Issue #13491.

Issue #13491.

Issue #14159: Fix the len() of weak containers (WeakSet, WeakKeyDictionary, WeakValueDictionary) to return a better approximation when some objects are dead or dying.
Moreover, the implementation is now O(1) rather than O(n).
Thanks to Yury Selivanov for reporting.

Issue #14159: Fix the len() of weak containers (WeakSet, WeakKeyDictionary, WeakValueDictionary) to return a better approximation when some objects are dead or dying.
Moreover, the implementation is now O(1) rather than O(n).
Thanks to Yury Selivanov for reporting.

the os module.

object.h have changed.

#10713: Improve documentation for \b and \B and add a few tests.  Initial patch and tests by Martin Pool.

(Doc only.)

Patch by Mikhail Novikov.

Patch by Mikhail Novikov.