Rather than placing the main at the end of the script, we
defined it above (Section 4.5, “The main program”) as a function
main() so that the code can be
presented in top-down order.
The lines below cause
to be called, assuming that
litsource is the main
script. Python sets global variable
__name__ to the string
'__main__' for the outermost script.
# - - - - - e p i l o g u e - - - - - if __name__ == '__main__': main()