python - Type hint that a function never returns -

python's new type hinting feature allows type hint function returns none...

def some_func() -> none:     pass 

... or leave return type unspecified, pep dictates should cause static analysers assume return type possible:

any function without annotations should treated having general type possible

however, how should type hint function never return? instance, correct way type hint return value of these 2 functions?

def loop_forever():     while true:         print('this function never returns because loops forever')  def always_explode():     raise exception('this function never returns because raises') 

neither specifying -> none nor leaving return type unspecified seems correct in these cases.

even though “pep 484 — type hints” standard mentioned both in question , in answer yet nobody quotes section: the noreturn type covers question.

quote:

the typing module provides special type noreturn annotate functions never return normally. example, function unconditionally raises exception:

from typing import noreturn  def stop() -> noreturn:     raise runtimeerror('no way') 

the section provides examples of wrong usages. though doesn’t cover functions endless loop, in type theory both equally satisfy never returns meaning expressed special type.