Python 3.13 Release News December 2025 __link__ Jun 2026
def is_str_list(obj: object) -> TypeIs[list[str]]: return isinstance(obj, list) and all(isinstance(x, str) for x in obj)
Deep take: Python is admitting that no one understands large systems perfectly. So it becomes a co-investigator, not just a judge. python 3.13 release news december 2025
It allows CPython to run without the Global Interpreter Lock (GIL), enabling true multi-threaded parallelism on multi-core processors. def is_str_list(obj: object) ->
The threading module gains a new Mutex and RWLock in threading.ext . The standard library’s queue is now lock-free under free-threaded builds. Yet the feel of Python changes: it is less a friendly tutor and more a powerful, indifferent engine. TypeIs[list[str]]: return isinstance(obj