If you want your script to return values, just do return [1,2,3] from a function wrapping your code but then you'd have to import your script from another script to even have any use for that information:
(again, this would have to be run by a separate Python script and be imported in order to even do any good):
import ...
def main():
# calculate stuff
return [1,2,3]
(This is generally just good for when you want to indicate to a governor what went wrong or simply the number of bugs/rows counted or w/e. Normally 0 is a good exit and >=1 is a bad exit but you could inter-prate them in any way you want to get data out of it)
import sys
# calculate and stuff
sys.exit(100)
And exit with a specific exit code depending on what you want that to tell your governor. I used exit codes when running script by a scheduling and monitoring environment to indicate what has happened.
(os._exit(100) also works, and is a bit more forceful)
If not you'd have to use stdout to communicate with the outside world (like you've described). But that's generally a bad idea unless it's a parser executing your script and can catch whatever it is you're reporting to.
import sys
# calculate stuff
sys.stdout.write('Bugs: 5|Other: 10\n')
sys.stdout.flush()
sys.exit(0)
Are you running your script in a controlled scheduling environment then exit codes are the best way to go.
There's also the option to simply write information to a file, and store the result there.
# calculate
with open('finish.txt', 'wb') as fh:
fh.write(str(5)+'\n')
And pick up the value/result from there. You could even do it in a CSV format for others to read simplistically.
If none of the above work, you can also use network sockets locally *(unix sockets is a great way on nix systems). These are a bit more intricate and deserve their own post/answer. But editing to add it here as it's a good option to communicate between processes. Especially if they should run multiple tasks and return values.