gh-144957: Add test for lazy imports with __getattr__

Lib/test/test_import/data/lazy_imports/module_with_getattr.py

@@ -0,0 +1,7 @@
+"""Test module with __getattr__ for gh-144957."""
+
+def __getattr__(name):
+    """Provide dynamic attributes."""
+    if name == "dynamic_attr":
+        return "from_getattr"
+    raise AttributeError(f"module has no attribute {name!r}")

Lib/test/test_import/test_lazy_imports.py

@@ -85,6 +85,23 @@ def test_basic_used(self):
         import test.test_import.data.lazy_imports.basic_used
         self.assertIn("test.test_import.data.lazy_imports.basic2", sys.modules)
 
+    def test_lazy_import_with_getattr(self):
+        """Lazy imports work with module __getattr__ (gh-144957)."""
+        code = textwrap.dedent("""
+            import sys
+            sys.set_lazy_imports("normal")
+            lazy from test.test_import.data.lazy_imports.module_with_getattr import dynamic_attr
+            assert dynamic_attr == "from_getattr"
+            print("OK")
+        """)
+        result = subprocess.run(
+            [sys.executable, "-c", code],
+            capture_output=True,
+            text=True
+        )
+        self.assertEqual(result.returncode, 0, result.stderr)
+        self.assertIn("OK", result.stdout)
+
 
 class GlobalLazyImportModeTests(unittest.TestCase):
     """Tests for sys.set_lazy_imports() global mode control."""

Python/ceval.c

@@ -3084,6 +3084,24 @@ _PyEval_ImportFrom(PyThreadState *tstate, PyObject *v, PyObject *name)
     PyObject *fullmodname, *mod_name, *origin, *mod_name_or_unknown, *errmsg, *spec;
 
     if (PyObject_GetOptionalAttr(v, name, &x) != 0) {
+        // gh-144957: If we got a lazy import object, the module might have
+        // __getattr__ that should be tried first
+        if (x != NULL && PyLazyImport_CheckExact(x)) {
+            PyObject *getattr_func;
+            if (PyObject_GetOptionalAttr(v, &_Py_ID(__getattr__), &getattr_func) < 0) {
+                Py_DECREF(x);
+                return NULL;
+            }
+            if (getattr_func != NULL) {
+                PyObject *result = PyObject_CallOneArg(getattr_func, name);
+                Py_DECREF(getattr_func);
+                if (result != NULL) {
+                    Py_DECREF(x);
+                    return result;
+                }
+                PyErr_Clear();
+            }
+        }
         return x;
     }
     /* Issue #17636: in case this failed because of a circular relative