[Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part) (original) (raw)
Terry Reedy tjreedy at udel.edu
Mon Jun 25 15:50:34 EDT 2018
- Previous message (by thread): [Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part)
- Next message (by thread): [Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part)
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
On 6/25/2018 8:25 AM, Paul Moore wrote:
On 25 June 2018 at 12:44, Nick Coghlan <ncoghlan at gmail.com> wrote:
Unfortunately, I think the key rationale for (b) is that if you don't do something along those lines, then there's a different strange scoping discrepancy that arises between the non-comprehension forms of container displays and the comprehension forms: I've been mostly ignoring this proposal for a while now, so I'm going to respond here in the context of someone with a bit of an idea of the underlying complexities, but otherwise coming at it as a new proposal.
(NAME := EXPR,) # Binds a local tuple(NAME := EXPR for _ in range(1)) # Doesn't bind a local
Of course not, in local scopes where is it not executed. But it would, in the nested function where the assignment is executed. Ditto for all of the following.
[NAME := EXPR] # Binds a local [NAME := EXPR for _ in range(1)] # Doesn't bind a local list(NAME := EXPR for _ in range(1)) # Doesn't bind a local
{NAME := EXPR} # Binds a local {NAME := EXPR for _ in range(1)} # Doesn't bind a local set(NAME := EXPR for _ in range(1)) # Doesn't bind a local {NAME := EXPR : EXPR2} # Binds a local {NAME := EXPR : EXPR2 for _ in range(1)} # Doesn't bind a local set((NAME := EXPR, EXPR2) for _ in range(1)) # Doesn't bind a local None of those "discrepancies" bother me in the slightest,
Me neither. I pretty much agree with the rest of what Paul said. If we don't want comprehensions to execute in a nested scope, then we should not create one. See my response to Guido for a possible alternative.
-- Terry Jan Reedy
- Previous message (by thread): [Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part)
- Next message (by thread): [Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part)
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]