Paul Ganssle <p.gans...@gmail.com> added the comment:
One other thing I might mention here is that I did explore the idea of storing this cache on the tzinfo implementation itself, but it is problematic for a number of reasons: 1. It would either need to use some sort of expiring cache (lru, ttl) or require a great deal of memory, greatly reducing the utility - the proposed implementation requires no additional memory. 2. Because the implementation of datetime.__hash__ invokes utcoffset(), it is impossible to implement utcoffset in terms of a dictionary of tz-aware datetimes. This means that you need to construct a new, naive datetime, which is a fairly slow operation and really puts a damper in the utility of the cache. If I were designing this from scratch, I would probably implement it differently, but I think this approach is pretty close to ideal given the constraints of backwards compatibility. ---------- nosy: +belopolsky, lemburg, vstinner _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue35723> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
