[Fix] Fix get class attribute from a string (#1345)

Author: HAOCHENYE

mmengine/utils/misc.py

@@ -532,11 +532,12 @@ def get_object_from_string(obj_name: str):
             return None
 
     # get class or attribute from module
+    obj = module
     while True:
         try:
-            obj_cls = getattr(module, part)
+            obj = getattr(obj, part)
             part = next(parts)
         except StopIteration:
-            return obj_cls
+            return obj
         except AttributeError:
             return None

tests/test_utils/test_misc.py

@@ -336,3 +336,5 @@ def test_locate():
     assert get_object_from_string('mmengine.model') is model_module
     assert get_object_from_string(
         'mmengine.model.BaseModel') is model_module.BaseModel
+    assert get_object_from_string('mmengine.model.BaseModel.forward') is \
+        model_module.BaseModel.forward