bpo-32856: Optimize the idiom for assignment in comprehensions. by serhiy-storchaka · Pull Request #5695 · python/cpython

bpo-32856: Optimize the idiom for assignment in comprehensions. by serhiy-storchaka · Pull Request #5695 · python/cpython

Now `for y in [expr]` in comprehensions is so fast as a simple
assignment `y = expr`.

serhiy-storchaka changed the title ~~bpo-32856: Optimiz the idiom for assignment in comprehensions.~~ bpo-32856: Optimize the idiom for assignment in comprehensions.

		break;
		case Tuple_kind:
		elts = gen->iter->v.Tuple.elts;
		break;

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How about we handle for x in {a} too?

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This will change the behavior if a is not hashable.

		@@ -0,0 +1,3 @@
		Optimized the idiom for assignment a temporary variable in comprehensions.
		Now ``for y in [expr]`` in comprehensions is so fast as a simple assignment
		``y = expr``.

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Please update the NEWS entry with some benchmark results.

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I'm not sure what should I provide. The optimized code always is the part of complex comprehension expression.

		compile("{x: y for y, x in ((1, 2), (3, 4))} += 5", "<test>",
		"exec")

		def test_assignment_idiom_in_comprehesions(self):

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Typo: comprehesions

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Fixed.