Issue #27891: Consistently group and sort imports within idlelib modules.
diff --git a/Lib/idlelib/tree.py b/Lib/idlelib/tree.py
index 04e0734..292ce36 100644
--- a/Lib/idlelib/tree.py
+++ b/Lib/idlelib/tree.py
@@ -15,10 +15,12 @@
 # - optimize tree redraw after expand of subnode
 
 import os
+
 from tkinter import *
 from tkinter.ttk import Scrollbar
-from idlelib import zoomheight
+
 from idlelib.config import idleConf
+from idlelib import zoomheight
 
 ICONDIR = "Icons"