fix [use hasattr("cv2", "name") ,but first param is 'character string',

resulting in an error in the judgment condition]

modules/python/package/cv2/__init__.py

@@ -33,7 +33,7 @@ def __load_extra_py_code_for_module(base, name, enable_debug_print=False):
         # Extension doesn't contain extra py code
         return False
 
-    if not hasattr(base, name):
+    if base in sys.modules and not hasattr(sys.modules[base], name):
         setattr(sys.modules[base], name, py_module)
     sys.modules[export_module_name] = py_module
     # If it is C extension module it is already loaded by cv2 package