use comprehension instead of map

randolf-scholz · randolf-scholz · commit d8a6f94c15ca · 2025-08-11T14:37:40.000+02:00
diff --git a/mypy/typeops.py b/mypy/typeops.py
@@ -603,7 +603,7 @@ def make_simplified_union(
         simplified_set = try_contracting_literals_in_union(simplified_set)
 
     # Step 5: Combine Literals and Instances with LKVs, e.g. Literal[1]?, Literal[1] -> Literal[1]?
-    proper_items: list[ProperType] = list(map(get_proper_type, simplified_set))
+    proper_items: list[ProperType] = [get_proper_type(t) for t in simplified_set]
     last_known_values: list[LiteralType | None] = [
         p_t.last_known_value if isinstance(p_t, Instance) else None for p_t in proper_items
     ]

Original file line number	Diff line number	Diff line change
`@@ -603,7 +603,7 @@ def make_simplified_union(`
`603`	`603`	`simplified_set = try_contracting_literals_in_union(simplified_set)`
`604`	`604`
`605`	`605`	`# Step 5: Combine Literals and Instances with LKVs, e.g. Literal[1]?, Literal[1] -> Literal[1]?`
`606`		`- proper_items: list[ProperType] = list(map(get_proper_type, simplified_set))`
	`606`	`+ proper_items: list[ProperType] = [get_proper_type(t) for t in simplified_set]`
`607`	`607`	`last_known_values: list[LiteralType \| None] = [`
`608`	`608`	`p_t.last_known_value if isinstance(p_t, Instance) else None for p_t in proper_items`
`609`	`609`	`]`