From c0418160457970c4654ad8d910cd0ad21a02f3f7 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Sun, 1 Oct 2017 19:37:19 -0400
Subject: [PATCH] [3.6] IDLE: make filetypes a tuple constant. (GH-3847)
 (#3848)

Save a bit of code, plus non-tuples get converted anyway to tuples by tkinter for the tk call.
(cherry picked from commit 5961e7c156f90c7f9444ae95b9d3e55114ca2169)
---
 Lib/idlelib/iomenu.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 3414c7b3aff..f9b6907b40c 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -487,11 +487,11 @@ class IOBinding:
     opendialog = None
     savedialog = None
 
-    filetypes = [
+    filetypes = (
         ("Python files", "*.py *.pyw", "TEXT"),
         ("Text files", "*.txt", "TEXT"),
         ("All files", "*"),
-        ]
+        )
 
     defaultextension = '.py' if sys.platform == 'darwin' else ''