Avoid attribute lookups in hot loop

hynek · hynek · commit d691a6d3820d · 2025-09-28T15:40:59.000+02:00
diff --git a/src/attr/_make.py b/src/attr/_make.py
@@ -437,11 +437,12 @@ def _transform_attrs(
         )
 
     fca = Attribute.from_counting_attr
+    no = ClassProps.KeywordOnly.NO
     own_attrs = [
         fca(
             attr_name,
             ca,
-            kw_only is not ClassProps.KeywordOnly.NO,
+            kw_only is not no,
             anns.get(attr_name),
         )
         for attr_name, ca in ca_list

Original file line number	Diff line number	Diff line change
`@@ -437,11 +437,12 @@ def _transform_attrs(`
`437`	`437`	`)`
`438`	`438`
`439`	`439`	`fca = Attribute.from_counting_attr`
	`440`	`+ no = ClassProps.KeywordOnly.NO`
`440`	`441`	`own_attrs = [`
`441`	`442`	`fca(`
`442`	`443`	`attr_name,`
`443`	`444`	`ca,`
`444`		`- kw_only is not ClassProps.KeywordOnly.NO,`
	`445`	`+ kw_only is not no,`
`445`	`446`	`anns.get(attr_name),`
`446`	`447`	`)`
`447`	`448`	`for attr_name, ca in ca_list`