The passage in the PEP misleads its readers into believing, that
unpacking in comprehensions is supported. This is not the case, as
presented by the abstract itself:
> This PEP does not include unpacking operators inside list, set and
> dictionary comprehensions although this has not been ruled out for
> future proposals.
(Historically, the PEP originally did propose this, but that part of
the PEP was rejected, and the abstract wasn't completely updated.)