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Start your free trialnicolaspeterson
8,569 PointsWhat about using sys.exit instead of break?
In an earlier video, Craig used sys.exit expression to break out of a program. Is there a difference between that and the break code used here?
1 Answer
Chris Freeman
Treehouse Moderator 68,441 PointsHey nicolaspeterson, good question! The semantic difference is break
ends the innermost loop while sys.exit()
exits the entire program.
In Craig’s code, the while
can only be exited when “DONE” is entered. The break
ends the while
loop. After breaking, only the single statement show_list()
is run before the program ends.
Given this is the only way the program ends, the break
could be replaced with:
if new_item == “DONE”:
# break
show_list()
sys.exit()
A downside to this new approach is less readability. The exit is buried inside a loop. Given the purpose of the while
loop is to process input. Adding “exit the program” to its responsibilities muddies the intent of the loop.
If this code block were to be used within another larger program, then it takes away exit control from the larger program which limits this codes ability to be reused. It is much better to let the code end “pythonically” by falling off the end of the module (or by calling a specifically written cleanup before exit function, if needed)
Post back if you need more help. Good luck!!!
nicolaspeterson
8,569 Pointsnicolaspeterson
8,569 PointsClear and concise as always, thank you!