[$] The return of Python dictionary "addition"

Back in March, we looked at a discussionand Python Enhancement Proposal (PEP) for a new dictionary "addition"operator forPython. The discussion back then was lively and voluminous, but the PEP needed someupdates and enhancements in order to proceed. That work has now been doneand a postabout the revisedPEP to the python-ideas mailing list has set off another mega-thread.