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+--- Thread: best way out of nested loops? (/thread-27124.html)
best way out of nested loops? - Skaperen - May-27-2020
the best and most Pythonic way (in your opinion) to get all the way out of a few nested loops is?
RE: best way out of nested loops? - Knight18 - May-27-2020
Break statement I guess? Or if you're looking for something more drastic, sys.exit?
RE: best way out of nested loops? - buran - May-27-2020
maybe look for way to refactor code without nested loops (can you use itertools.product and break?)?
maybe separate loops in function and return?
RE: best way out of nested loops? - buran - May-27-2020
(May-27-2020, 07:21 AM)Knight18 Wrote: Break statement I guess?just break will break out of the one specific loop, but the question is about nested loops and break out all the way
RE: best way out of nested loops? - jefsummers - May-27-2020
My kludge would be to set a flag in that innermost loop, and then test for the flag when coming out (and break again). This works:
for loop1 in range(10):
for loop2 in range(10):
for loop3 in range(10):
for loop4 in range(10):
x = input('break')
flag = True
break
if flag:
break
#do other stuff
if flag:
break
#do other stuff
if flag:
break
#do more other stuff
RE: best way out of nested loops? - DeaD_EyE - May-27-2020
@jefsummers your solution is a candidate for refactoring.
def loop():
for i in range(10):
for j in range(10):
if i*j > 10:
return i, jJust put everything in a function, return if the condition is fulfilled.If tasks afterwards are necessary, you could work with the return value of the loop function.
RE: best way out of nested loops? - deanhystad - May-28-2020
I would try to flatten the logic if I could. Failing that I would try to "return" out. Failing that I would raise an exception.
RE: best way out of nested loops? - Skaperen - May-30-2020
i like the function idea. but that has the context problem where you might need to pass lots of data. that is where refactoring is needed. i think raising an exception is a kludge. exceptions have a purpose and this is not it. still, it can be a quick way to get at this kind of issue when the cost (such as time) of refactoring is too high.