Implement GetAttrVariable.as_python_constant() (#134216)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/134216
Approved by: https://github.com/amjames, https://github.com/williamwen42

test/dynamo/test_misc.py

@@ -11333,6 +11333,29 @@ fn
         self.assertEqual(r.y, torch.ones(2, 2) + 1)
         self.assertEqual(cnts.frame_count, 1)
 
+    def test_getattrvariable_as_python_constant(self):
+        from torch._dynamo.variables.misc import GetAttrVariable
+
+        @torch.compile(backend="eager")
+        def fn(x, rand1):
+            random.Random().setstate(rand1.getstate())
+            return x + rand1.random()
+
+        def get_rng():
+            rand1 = random.Random(1)
+            orig_random = rand1.random
+            rand1.random = lambda: orig_random()
+            return rand1
+
+        x = torch.randn(3, 3)
+        expected = fn.__wrapped__(x, get_rng())
+
+        with patch.object(GetAttrVariable, "as_python_constant", autospec=True) as po:
+            actual = fn(x, get_rng())
+
+        self.assertEqual(expected, actual)
+        self.assertGreater(po.call_count, 0)
+
 
 class TestTracer(JitTestCase):
     def test_jit_save(self):

torch/_dynamo/variables/misc.py

@@ -1003,6 +1003,13 @@ class GetAttrVariable(VariableTracker):
     def as_proxy(self):
         return GetAttrVariable.create_getattr_proxy(self.obj.as_proxy(), self.name)
 
+    def as_python_constant(self):
+        constant = self.obj.as_python_constant()
+        try:
+            return getattr(constant, self.name)
+        except AttributeError:
+            raise NotImplementedError(f"{self} is not a constant") from None
+
     def const_getattr(self, tx: "InstructionTranslator", name):
         if not isinstance(self.obj, variables.NNModuleVariable):
             raise NotImplementedError