add none checking

src/snowflake/snowpark/modin/plugin/extensions/index.py

@@ -93,7 +93,7 @@ def check_and_update_parent_qc_index_names(self, names: list) -> None:
         Update the Index and its parent's index names if the parent's current query compiler matches
         the recorded query compiler (`_parent_qc`).
         """
-        if self._parent is not None and self._parent._query_compiler is self._parent_qc:
+        if self._parent._query_compiler is self._parent_qc:
             new_query_compiler = self._parent_qc.set_index_names(names)
             self._parent._update_inplace(new_query_compiler=new_query_compiler)
             # Update the query compiler after naming operation.
@@ -762,7 +762,8 @@ def name(self, value: Hashable) -> None:
         self._query_compiler = self._query_compiler.set_index_names([value])
         # Update the name of the parent's index only if the parent's current query compiler
         # matches the recorded query compiler.
-        self._parent.check_and_update_parent_qc_index_names([value])
+        if self._parent is not None:
+            self._parent.check_and_update_parent_qc_index_names([value])
 
     def _get_names(self) -> list[Hashable]:
         """
@@ -790,7 +791,8 @@ def _set_names(self, values: list) -> None:
         self._query_compiler = self._query_compiler.set_index_names(values)
         # Update the name of the parent's index only if the parent's current query compiler
         # matches the recorded query compiler.
-        self._parent.check_and_update_parent_qc_index_names(values)
+        if self._parent is not None:
+            self._parent.check_and_update_parent_qc_index_names(values)
 
     names = property(fset=_set_names, fget=_get_names)