[$] Python exception groups

Exceptions inPython are a mechanism used to report errors (of an exceptional variety); programs can be and are written to expect and handlecertain types of exceptions using try and except. Butexceptions were originally meant to report a single error event and, thesedays, things are a tad more complicated than that. A recent PythonEnhancement Proposal (PEP) targets adding exception groups, as well as newsyntax to catch and handle the groups.