diff --git a/imperative/python/src/ops.cpp b/imperative/python/src/ops.cpp
index c1790eade59ebdc35ffad0cfbb076f72d7df08d0..06100741e50698827c3e9df4e9333c98b38ec9c9 100644
--- a/imperative/python/src/ops.cpp
+++ b/imperative/python/src/ops.cpp
@@ -33,6 +33,18 @@ auto normalize_enum(const std::string& in) {
 }
 } // anonymous namespace
 
+#define CATCH_ALL(RETVAL) \
+    catch(py::error_already_set& e) { \
+        e.restore(); \
+        return RETVAL; \
+    } catch(py::builtin_exception& e) { \
+        e.set_error(); \
+        return RETVAL; \
+    } catch(std::exception& e) { \
+        PyErr_SetString(PyExc_RuntimeError, e.what()); \
+        return RETVAL; \
+    } \
+
 namespace {
 #define PyOp(name) Py##name
 #define PyOpType(name) PyOp(name)::py_type
@@ -99,14 +111,6 @@ PyObject* py_get_generic_impl(PyObject* obj, void* /* closure */) {
 #define py_get_generic(name, attr) \
     py_get_generic_impl<PyOp(name), decltype(std::declval<name>().attr), &name::attr>
 
-template<typename T>
-PyObject* py_get_scope_impl(PyObject* obj, void* /* closure */) {
-    // T: PyOpXXX  inst(): return XXX in opdef.h.inl
-    auto& op = reinterpret_cast<T*>(obj)->inst();
-    return pyobj_convert_generic<std::string>::to(op.scope());
-}
-#define py_get_scope(class) py_get_scope_impl<PyOp(class)>
-
 template<typename T, typename U, U T::Ty::*attr>
 int py_set_generic_impl(PyObject* obj, PyObject* value, void* /* closure */) {
     if (value == NULL) {
@@ -116,51 +120,46 @@ int py_set_generic_impl(PyObject* obj, PyObject* value, void* /* closure */) {
     auto& op = reinterpret_cast<T*>(obj)->inst();
     try {
         op.*attr = pyobj_convert_generic<U>::from(value);
-        return 0;
-    } catch(py::error_already_set& e) {
-        e.restore();
-    } catch(py::builtin_exception& e) {
-        e.set_error();
-    } catch(...) {
-        PyErr_SetString(PyExc_RuntimeError, "Unknown Error");
-    }
-    return -1;
+    } CATCH_ALL(-1)
+    return 0;
 }
 #define py_set_generic(name, attr) \
     py_set_generic_impl<PyOp(name), decltype(std::declval<name>().attr), &name::attr>
 
-template<typename T>
-int py_set_scope_impl(PyObject* obj, PyObject* value, void* /* closure */) {
-    if (value == NULL) {
-        PyErr_SetString(PyExc_TypeError, "Cannot delete the attribute");
-        return -1;
-    }
-    auto& op = reinterpret_cast<T*>(obj)->inst();
-    try {
-        op.set_scope(pyobj_convert_generic<std::string>::from(value));
-        return 0;
-    } catch(py::error_already_set& e) {
-        e.restore();
-    } catch(py::builtin_exception& e) {
-        e.set_error();
-    } catch(...) {
-        PyErr_SetString(PyExc_RuntimeError, "Unknown Error");
-    }
-    return -1;
-}
-#define py_set_scope(class) py_set_scope_impl<PyOp(class)>
-
 struct PyOpDef {
     PyObject_HEAD
     std::shared_ptr<OpDef> op;
     static PyTypeObject py_type;
     static std::unordered_map<mgb::Typeinfo*, PyTypeObject*> ctype2pytype;
+    static PyGetSetDef py_getsetters[];
     static Py_hash_t tp_hash(PyObject *obj);
     static PyObject* tp_richcompare(PyObject *self, PyObject *other, int op);
 };
 PyTypeObject PyOpType(OpDef);
 std::unordered_map<mgb::Typeinfo*, PyTypeObject*> PyOp(OpDef)::ctype2pytype;
 
+PyObject* py_get_scope(PyObject* obj, void* /* closure */) {
+    return pyobj_convert_generic<std::string>::to(
+        reinterpret_cast<PyOp(OpDef)*>(obj)->op->scope());
+}
+
+int py_set_scope(PyObject* obj, PyObject* value, void* /* closure */) {
+    if (value == NULL) {
+        PyErr_SetString(PyExc_TypeError, "Cannot delete the attribute");
+        return -1;
+    }
+    try {
+        reinterpret_cast<PyOp(OpDef)*>(obj)->op
+            ->set_scope(pyobj_convert_generic<std::string>::from(value));
+    } CATCH_ALL(-1)
+    return 0;
+}
+
+PyGetSetDef PyOp(OpDef)::py_getsetters[] = {
+    {const_cast<char*>("scope"), py_get_scope, py_set_scope, "scope", NULL},
+    {NULL}
+};
+
 Py_hash_t PyOp(OpDef)::tp_hash(PyObject *obj) {
     return static_cast<Py_hash_t>(
         reinterpret_cast<PyOp(OpDef)*>(obj)->op->hash());
@@ -225,6 +224,7 @@ struct pyobj_convert_generic<T,
 };
 
 void _init_py_op_def(py::module m) {
+    using py_op = PyOp(OpDef);
     auto& py_type = PyOpType(OpDef);
     py_type = {PyVarObject_HEAD_INIT(NULL, 0)};
     py_type.tp_name = "megengine.core._imperative_rt.OpDef";
@@ -234,6 +234,7 @@ void _init_py_op_def(py::module m) {
     py_type.tp_base = &PyBaseObject_Type;
     py_type.tp_hash = PyOp(OpDef)::tp_hash;
     py_type.tp_richcompare = PyOp(OpDef)::tp_richcompare;
+    py_type.tp_getset = py_op::py_getsetters;
     mgb_assert(PyType_Ready(&py_type) >= 0);
     m.add_object("OpDef", reinterpret_cast<PyObject*>(&py_type));
 }
@@ -309,6 +310,8 @@ void _init_py_op_base(py::module m) {
 // auto generated opdefs
 #include "opdef.cpy.inl"
 
+#undef CATCH_ALL
+
 } // anonymous namespace
 
 namespace PYBIND11_NAMESPACE {
diff --git a/imperative/tablegen/autogen.cpp b/imperative/tablegen/autogen.cpp
index eec1a5ec21cc2880b03205d77279beb96989882c..5e2b137a1c7050e0487783a49d08b4bcccd4b260 100644
--- a/imperative/tablegen/autogen.cpp
+++ b/imperative/tablegen/autogen.cpp
@@ -485,52 +485,44 @@ EnumWrapper<{0}::{1}>::type2str = {{
             className, i.name));
     }
 
-    getsetters.push_back(formatv(
-        "{{\"scope\", py_get_scope({0}), py_set_scope({0}), \"scope\", NULL},",
-        className));
-
     // generate tp_init
     std::string initBody;
     if (!op.getMgbAttributes().empty()) {
         initBody += "static const char* kwlist[] = {";
+
+        std::vector<llvm::StringRef> attr_name_list;
         llvm::for_each(op.getMgbAttributes(), [&](auto&& attr) {
-            initBody += formatv("\"{0}\", ", attr.name);
+            attr_name_list.push_back(attr.name);
+        });
+        attr_name_list.push_back("scope");
+
+        llvm::for_each(attr_name_list, [&](auto&& attr) {
+            initBody += formatv("\"{0}\", ", attr);
         });
-        initBody += "\"scope\", ";
         initBody += "NULL};\n";
         initBody += "    PyObject ";
-        std::vector<std::string> attrs;
-        llvm::for_each(op.getMgbAttributes(), [&](auto&& attr) {
-            attrs.push_back(formatv("*{0} = NULL", attr.name));
+        std::vector<std::string> attr_init;
+        llvm::for_each(attr_name_list, [&](auto&& attr) {
+            attr_init.push_back(formatv("*{0} = NULL", attr));
         });
-        initBody += llvm::join(attrs, ", ") + ";\n";
-        initBody += "    PyObject *scope = NULL;\n";
+        initBody += llvm::join(attr_init, ", ") + ";\n";
         initBody += "    if (!PyArg_ParseTupleAndKeywords(args, kwds, \"|";
         // an extra slot created for name
-        initBody += std::string(op.getMgbAttributes().size() + 1, 'O');
+        initBody += std::string(attr_name_list.size(), 'O');
         initBody += "\", const_cast<char**>(kwlist)";
-        llvm::for_each(op.getMgbAttributes(), [&](auto&& attr) {
-            initBody += formatv(", &{0}", attr.name);
+        llvm::for_each(attr_name_list, [&](auto&& attr) {
+            initBody += formatv(", &{0}", attr);
         });
-        initBody += ", &scope";
         initBody += "))\n";
         initBody += "    return -1;\n";
+
         llvm::for_each(op.getMgbAttributes(), [&](auto&& attr) {
             initBody += formatv(R"(
     if ({1}) {{
         try {{
             reinterpret_cast<PyOp({0})*>(self)->inst().{1} =
                 pyobj_convert_generic<decltype({0}::{1})>::from({1});
-        } catch(py::error_already_set& e) {{
-            e.restore();
-            return -1;
-        } catch(py::builtin_exception& e) {{
-            e.set_error();
-            return -1;
-        } catch(...) {{
-            PyErr_SetString(PyExc_RuntimeError, "Unknown Error");
-            return -1;
-        }
+        } CATCH_ALL(-1)
     }
 )", className, attr.name);
         });
@@ -538,18 +530,9 @@ EnumWrapper<{0}::{1}>::type2str = {{
         initBody += formatv(R"(
     if (scope) {{
         try {{
-            reinterpret_cast<PyOp({0})*>(self)->inst().set_scope(
-                pyobj_convert_generic<std::string>::from(scope));
-        } catch(py::error_already_set& e) {{
-            e.restore();
-            return -1;
-        } catch(py::builtin_exception& e) {{
-            e.set_error();
-            return -1;
-        } catch(...) {{
-            PyErr_SetString(PyExc_RuntimeError, "Unknown Error");
-            return -1;
-        }
+            reinterpret_cast<PyOp(OpDef)*>(self)->op
+                ->set_scope(pyobj_convert_generic<std::string>::from(scope));
+        } CATCH_ALL(-1)
     }
 )", className);