These examples (and the _When creating an instance..._ paragraph above) seem like they're examples for the person who's going to be using the factories module. So I think they belong in the module docstring, rather than in the docstring of a private function.

On the other hand _The user name can be passed on the context['user'] property to the action function_ seems like an instruction for the person writing a new factory about how they should use the `_get_action_user_name()` helper function, so that does belong in the docstring of the function. (But I think it could be clearer, maybe give an example.)