Haha, probably. But counterpoints: 1) the walrus operator is stupid 2) the walrus operator is dangerous 3) `(my_dict[val] := my_dict.get(val, [])).append` is

Haha, probably. But counterpoints: 1) the walrus operator is stupid 2) the walrus operator is dangerous 3) `(my_dict[val] := my_dict.get(val, [])).append` is the opposite of simpler compared to `my_dict.setdefault(val, []).append` or (cleanestly) just `my_default_dict.append`