Matthias Bussonnier wrote:
Is it possible to change some of those deprecation from Warn-by-default (but can add a warning filter to make them error) to error-by-default (but can add a filter to make them only warnings).
Yes, although it would be a change to how Python functions. Basically we would need a default warnings filter with either a very specific regex or a new warnings subclass which made silencing warning more opt-out instead of opt-in. But considering the vast amount of discussions we have had about when to even turn on warnings I don't know if this idea will get traction. -Brett
That way it is easy to fix large projects (even w/o modifying the source) in only a couple of lines of codes; and they buy themselves a year or so and remove in 3.10. That way you have a more gradual transition; and a clear signal to project with a last chance to fix issues. And that way can't complained they did not know as they have to opt-in.