Jan. 17, 2022
4:27 p.m.
Earlier today in https://bugs.python.org/issue46393, Serhiy Storchaka wrote: As Steven have noted the compiler-time optimization is not applicable here because name frozenset is resolved at run-time. In these cases where a set of constants can be replaced with a frozenset of constants (in "x in {1,2,3}" and in "for x in {1,2,3}") the compiler does it. And I don't think there is an issue which is worth changing the language. Creating a frozenset of constants is pretty rare, and it is even more rare in tight loops. The most common cases (which are pretty rare anyway) are already covered. -- Jonathan