On 2023-03-27 at 18:25:01 -0700, Travis Griggs <travisgri...@gmail.com> wrote:
> "Deques support thread-safe, memory efficient appends and pops from > either side of the deque with approximately the same O(1) performance > in either direction.” > (https://docs.python.org/3.11/library/collections.html?highlight=deque#collections.deque) [...] > I guess this surprised me. When I see “thread safe”, I don’t expect to > get errors. Even without threads, mutating a collection while iterating over it usually results in bad things happening. $ python Python 3.10.10 (main, Mar 5 2023, 22:26:53) [GCC 12.2.1 20230201] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import collections >>> x = collections.deque() >>> x.append(44) >>> x.append(55) >>> x.append(66) >>> x.append(77) >>> x deque([44, 55, 66, 77]) >>> for y in x: x.pop() 77 Traceback (most recent call last): File "<stdin>", line 1, in <module> RuntimeError: deque mutated during iteration Concurrency just increases the likeliness of mutating while iterating. -- https://mail.python.org/mailman/listinfo/python-list
