Fix group by properties/callable Issue #1241

Author: gumyr

src/build123d/topology/shape_core.py

@@ -2983,10 +2983,17 @@ def key_f(obj):
                     return round(obj.volume, tol_digits)
 
         elif callable(group_by):
-            key_f = group_by
+            raw_key_f = group_by
+
+            def key_f(obj):
+                val = raw_key_f(obj)
+                return round(val, tol_digits) if isinstance(val, (int, float)) else val
 
         elif isinstance(group_by, property):
-            key_f = group_by.__get__
+
+            def key_f(obj):
+                val = group_by.__get__(obj)
+                return round(val, tol_digits) if isinstance(val, (int, float)) else val
 
         else:
             raise ValueError(f"Unsupported group_by function: {group_by}")

tests/test_direct_api/test_group_by.py

@@ -30,7 +30,8 @@
 import unittest
 
 from build123d.geometry import Axis
-from build123d.topology import Solid
+from build123d.topology import Edge, Solid
+from build123d.objects_curve import CenterArc
 
 
 class TestGroupBy(unittest.TestCase):
@@ -64,6 +65,24 @@ def test_pp(self):
             "[[Vertex(0.0, 0.0, 0.0), Vertex(0.0, 1.0, 0.0), Vertex(1.0, 0.0, 0.0), Vertex(1.0, 1.0, 0.0)], [Vertex(0.0, 0.0, 1.0), Vertex(0.0, 1.0, 1.0), Vertex(1.0, 0.0, 1.0), Vertex(1.0, 1.0, 1.0)]]",
         )
 
+    def test_properties(self):
+
+        c1 = CenterArc((-5, 0), 2, 0, 360)
+        c2 = CenterArc((5, 0), 4, 0, 360)
+        lines = Edge.make_constrained_lines(c1, c2)
+        longest_lines = lines.group_by(Edge.length)[-1]
+        self.assertEqual(len(longest_lines), 2)
+
+    def test_callable(self):
+        def edge_length(e: Edge) -> float:
+            return e.length
+
+        c1 = CenterArc((-5, 0), 2, 0, 360)
+        c2 = CenterArc((5, 0), 4, 0, 360)
+        lines = Edge.make_constrained_lines(c1, c2)
+        longest_lines = lines.group_by(edge_length)[-1]
+        self.assertEqual(len(longest_lines), 2)
+
 
 if __name__ == "__main__":
     unittest.main()