On Tue, Sep 3, 2019 at 5:53 PM Serhiy Storchaka <storch...@gmail.com> wrote: > > 02.09.19 12:24, Chris Angelico пише: > > But the curious difference happens in 3.7. I don't know what changed > > to cause this, but from there on, the list gets built and then > > unpacked. > > This was a side effect of moving the optimization for `x in [a, b]` from > the peepholer to the AST optimizer. >
Ah ha. Thank you. Is it worth trying to reinstate that? On the one hand, there's no reason to build the list, and this technically is a (performance) regression. On the other hand, it's not code people actually write, since you can do the same thing with a tuple and it IS optimized. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
