How to do this in Python? - A "gotcha"

S Arrowsmith sion at paintbox.UUCP
Wed Mar 18 17:23:05 CET 2009

Jim Garrison  <jhg at> wrote:
>It's a shame the iter(o,sentinel) builtin does the
>comparison itself, instead of being defined as iter(callable,callable)
>where the second argument implements the termination test and returns a
>boolean.  This would seem to add much more generality... is
>it worthy of a PEP?

class sentinel:
    def __eq__(self, other):
        return termination_test()

for x in iter(callable, sentinel()):

Writing a sensible sentinel.__init__ is left as an exercise....


   under construction

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