Python for-else relationship [duplicate]

Question

I can run the below python script without errors.

for n in range(3):
    print n
else:
    print "done"

But I am puzzled about the else without a matching if.
It does not make sense.
Can some one explain why this works ?

Paraphrasing Raymond Hettinger, "if we had just called it nobreak, nobody would ever be surprised by it." — roippi
– roippi, Commented Aug 8, 2013 at 2:27

Ignacio Vazquez-Abrams · Accepted Answer · 2013-08-08 02:25:21Z

7

The else clause of for and while only executes if the loop exits normally, i.e. break is never run.

for i in range(20):
  print i
  if i == 3:
    break
else:
  print 'HAHA!'

And the else clause of try only executes if no exception happened.

try:
  a = 1 / 2
except ZeroDivisionError:
  do_something()
else:
  print '/golfclap'

answered Aug 8, 2013 at 2:25

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1 Comment

+1 for expanding on the original question by showing how it is used with try

jh314 · Accepted Answer · 2013-08-08 02:25:37Z

3

The body of the else is executed after the for loop is done, but only if the for loop didn't terminate early by break statements.

answered Aug 8, 2013 at 2:25

jh314

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