Re: [Python-Dev] Subtle difference between f-strings and str.format()

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))." -- Terry Jan Reedy