PyCS/pycs/util/callbacks.py

import warnings


class Callbacks(list):

    def append(self, value):
        assert callable(value), "It only excepts callable values!"

    def __call__(self, *args, **kwargs):

        for callback in self:
            try:
                callback(*args, **kwargs)

            except TypeError as e:
                warnings.warn(f"{callback} failed with arguments {args} and {kwargs}!")
                pass