PEP 572: Python assignment expressions has been accepted

Re:PEP 572: Python assignment expressions has been accepted by est on Tuesday July 03, 2018 @09:09AM (#17449827)

well, that looks easy.

    m = re.match(r1, s) or re.match(r2, s)
    o = m.group(1) if m else None

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Re:PEP 572: Python assignment expressions has been accepted by cup-of-tea on Tuesday July 03, 2018 @09:20AM (#17449896)

I made a mistake in my question. The arguments to group shouldn't have been the same. What I want to get at is when the two branches are completely different code.

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Re:PEP 572: Python assignment expressions has been accepted by est on Tuesday July 03, 2018 @09:04PM (#17454693)

I think it's a case where PEP 572 tries to fix bad library design.

re.match shouldn't return None at all. I often write helper functions like:

    matcher = lambda r, s: getattr(re.match(r, s), 'group', lambda i: '')
    o = matcher(r1, s)(1) or matcher(r2, s)(3)

here matcher have a fixed, static return type, string.

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