Sorry, for PEP feedback it's best to use this issue in the typing tracker: https://github.com/python/typing/issues/189 (the issue I linked to was in the mypy tracker).
On Mon, Mar 21, 2016 at 9:15 AM, Guido van Rossum <gu...@python.org> wrote: > Here's one more thing we'd like to add to PEP 484. The description is > best gleaned from the issue, in particular > https://github.com/python/mypy/issues/1284#issuecomment-199021176 and > following (we're going with option (A)). > > Really brief example: > > from typing import NewType > UserId = NewType('UserId', int) > > Now to the type checker UserId is a new type that's compatible with > int, but converting an int to a UserId requires a special cast form, > UserId(x). At runtime UserId instances are just ints (not a subclass!) > and UserId() is a dummy function that just returns its argument. > > For use cases see the issue. Also send feedback there please. > > -- > --Guido van Rossum (python.org/~guido) -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
