[Peter Ludemann] > Does it matter whether the dict order after pop/delete is explicitly > specified, or just specified that it's deterministic?
Any behavior whatsoever becomes essential after it becomes known ;-) For example, dicts as currently ordered easily support LRU (least recently used) purging like so: On access: result = d.pop(key) d[key] = result This moves `key` from wherever it was to the _most_ recently used position. To purge the `numtopurge` least recently used keys (since traversing the dict is always from least-recently to most-recently added): topurge = tuple(itertools.islice(d, numtopurge)) for key in topurge: del d[key] Is it worth guaranteeing that will always "work" (as intended)? Not to me, but I do have code that relies on it now - and we can count on someone else saying it's utterly crucial ;-) _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com