[Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part) (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Wed Jun 27 09:38:54 EDT 2018

Nick Coghlan wrote:

actually made those semantics available as an explicit "parentlocal NAME" declaration ...:

def listcomp(outermostiter): parentlocal item result = [] for x in outermostiter: item = x result.append(x) return result exprresult = listcomp(items)

I'm not sure that's possible. If I understand correctly, part of the definition of "parent local" is that "parent" refers to the nearest enclosing non-comprehension scope, to give the expected result for nested comprehensions. If that's so, then it's impossible to fully decouple its definition from comprehensions.

-- Greg

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