I was thinking about "yield from" and how many times I wanted to use the feature, but because of backward compatibilities, I couldn't. It's sad that it may take possibly 5 or 10 years to see this statement being used in real programs... The PEP 380<http://www.python.org/dev/peps/pep-0380/>was proposed while Python3.1 was still alpha or beta and it took two and a half years to be accepted, but once it was, Python3.2 was already released. I don't know if this was proposed before, but why can't Python have an "__experimental__" magic package for this kind of stuff? The __future__ thing already add features that are sure to be included on a future release, but why those that *may *become official have to suffer that much? What if an experimental feature becomes rejected? from __experimental__ import foo DeprecationWarning: "foo" will be removed on Python 4.0 Note that* the idea is not for people to use experimental features* when they appear, but to have a fallback for when the feature becomes official! As side effect, the feature will be more tested and become more mature when released. -- João Bernardo