Pythonic infinite for loop?

Fri Apr 15 03:24:25 EDT 2011

Chris Angelico <rosuav at gmail.com> writes:
That loop will exit at the first gap in the sequence. If that's what
you want, you could try (untested):
 from itertools import takewhile
 seq = takewhile(lambda n: ('Keyword%d'%n) in dct, count(1))
 lst = map(dct.get, seq)
This does 2 lookups per key, which you could avoid by making the code
uglier (untested):
 sentinel = object()
 seq = (dct.get('Keyword%d'%i,sentinel) for i in count(1))
 lst = list(takewhile(lambda x: x != sentinel, seq))