On Fri, Apr 16, 2021 at 9:49 AM Oscar Benjamin <oscar.j.benjamin@gmail.com> wrote:
That said, I agree it is better that this came up before the feature freeze than after the release. And I am willing to accept that the hypothetical future where annotations are not always syntactically expressions (which did not even exist before this week) is less important than backwards compatibility.
Would it be problematic to postpone making __future__.annotations the default?
__future__.annotation is the default since 2020-10-04. https://github.com/python/cpython/commit/044a1048ca93d466965afc027b91a5a9eb9... After that, many changes are made on compiler and other places. So reverting the change is not so simple. And personally, I love static typing but I don't use type hint for performance/memory usage reason. I spend much effort to optimize PEP 563 to minimize type hinting overhead. So it's very sad that if I can not use type hinting when I can drop Python 3.9 support. So if PEP 649 is accepted, I want to use it since Python 3.10. Otherwise, I can not use type hinting even after I dropped Python 3.9 support. But it is up to release manager and steering council. -- Inada Naoki <songofacandy@gmail.com>