Nick Coghlan added the comment: * the ABC should have a structural __issubclass__ check looking for __enter__ and __exit__ methods
* I agree with making __exit__ abstract (if you don't define it, you don't need a context manager), but does __enter__ need to be abstract? The "return self" default is a good one in many cases where the resource is acquired in __new__ or __init__. * the docs for the ABC are potentially confusing, as they describe what the default implementation does, without making it clear that it's only the default implementation and *permitted* return behaviour is more flexible than that. * I'd prefer not to have contextlib depend on typing, so the generic type definition should probably be in the typing module (similar to the abc-vs-type split for collections). That should also make backporting easier - the ABC can go back via contextlib2, while the generic type can go back via the comment-based typehinting variant ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue25609> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
