I once had a use case where I wrapped a callback based library (Amazon's S3 library I think) call to instead return an iterator. Couldn't do that with only a ge

I once had a use case where I wrapped a callback based library (Amazon's S3 library I think) call to instead return an iterator. Couldn't do that with only a generator since you can't yield in the callback itself. And it wasnt possible to write a custom iterator class since the library didn't give you back control until it was done. That was the first and only time they were kinda useful to me.