cpython/Misc/NEWS.d/next/Core and Builtins/2019-08-05-14-22-59.bpo-377...

:pep:`572`: As described in the PEP, assignment expressions now raise
:exc:`SyntaxError` when their interaction with comprehension scoping results
in an ambiguous target scope.

The ``TargetScopeError`` subclass originally proposed by the PEP has been
removed in favour of just raising regular syntax errors for the disallowed
cases.
bpo-37757: Disallow PEP 572 cases that expose implementation details (GH-15131) - drop TargetScopeError in favour of raising SyntaxError directly as per the updated PEP 572 - comprehension iteration variables are explicitly local, but named expression targets in comprehensions are nonlocal or global. Raise SyntaxError as specified in PEP 572 - named expression targets in the outermost iterable of a comprehension have an ambiguous target scope. Avoid resolving that question now by raising SyntaxError. PEP 572 originally required this only for cases where the bound name conflicts with the iteration variable in the comprehension, but CPython can't easily restrict the exception to that case (as it doesn't know the target variable names when visiting the outermost iterator expression) 2019-08-25 10:45:40 -03:00			:pep:`572`: As described in the PEP, assignment expressions now raise
			:exc:`SyntaxError` when their interaction with comprehension scoping results
			`in an ambiguous target scope.`

			The ``TargetScopeError`` subclass originally proposed by the PEP has been
			`removed in favour of just raising regular syntax errors for the disallowed`
			`cases.`