bpo-33987: IDLE - use ttk Frame for ttk widgets (GH-11395)

diff --git a/Lib/idlelib/autocomplete_w.py b/Lib/idlelib/autocomplete_w.py
index 9e0d336..7994bc0 100644
--- a/Lib/idlelib/autocomplete_w.py
+++ b/Lib/idlelib/autocomplete_w.py
@@ -4,7 +4,7 @@
 import platform
 
 from tkinter import *
-from tkinter.ttk import Scrollbar
+from tkinter.ttk import Frame, Scrollbar
 
 from idlelib.autocomplete import COMPLETE_FILES, COMPLETE_ATTRIBUTES
 from idlelib.multicall import MC_SHIFT