treatment of this module in this book for more detailsrefer to the python library manual herewe turn next to handful of additional program launching tools and wrap up of this other ways to start programs we've seen variety of ways to launch programs in this book so far--from the os forkexec combination on unixto portable shell command-line launchers like os systemos popenand subprocessto the portable multiprocessing module options of the last section there are still other ways to start programs in the python standard librarysome of which are more platform neutral or obscure than others this section wraps up this with quick tour through this set the os spawn calls the os spawnv and os spawnve calls were originally introduced to launch programs on windowsmuch like fork/exec call combination on unix-like platforms todaythese calls work on both windows and unix-like systemsand additional variants have been added to parrot os exec in recent versions of pythonthe portable subprocess module has started to supersede these calls in factpython' library manual includes note stating that this module has more powerful and equivalent tools and should be preferred to os spawn calls moreoverthe newer multiprocessing module can achieve similarly portable results today when combined with os exec callsas we saw earlier stillthe os spawn calls continue to work as advertised and may appear in python code you encounter the os spawn family of calls execute program named by command line in new processon both windows and unix-like systems in basic operationthey are similar to the fork/exec call combination on unix and can be used as alternatives to the system and popen calls we've already learned in the following interactionfor instancewe start python program with command line in two traditional ways (the second also reads its output) :\pp \system\processespython print(open('makewords py'read()print('spam'print('eggs'print('ham'import os os system('python makewords py'spam eggs ham parallel system tools