it is off.
One difference between multithreading and multiprocessing is the extra protection for using __main__. Wrapping the main part of the application in a check for __main__ ensures that it is not run recursively in each child as the module is imported.