On Fri, Mar 30, 2018 at 01:29:53PM +0300, Serhiy Storchaka wrote: > 29.03.18 18:06, Terry Reedy пише: > >On 3/28/2018 11:27 AM, Serhiy Storchaka wrote: > >>The optimizer already changes semantic. Non-optimized "if a and True:" > >>would call bool(a) twice, but optimized code calls it only once. > > > >Perhaps Ref 3.3.1 object.__bool__ entry, after " should return False or > >True.", should say something like "Should not have side-effects, as > >redundant bool calls may be optimized away (bool(bool(ob)) should have > >the same result as bool(ob))." > > Do you meant that it should be idempotent operation? Because > bool(bool(ob)) always have the same result as bool(ob)) if bool(ob) > returns True or False.
Assuming that bool is the built-in, and hasn't been shadowed or monkey-patched. -- Steve _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
