[Python-Dev] List copy and clear (was Re: Inconsistent API forsets.Set and build-in set)

[Tim Peters]

[Tim Peters]
>> Or my personal favorite,
>>
>>    while mylist:
>>        del mylist[::2]
>>
>> Then the original index positions with the most consecutive trailing 1
>> bits survive the longest, which is important to avoid ZODB cache bugs
>> <wink>.

[Christos Georgiou]
> This is a joke, hopefully, and in that case, I fell for it.  If not, please
> provide a url with related discussion (for educational purposes :)

Fell for what?  It's certainly true that the code snippet allows the
original index positions with the most consecutive trailing 1 bits to
survive the longest (on the first iteration, all even index positions
(no trailing 1 bits) are deleted, and you don't really need a URL to
figure out what happens on the i'th iteration).  The idea that this is
helpful in avoiding anything's "cache bugs" is purely <wink>-worthy,
though.