From bd2cdae3ce3de8e1ac912a11885fc98f1dc22bb4 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Thu, 14 Oct 2021 17:04:37 +0100
Subject: [PATCH 01/28] bpo-45447: Add syntax highlighting for `.pyi` files in
 IDLE

This commit adds syntax highlighting for `.pyi` files in IDLE.
It also adds an option to open Python stub files in the "File-open" dialogue,
and an option to save a file as a `.pyi` file in the "File-save" dialogue.
---
 Lib/idlelib/README.txt                        |  1 +
 Lib/idlelib/browser.py                        | 17 +++++----
 Lib/idlelib/editor.py                         | 12 +++----
 Lib/idlelib/idle_test/test_iomenu.py          | 18 ++++++++++
 Lib/idlelib/idle_test/test_util.py            | 15 ++++++++
 Lib/idlelib/iomenu.py                         |  1 +
 Lib/idlelib/util.py                           | 36 +++++++++++++++++++
 Misc/ACKS                                     |  1 +
 .../2021-10-14-16-55-03.bpo-45447.FhiH5P.rst  |  2 ++
 9 files changed, 87 insertions(+), 16 deletions(-)
 create mode 100644 Lib/idlelib/idle_test/test_util.py
 create mode 100644 Lib/idlelib/util.py
 create mode 100644 Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst

diff --git a/Lib/idlelib/README.txt b/Lib/idlelib/README.txt
index bc3d978f43f1ad..54a603d59b5b29 100644
--- a/Lib/idlelib/README.txt
+++ b/Lib/idlelib/README.txt
@@ -81,6 +81,7 @@ statusbar.py      # Define status bar for windows (nim).
 tabbedpages.py    # Define tabbed pages widget (nim).
 textview.py       # Define read-only text widget (nim).
 tree.py           # Define tree widget, used in browsers (nim).
+util.py           # Define objects imported elsewhere with no dependencies (nim)
 undo.py           # Manage undo stack.
 windows.py        # Manage window list and define listed top level.
 zoomheight.py     # Zoom window to full height of screen.
diff --git a/Lib/idlelib/browser.py b/Lib/idlelib/browser.py
index 3c3a53a6599a79..1168c49e240c9c 100644
--- a/Lib/idlelib/browser.py
+++ b/Lib/idlelib/browser.py
@@ -13,6 +13,7 @@
 import pyclbr
 import sys
 
+from idlelib.util import is_python_source, is_python_extension
 from idlelib.config import idleConf
 from idlelib import pyshell
 from idlelib.tree import TreeNode, TreeItem, ScrolledCanvas
@@ -76,7 +77,7 @@ def __init__(self, master, path, *, _htest=False, _utest=False):
 
         Instance variables:
             name: Module name.
-            file: Full path and module with .py extension.  Used in
+            file: Full path and module with a valid Python extension. Used in
                 creating ModuleBrowserTreeItem as the rootnode for
                 the tree and subsequently in the children.
         """
@@ -161,21 +162,19 @@ def GetSubList(self):
 
     def OnDoubleClick(self):
         "Open a module in an editor window when double clicked."
-        if os.path.normcase(self.file[-3:]) != ".py":
-            return
-        if not os.path.exists(self.file):
-            return
-        file_open(self.file)
+        if self.IsExpandable() and os.path.exists(self.file):
+            file_open(self.file)
 
     def IsExpandable(self):
-        "Return True if Python (.py) file."
-        return os.path.normcase(self.file[-3:]) == ".py"
+        "Identify whether `self.file` is a valid Python file."
+        # see idlelib.util for currently supported Python extensions.
+        return is_python_source(self.file)
 
     def listchildren(self):
         "Return sequenced classes and functions in the module."
         dir, base = os.path.split(self.file)
         name, ext = os.path.splitext(base)
-        if os.path.normcase(ext) != ".py":
+        if not is_python_extension(os.path.normcase(ext)):
             return []
         try:
             tree = pyclbr.readmodule_ex(name, [dir] + sys.path)
diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index fcc8a3f08ccfe3..b82277b0209f55 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -15,6 +15,7 @@
 from tkinter import simpledialog
 from tkinter import messagebox
 
+import idlelib.util
 from idlelib.config import idleConf
 from idlelib import configdialog
 from idlelib import grep
@@ -754,13 +755,10 @@ def gotoline(self, lineno):
             self.center()
 
     def ispythonsource(self, filename):
-        if not filename or os.path.isdir(filename):
-            return True
-        base, ext = os.path.splitext(os.path.basename(filename))
-        if os.path.normcase(ext) in (".py", ".pyw"):
-            return True
-        line = self.text.get('1.0', '1.0 lineend')
-        return line.startswith('#!') and 'python' in line
+        return idlelib.util.is_python_source(
+            filepath=filename,
+            firstline=self.text.get('1.0', '1.0 lineend')
+        )
 
     def close_hook(self):
         if self.flist:
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 99f40487967124..bb53b53808d9ae 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -44,6 +44,24 @@ def test_fixnewlines_end(self):
         eq(text.get('1.0', 'end-1c'), 'a\n')
         eq(fix(), 'a'+io.eol_convention)
 
+    def check_filetype(self, ext):
+        return any(
+            ext in filetype_tuple[1] for filetype_tuple in self.io.filetypes
+        )
+
+    def test_python_files(self):
+        self.assertTrue(self.check_filetype('*.py'))
+        self.assertTrue(self.check_filetype('*.pyw'))
+
+    def test_python_stub_files(self):
+        self.assertTrue(self.check_filetype('*.pyi'))
+
+    def test_text_files(self):
+        self.assertTrue(self.check_filetype('*.txt'))
+
+    def test_all_files(self):
+        self.assertTrue(self.check_filetype('*'))
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
new file mode 100644
index 00000000000000..246dd8b12d439b
--- /dev/null
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -0,0 +1,15 @@
+"Test constants and functions found in idlelib.util"
+
+import unittest
+from idlelib import util
+
+
+class ExtensionTest(unittest.TestCase):
+    def test_extensions(self):
+        self.assertIn('.pyi', util.PYTHON_EXTENSIONS)
+        self.assertIn('.py', util.PYTHON_EXTENSIONS)
+        self.assertIn('.pyw', util.PYTHON_EXTENSIONS)
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)
diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 5ebf7089fb9abe..57a41182349085 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -349,6 +349,7 @@ def print_window(self, event):
 
     filetypes = (
         ("Python files", "*.py *.pyw", "TEXT"),
+        ("Python stub files", "*.pyi", "TEXT"),
         ("Text files", "*.txt", "TEXT"),
         ("All files", "*"),
         )
diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
new file mode 100644
index 00000000000000..af3714d40472f4
--- /dev/null
+++ b/Lib/idlelib/util.py
@@ -0,0 +1,36 @@
+"""
+Idlelib objects with no external idlelib dependencies
+which are needed in more than one idlelib module.
+
+They are included here because
+    a) they don't particularly belong elsewhere; or
+    b) because inclusion here simplifies the idlelib dependency graph.
+
+TODO:
+    * Python versions (editor and help_about),
+    * tk version and patchlevel (pyshell, help_about, maxos?, editor?),
+    * std streams (pyshell, run),
+    * warning stuff (ditto).
+"""
+from os import path
+
+# PYTHON_EXTENSIONS is used in editor, browser, and iomenu.
+# .pyw is for Windows; .pyi is for stub files.
+PYTHON_EXTENSIONS = frozenset({'.py', '.pyw', '.pyi'})
+
+
+def is_python_extension(extension, is_valid=PYTHON_EXTENSIONS.__contains__):
+    """Identify whether a given string is a valid Python file extension"""
+    return is_valid(extension)
+
+
+def is_python_source(filepath, firstline=None):
+    """Identify whether a given path is valid as a Python module."""
+    if not filepath or path.isdir(filepath):
+        return True
+    base, ext = path.splitext(path.basename(filepath))
+    return is_python_extension(path.normcase(ext)) or all((
+        firstline is not None,
+        firstline.startswith('#!'),
+        'python' in firstline
+    ))
diff --git a/Misc/ACKS b/Misc/ACKS
index 23c92abb4d02a7..204293fa50d9c0 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1885,6 +1885,7 @@ Bob Watson
 Colin Watson
 David Watson
 Aaron Watters
+Alex Waygood
 Henrik Weber
 Leon Weber
 Steve Weber
diff --git a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
new file mode 100644
index 00000000000000..6750e42b145c55
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
@@ -0,0 +1,2 @@
+IDLE now knows that `.pyi` files can only contain valid Python expressions,
+and will apply syntax highlighting accordingly. Patch by Alex Waygood.

From b12399d1772946106e29a75e69cb9bafb9efe388 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 11:36:30 +0100
Subject: [PATCH 02/28] Improve news entry.

Co-authored-by: E-Paine <63801254+E-Paine@users.noreply.github.com>
---
 Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
index 6750e42b145c55..35ccd29487ce13 100644
--- a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
+++ b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
@@ -1,2 +1 @@
-IDLE now knows that `.pyi` files can only contain valid Python expressions,
-and will apply syntax highlighting accordingly. Patch by Alex Waygood.
+IDLE now applies syntax highlighting to `.pyi` files. Patch by Alex Waygood.

From 96d5a8865e409a73929501623e4b1d39ed79e0e4 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 11:37:32 +0100
Subject: [PATCH 03/28] Improve docstring at top of util.py

Co-authored-by: E-Paine <63801254+E-Paine@users.noreply.github.com>
---
 Lib/idlelib/util.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index af3714d40472f4..4f2539c742a32b 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -10,7 +10,7 @@
     * Python versions (editor and help_about),
     * tk version and patchlevel (pyshell, help_about, maxos?, editor?),
     * std streams (pyshell, run),
-    * warning stuff (ditto).
+    * warning stuff (pyshell, run).
 """
 from os import path
 

From eee661edabccb57514fff6597f2e31173df38b1a Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 12:32:34 +0100
Subject: [PATCH 04/28] Improve tests

---
 Lib/idlelib/idle_test/test_iomenu.py | 25 +++++-----
 Lib/idlelib/idle_test/test_util.py   | 68 +++++++++++++++++++++++++++-
 Lib/idlelib/util.py                  | 17 ++++---
 3 files changed, 88 insertions(+), 22 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index bb53b53808d9ae..7f22f664ab87f7 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -1,6 +1,6 @@
 "Test , coverage 17%."
 
-from idlelib import iomenu
+from idlelib import iomenu, util
 import unittest
 from test.support import requires
 from tkinter import Tk
@@ -44,23 +44,24 @@ def test_fixnewlines_end(self):
         eq(text.get('1.0', 'end-1c'), 'a\n')
         eq(fix(), 'a'+io.eol_convention)
 
-    def check_filetype(self, ext):
-        return any(
-            ext in filetype_tuple[1] for filetype_tuple in self.io.filetypes
-        )
 
-    def test_python_files(self):
-        self.assertTrue(self.check_filetype('*.py'))
-        self.assertTrue(self.check_filetype('*.pyw'))
+def _extension_is_in_IOBinding_dot_filetypes(extension):
+    return any(
+        extension in filetype_tuple[1]
+        for filetype_tuple in iomenu.IOBinding.filetypes
+    )
 
-    def test_python_stub_files(self):
-        self.assertTrue(self.check_filetype('*.pyi'))
+
+class FiletypesTest(unittest.TestCase):
+    def test_python_source_files(self):
+        for extension in util.PYTHON_EXTENSIONS:
+            self.assertTrue(_extension_is_in_IOBinding_dot_filetypes(extension))
 
     def test_text_files(self):
-        self.assertTrue(self.check_filetype('*.txt'))
+        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('*.txt'))
 
     def test_all_files(self):
-        self.assertTrue(self.check_filetype('*'))
+        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('*'))
 
 
 if __name__ == '__main__':
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 246dd8b12d439b..09a1eea991a012 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,15 +1,81 @@
 "Test constants and functions found in idlelib.util"
 
 import unittest
+from unittest import mock
 from idlelib import util
 
 
 class ExtensionTest(unittest.TestCase):
-    def test_extensions(self):
+    def test_pyi(self):
         self.assertIn('.pyi', util.PYTHON_EXTENSIONS)
+
+    def test_py(self):
         self.assertIn('.py', util.PYTHON_EXTENSIONS)
+
+    def test_pyw(self):
         self.assertIn('.pyw', util.PYTHON_EXTENSIONS)
 
 
+class IsPythonExtensionTest(unittest.TestCase):    
+    def test_positives(self):
+        for extension in util.PYTHON_EXTENSIONS:
+            self.assertTrue(util.is_python_extension(extension))
+
+    def test_negatives(self):
+        NEGATIVES = '.pyc', '.p', 'py', '.pyy', '..py', '.ppy'
+        for bad_extension in NEGATIVES:
+            self.assertFalse(util.is_python_extension(bad_extension))
+
+
+class IsPythonSourceTest(unittest.TestCase):
+    def test_empty_string_filepath(self):
+        self.assertTrue(util.is_python_source(''))
+
+    def test_directory_filepath(self):
+        with mock.patch('os.path.isdir', return_value=True):
+            self.assertTrue(util.is_python_source('asdfoijf9245-98-$%^&*.json'))
+
+    def test_python_extension(self):
+        with mock.patch('idlelib.util.is_python_extension', return_value=True):
+            self.assertTrue(util.is_python_source('asdfe798723%^&*^%£(.docx'))
+
+    def test_bad_filepath_no_firstline(self):
+        with (
+            mock.patch('os.path.isdir', return_value=False),
+            mock.patch('idlelib.util.is_python_extension', return_value=False)
+        ):
+            self.assertFalse(util.is_python_source('%^*iupoukjcj&)9675889'))
+
+    def test_bad_filepath_good_firstline(self):        
+        with (
+            mock.patch('os.path.isdir', return_value=False),
+            mock.patch('idlelib.util.is_python_extension', return_value=False)
+        ):
+            self.assertTrue(util.is_python_source(
+                'ad^%^&*yoi724)', '#!python'
+            ))
+            self.assertTrue(util.is_python_source(
+                '7890J:IUJjhu435465$£^%£', '#!     python'
+            ))
+            self.assertTrue(util.is_python_source(
+                '$%^&554657jhasfnmnbnnnm', '#!asdfkpoijeqrjiumnbjypythonasdfjlh'
+            ))
+
+    def test_bad_filepath_bad_firstline(self):
+        with (
+            mock.patch('os.path.isdir', return_value=False),
+            mock.patch('idlelib.util.is_python_extension', return_value=False)
+        ):
+            self.assertFalse(util.is_python_source(
+                'tyyuiuoiu', '#python!'
+            ))
+            self.assertFalse(util.is_python_source(
+                '796923568%^&**$', '!#python'
+            ))
+            self.assertFalse(util.is_python_source(
+                '67879iy987kjl87', 'python#!'
+            ))
+
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index 4f2539c742a32b..6ac0512c40d615 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -14,14 +14,13 @@
 """
 from os import path
 
-# PYTHON_EXTENSIONS is used in editor, browser, and iomenu.
 # .pyw is for Windows; .pyi is for stub files.
 PYTHON_EXTENSIONS = frozenset({'.py', '.pyw', '.pyi'})
 
 
-def is_python_extension(extension, is_valid=PYTHON_EXTENSIONS.__contains__):
-    """Identify whether a given string is a valid Python file extension"""
-    return is_valid(extension)
+def is_python_extension(extension, valid_extensions=PYTHON_EXTENSIONS):
+    """Identify whether a given string is a valid Python file extension."""
+    return extension in valid_extensions
 
 
 def is_python_source(filepath, firstline=None):
@@ -29,8 +28,8 @@ def is_python_source(filepath, firstline=None):
     if not filepath or path.isdir(filepath):
         return True
     base, ext = path.splitext(path.basename(filepath))
-    return is_python_extension(path.normcase(ext)) or all((
-        firstline is not None,
-        firstline.startswith('#!'),
-        'python' in firstline
-    ))
+    return is_python_extension(path.normcase(ext)) or (
+        firstline is not None
+        and firstline.startswith('#!')
+        and 'python' in firstline
+    )

From b9ef62ba5340aad75a4baa0a2fff7693fe868273 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 12:58:52 +0100
Subject: [PATCH 05/28] Use keyword arguments in test_util.py

---
 Lib/idlelib/idle_test/test_util.py | 38 ++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 09a1eea991a012..582d742108cd61 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -22,9 +22,11 @@ def test_positives(self):
             self.assertTrue(util.is_python_extension(extension))
 
     def test_negatives(self):
-        NEGATIVES = '.pyc', '.p', 'py', '.pyy', '..py', '.ppy'
-        for bad_extension in NEGATIVES:
-            self.assertFalse(util.is_python_extension(bad_extension))
+        self.assertFalse(util.is_python_extension('.pyc'))
+        self.assertFalse(util.is_python_extension('.p'))
+        self.assertFalse(util.is_python_extension('.pyy'))
+        self.assertFalse(util.is_python_extension('..py'))
+        self.assertFalse(util.is_python_extension('.ppy'))
 
 
 class IsPythonSourceTest(unittest.TestCase):
@@ -33,18 +35,24 @@ def test_empty_string_filepath(self):
 
     def test_directory_filepath(self):
         with mock.patch('os.path.isdir', return_value=True):
-            self.assertTrue(util.is_python_source('asdfoijf9245-98-$%^&*.json'))
+            self.assertTrue(
+                util.is_python_source(filepath='asdfoijf9245-98-$%^&*.json')
+            )
 
     def test_python_extension(self):
         with mock.patch('idlelib.util.is_python_extension', return_value=True):
-            self.assertTrue(util.is_python_source('asdfe798723%^&*^%£(.docx'))
+            self.assertTrue(
+                util.is_python_source(filepath='asdfe798723%^&*^%£(.docx')
+            )
 
     def test_bad_filepath_no_firstline(self):
         with (
             mock.patch('os.path.isdir', return_value=False),
             mock.patch('idlelib.util.is_python_extension', return_value=False)
         ):
-            self.assertFalse(util.is_python_source('%^*iupoukjcj&)9675889'))
+            self.assertFalse(
+                util.is_python_source(filepath='%^*iupoukjcj&)9675889')
+            )
 
     def test_bad_filepath_good_firstline(self):        
         with (
@@ -52,13 +60,16 @@ def test_bad_filepath_good_firstline(self):
             mock.patch('idlelib.util.is_python_extension', return_value=False)
         ):
             self.assertTrue(util.is_python_source(
-                'ad^%^&*yoi724)', '#!python'
+                filepath='ad^%^&*yoi724)',
+                firstline='#!python'
             ))
             self.assertTrue(util.is_python_source(
-                '7890J:IUJjhu435465$£^%£', '#!     python'
+                filepath='7890J:IUJjhu435465$£^%£',
+                firstline='#!     python'
             ))
             self.assertTrue(util.is_python_source(
-                '$%^&554657jhasfnmnbnnnm', '#!asdfkpoijeqrjiumnbjypythonasdfjlh'
+                filepath='$%^&554657jhasfnmnbnnnm',
+                firstline='#!asdfkpoijeqrjiumnbjypythonasdfjlh'
             ))
 
     def test_bad_filepath_bad_firstline(self):
@@ -67,13 +78,16 @@ def test_bad_filepath_bad_firstline(self):
             mock.patch('idlelib.util.is_python_extension', return_value=False)
         ):
             self.assertFalse(util.is_python_source(
-                'tyyuiuoiu', '#python!'
+                filepath='tyyuiuoiu',
+                firstline='#python!'
             ))
             self.assertFalse(util.is_python_source(
-                '796923568%^&**$', '!#python'
+                filepath='796923568%^&**$',
+                firstline='!#python'
             ))
             self.assertFalse(util.is_python_source(
-                '67879iy987kjl87', 'python#!'
+                filepath='67879iy987kjl87',
+                firstline='python#!'
             ))
 
 

From 44fb0f1e7e27bdf44aaa5d8dbe39ae632b4483a1 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 14:10:44 +0100
Subject: [PATCH 06/28] Correct alphabetical order in README.txt...

---
 Lib/idlelib/README.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/idlelib/README.txt b/Lib/idlelib/README.txt
index 54a603d59b5b29..8870fda315e392 100644
--- a/Lib/idlelib/README.txt
+++ b/Lib/idlelib/README.txt
@@ -81,8 +81,8 @@ statusbar.py      # Define status bar for windows (nim).
 tabbedpages.py    # Define tabbed pages widget (nim).
 textview.py       # Define read-only text widget (nim).
 tree.py           # Define tree widget, used in browsers (nim).
-util.py           # Define objects imported elsewhere with no dependencies (nim)
 undo.py           # Manage undo stack.
+util.py           # Define objects imported elsewhere with no dependencies (nim)
 windows.py        # Manage window list and define listed top level.
 zoomheight.py     # Zoom window to full height of screen.
 

From 2d8e0e8cb8ed8f57b025e2bc237a109655b1f64b Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 15 Oct 2021 15:03:58 +0100
Subject: [PATCH 07/28] Update coverage statistics in test files

---
 Lib/idlelib/idle_test/test_browser.py | 2 +-
 Lib/idlelib/idle_test/test_editor.py  | 2 +-
 Lib/idlelib/idle_test/test_iomenu.py  | 2 +-
 Lib/idlelib/idle_test/test_util.py    | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_browser.py b/Lib/idlelib/idle_test/test_browser.py
index 03a50f22ca1e82..cd99a763e0a91b 100644
--- a/Lib/idlelib/idle_test/test_browser.py
+++ b/Lib/idlelib/idle_test/test_browser.py
@@ -1,4 +1,4 @@
-"Test browser, coverage 90%."
+"Test browser, coverage 81%."
 
 from idlelib import browser
 from test.support import requires
diff --git a/Lib/idlelib/idle_test/test_editor.py b/Lib/idlelib/idle_test/test_editor.py
index 8665d680c0118f..20a3bd04ee7e75 100644
--- a/Lib/idlelib/idle_test/test_editor.py
+++ b/Lib/idlelib/idle_test/test_editor.py
@@ -1,4 +1,4 @@
-"Test editor, coverage 35%."
+"Test editor, coverage 54%."
 
 from idlelib import editor
 import unittest
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 7f22f664ab87f7..f9079446866479 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -1,4 +1,4 @@
-"Test , coverage 17%."
+"Test, coverage 22%."
 
 from idlelib import iomenu, util
 import unittest
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 582d742108cd61..93ec728d0abd86 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,4 +1,4 @@
-"Test constants and functions found in idlelib.util"
+"Test constants and functions found in idlelib.util, coverage 100%"
 
 import unittest
 from unittest import mock

From 4bba476b5107819b47499d61aed0e842dcdc09c0 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Sat, 16 Oct 2021 17:20:24 +0100
Subject: [PATCH 08/28] Add __main__ block for util.py, tweak added test for
 iomenu.py, tweak docstrings to keep line length within 72 chars

---
 Lib/idlelib/browser.py               | 6 +++---
 Lib/idlelib/idle_test/test_iomenu.py | 6 +++---
 Lib/idlelib/util.py                  | 7 ++++++-
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/Lib/idlelib/browser.py b/Lib/idlelib/browser.py
index 1168c49e240c9c..35736d0b9fd1ce 100644
--- a/Lib/idlelib/browser.py
+++ b/Lib/idlelib/browser.py
@@ -77,9 +77,9 @@ def __init__(self, master, path, *, _htest=False, _utest=False):
 
         Instance variables:
             name: Module name.
-            file: Full path and module with a valid Python extension. Used in
-                creating ModuleBrowserTreeItem as the rootnode for
-                the tree and subsequently in the children.
+            file: Full path and module with a valid Python extension.
+                Used in creating ModuleBrowserTreeItem as the rootnode
+                for the tree and subsequently in the children.
         """
         self.master = master
         self.path = path
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index f9079446866479..602d3c42799057 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -47,7 +47,7 @@ def test_fixnewlines_end(self):
 
 def _extension_is_in_IOBinding_dot_filetypes(extension):
     return any(
-        extension in filetype_tuple[1]
+        f'*{extension}' in filetype_tuple[1]
         for filetype_tuple in iomenu.IOBinding.filetypes
     )
 
@@ -58,10 +58,10 @@ def test_python_source_files(self):
             self.assertTrue(_extension_is_in_IOBinding_dot_filetypes(extension))
 
     def test_text_files(self):
-        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('*.txt'))
+        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('.txt'))
 
     def test_all_files(self):
-        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('*'))
+        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes(''))
 
 
 if __name__ == '__main__':
diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index 6ac0512c40d615..a003ffeacf5ef4 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -19,7 +19,7 @@
 
 
 def is_python_extension(extension, valid_extensions=PYTHON_EXTENSIONS):
-    """Identify whether a given string is a valid Python file extension."""
+    "Identify whether a given string is a valid Python file extension."
     return extension in valid_extensions
 
 
@@ -33,3 +33,8 @@ def is_python_source(filepath, firstline=None):
         and firstline.startswith('#!')
         and 'python' in firstline
     )
+
+
+if __name__ == '__main__':
+    from unittest import main
+    main('idlelib.idle_test.test_util', verbosity=2)

From be0043e56f02984e5a9d040bef3f4ab04a2ba771 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 18 Oct 2021 10:56:49 +0100
Subject: [PATCH 09/28] Tweak test_util.py

---
 Lib/idlelib/idle_test/test_util.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 93ec728d0abd86..ee56b9455762c5 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -39,8 +39,11 @@ def test_directory_filepath(self):
                 util.is_python_source(filepath='asdfoijf9245-98-$%^&*.json')
             )
 
-    def test_python_extension(self):
-        with mock.patch('idlelib.util.is_python_extension', return_value=True):
+    def test_filepath_with_python_extension(self):
+        with (
+            mock.patch('os.path.isdir', return_value=False),
+            mock.patch('idlelib.util.is_python_extension', return_value=True)
+        ):
             self.assertTrue(
                 util.is_python_source(filepath='asdfe798723%^&*^%£(.docx')
             )

From 5dc03fa2206329d95f315948114dfa132b25bde6 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Sun, 16 Jan 2022 09:19:13 +0000
Subject: [PATCH 10/28] Update Lib/idlelib/util.py

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
---
 Lib/idlelib/util.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index a003ffeacf5ef4..f13c2e3788548e 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -15,7 +15,7 @@
 from os import path
 
 # .pyw is for Windows; .pyi is for stub files.
-PYTHON_EXTENSIONS = frozenset({'.py', '.pyw', '.pyi'})
+PYTHON_EXTENSIONS = frozenset(('.py', '.pyw', '.pyi'))
 
 
 def is_python_extension(extension, valid_extensions=PYTHON_EXTENSIONS):

From 4b2c36cba3225bb843ed57884a29d6215ff66a50 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Sun, 16 Jan 2022 14:09:10 +0000
Subject: [PATCH 11/28] Add example `.pyi` file

---
 Lib/idlelib/idle_test/example.pyi | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Lib/idlelib/idle_test/example.pyi

diff --git a/Lib/idlelib/idle_test/example.pyi b/Lib/idlelib/idle_test/example.pyi
new file mode 100644
index 00000000000000..a9811a78d10a6e
--- /dev/null
+++ b/Lib/idlelib/idle_test/example.pyi
@@ -0,0 +1,2 @@
+class Example:
+    def method(self, argument1: str, argument2: list[int]) -> None: ...

From e9dfeb131f659297df4f453e7f61a57961b7b67b Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 18:32:06 +0000
Subject: [PATCH 12/28] Revert changes to coverage statistics

---
 Lib/idlelib/idle_test/test_browser.py | 2 +-
 Lib/idlelib/idle_test/test_editor.py  | 2 +-
 Lib/idlelib/idle_test/test_iomenu.py  | 2 +-
 Lib/idlelib/idle_test/test_util.py    | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_browser.py b/Lib/idlelib/idle_test/test_browser.py
index cd99a763e0a91b..03a50f22ca1e82 100644
--- a/Lib/idlelib/idle_test/test_browser.py
+++ b/Lib/idlelib/idle_test/test_browser.py
@@ -1,4 +1,4 @@
-"Test browser, coverage 81%."
+"Test browser, coverage 90%."
 
 from idlelib import browser
 from test.support import requires
diff --git a/Lib/idlelib/idle_test/test_editor.py b/Lib/idlelib/idle_test/test_editor.py
index 20a3bd04ee7e75..8665d680c0118f 100644
--- a/Lib/idlelib/idle_test/test_editor.py
+++ b/Lib/idlelib/idle_test/test_editor.py
@@ -1,4 +1,4 @@
-"Test editor, coverage 54%."
+"Test editor, coverage 35%."
 
 from idlelib import editor
 import unittest
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 602d3c42799057..ae0c5d0c625d7b 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -1,4 +1,4 @@
-"Test, coverage 22%."
+"Test , coverage 17%."
 
 from idlelib import iomenu, util
 import unittest
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index ee56b9455762c5..076edc2439c9ee 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,4 +1,4 @@
-"Test constants and functions found in idlelib.util, coverage 100%"
+"Test constants and functions found in idlelib.util"
 
 import unittest
 from unittest import mock

From a197c93d82dab0457edb8e5465a16a8e51404285 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 18:35:44 +0000
Subject: [PATCH 13/28] Rename `example.pyi` to `example_stub.pyi`

---
 Lib/idlelib/idle_test/{example.pyi => example_stub.pyi} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename Lib/idlelib/idle_test/{example.pyi => example_stub.pyi} (100%)

diff --git a/Lib/idlelib/idle_test/example.pyi b/Lib/idlelib/idle_test/example_stub.pyi
similarity index 100%
rename from Lib/idlelib/idle_test/example.pyi
rename to Lib/idlelib/idle_test/example_stub.pyi

From eb754bdfadb0d746dd8186114e7f41c1e73dee5b Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 18:38:43 +0000
Subject: [PATCH 14/28] Have stub files combined with other Python files in
 `iomenu.py`

---
 Lib/idlelib/iomenu.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 57a41182349085..14c4e97cfcb379 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -348,8 +348,7 @@ def print_window(self, event):
     savedialog = None
 
     filetypes = (
-        ("Python files", "*.py *.pyw", "TEXT"),
-        ("Python stub files", "*.pyi", "TEXT"),
+        ("Python files", "*.py *pyi *.pyw", "TEXT"),
         ("Text files", "*.txt", "TEXT"),
         ("All files", "*"),
         )

From c6bd52479fe996d7d74cfbffb16d73a6253cca4d Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 23:22:48 +0000
Subject: [PATCH 15/28] Fix broken test, improve other tests

---
 Lib/idlelib/idle_test/test_iomenu.py |  5 +-
 Lib/idlelib/idle_test/test_util.py   | 73 +++++++++++++---------------
 Lib/idlelib/iomenu.py                |  2 +-
 3 files changed, 39 insertions(+), 41 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index ae0c5d0c625d7b..5ac1cc44d37ea3 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -55,7 +55,10 @@ def _extension_is_in_IOBinding_dot_filetypes(extension):
 class FiletypesTest(unittest.TestCase):
     def test_python_source_files(self):
         for extension in util.PYTHON_EXTENSIONS:
-            self.assertTrue(_extension_is_in_IOBinding_dot_filetypes(extension))
+            with self.subTest(extension=extension):
+                self.assertTrue(
+                    _extension_is_in_IOBinding_dot_filetypes(extension)
+                )
 
     def test_text_files(self):
         self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('.txt'))
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 076edc2439c9ee..ed48314e1d9004 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -6,27 +6,22 @@
 
 
 class ExtensionTest(unittest.TestCase):
-    def test_pyi(self):
-        self.assertIn('.pyi', util.PYTHON_EXTENSIONS)
-
-    def test_py(self):
-        self.assertIn('.py', util.PYTHON_EXTENSIONS)
-
-    def test_pyw(self):
-        self.assertIn('.pyw', util.PYTHON_EXTENSIONS)
+    def test_extensions(self):
+        for extension in {'.pyi', '.py', '.pyw'}:
+            with self.subTest(extension=extension):
+                self.assertIn(extension, util.PYTHON_EXTENSIONS)
 
 
 class IsPythonExtensionTest(unittest.TestCase):    
     def test_positives(self):
         for extension in util.PYTHON_EXTENSIONS:
-            self.assertTrue(util.is_python_extension(extension))
+            with self.subTest(extension=extension):
+                self.assertTrue(util.is_python_extension(extension))
 
     def test_negatives(self):
-        self.assertFalse(util.is_python_extension('.pyc'))
-        self.assertFalse(util.is_python_extension('.p'))
-        self.assertFalse(util.is_python_extension('.pyy'))
-        self.assertFalse(util.is_python_extension('..py'))
-        self.assertFalse(util.is_python_extension('.ppy'))
+        for bad_extension in {'.pyc', '.p', '.pyy', '..py', '.ppy'}:
+            with self.subTest(bad_extension=bad_extension):
+                self.assertFalse(util.is_python_extension(bad_extension))
 
 
 class IsPythonSourceTest(unittest.TestCase):
@@ -57,41 +52,41 @@ def test_bad_filepath_no_firstline(self):
                 util.is_python_source(filepath='%^*iupoukjcj&)9675889')
             )
 
-    def test_bad_filepath_good_firstline(self):        
+    def test_bad_filepath_good_firstline(self):
+        test_cases = (
+            ('ad^%^&*yoi724)', '#!python'),
+            ('7890J:IUJjhu435465$£^%£', '#!     python'),
+            ('$%^&554657jhasfnmnbnnnm', '#!asdfkpoijeqrjiumnbjypythonasdfjlh')
+        )
+
         with (
             mock.patch('os.path.isdir', return_value=False),
             mock.patch('idlelib.util.is_python_extension', return_value=False)
         ):
-            self.assertTrue(util.is_python_source(
-                filepath='ad^%^&*yoi724)',
-                firstline='#!python'
-            ))
-            self.assertTrue(util.is_python_source(
-                filepath='7890J:IUJjhu435465$£^%£',
-                firstline='#!     python'
-            ))
-            self.assertTrue(util.is_python_source(
-                filepath='$%^&554657jhasfnmnbnnnm',
-                firstline='#!asdfkpoijeqrjiumnbjypythonasdfjlh'
-            ))
+            for filepath, firstline in test_cases:
+                with self.subTest(filepath=filepath, firstline=firstline):
+                    self.assertTrue(util.is_python_source(
+                        filepath=filepath,
+                        firstline=firstline
+                    ))
 
     def test_bad_filepath_bad_firstline(self):
+        test_cases = (
+            ('tyyuiuoiu', '#python!'),
+            ('796923568%^&**$', '!#python'),
+            ('67879iy987kjl87', 'python#!')
+        )
+
         with (
             mock.patch('os.path.isdir', return_value=False),
             mock.patch('idlelib.util.is_python_extension', return_value=False)
         ):
-            self.assertFalse(util.is_python_source(
-                filepath='tyyuiuoiu',
-                firstline='#python!'
-            ))
-            self.assertFalse(util.is_python_source(
-                filepath='796923568%^&**$',
-                firstline='!#python'
-            ))
-            self.assertFalse(util.is_python_source(
-                filepath='67879iy987kjl87',
-                firstline='python#!'
-            ))
+            for filepath, firstline in test_cases:
+                with self.subTest(filepath=filepath, firstline=firstline):
+                    self.assertFalse(util.is_python_source(
+                        filepath=filepath,
+                        firstline=firstline
+                    ))
 
 
 if __name__ == '__main__':
diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 14c4e97cfcb379..70de9aa08b470d 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -348,7 +348,7 @@ def print_window(self, event):
     savedialog = None
 
     filetypes = (
-        ("Python files", "*.py *pyi *.pyw", "TEXT"),
+        ("Python files", "*.py *.pyi *.pyw", "TEXT"),
         ("Text files", "*.txt", "TEXT"),
         ("All files", "*"),
         )

From 5a74935ba1ab610953a31bcb364f5eef70ca04fd Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 23:26:35 +0000
Subject: [PATCH 16/28] Add `example_noext` file

---
 Lib/idlelib/idle_test/example_noext | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 Lib/idlelib/idle_test/example_noext

diff --git a/Lib/idlelib/idle_test/example_noext b/Lib/idlelib/idle_test/example_noext
new file mode 100644
index 00000000000000..7d2510e30bc0ae
--- /dev/null
+++ b/Lib/idlelib/idle_test/example_noext
@@ -0,0 +1,4 @@
+#!usr/bin/env python
+
+def example_function(some_argument):
+    pass

From 84b925186e98f10ad9e37e14347a18d211c0b4ba Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Mon, 24 Jan 2022 23:32:41 +0000
Subject: [PATCH 17/28] Add entry to 'What's new in 3.11'

---
 Doc/whatsnew/3.11.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index 4328ee6a5030cd..dd4daa52933aee 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -226,6 +226,13 @@ fractions
   (Contributed by Mark Dickinson in :issue:`44547`.)
 
 
+IDLE and idlelib
+----------------
+
+* IDLE now applies syntax highlighting to `.pyi` files. (Contributed by Alex
+  Waygood in :issue:`45447`.)
+
+
 inspect
 -------
 * Add :func:`inspect.getmembers_static`: return all members without

From 58fef8e4d8c0bba3a7e54e486435ae2d643b7639 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Thu, 10 Feb 2022 23:56:51 -0500
Subject: [PATCH 18/28] Revert changes in browser.py

---
 Lib/idlelib/browser.py | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/Lib/idlelib/browser.py b/Lib/idlelib/browser.py
index 35736d0b9fd1ce..3c3a53a6599a79 100644
--- a/Lib/idlelib/browser.py
+++ b/Lib/idlelib/browser.py
@@ -13,7 +13,6 @@
 import pyclbr
 import sys
 
-from idlelib.util import is_python_source, is_python_extension
 from idlelib.config import idleConf
 from idlelib import pyshell
 from idlelib.tree import TreeNode, TreeItem, ScrolledCanvas
@@ -77,9 +76,9 @@ def __init__(self, master, path, *, _htest=False, _utest=False):
 
         Instance variables:
             name: Module name.
-            file: Full path and module with a valid Python extension.
-                Used in creating ModuleBrowserTreeItem as the rootnode
-                for the tree and subsequently in the children.
+            file: Full path and module with .py extension.  Used in
+                creating ModuleBrowserTreeItem as the rootnode for
+                the tree and subsequently in the children.
         """
         self.master = master
         self.path = path
@@ -162,19 +161,21 @@ def GetSubList(self):
 
     def OnDoubleClick(self):
         "Open a module in an editor window when double clicked."
-        if self.IsExpandable() and os.path.exists(self.file):
-            file_open(self.file)
+        if os.path.normcase(self.file[-3:]) != ".py":
+            return
+        if not os.path.exists(self.file):
+            return
+        file_open(self.file)
 
     def IsExpandable(self):
-        "Identify whether `self.file` is a valid Python file."
-        # see idlelib.util for currently supported Python extensions.
-        return is_python_source(self.file)
+        "Return True if Python (.py) file."
+        return os.path.normcase(self.file[-3:]) == ".py"
 
     def listchildren(self):
         "Return sequenced classes and functions in the module."
         dir, base = os.path.split(self.file)
         name, ext = os.path.splitext(base)
-        if not is_python_extension(os.path.normcase(ext)):
+        if os.path.normcase(ext) != ".py":
             return []
         try:
             tree = pyclbr.readmodule_ex(name, [dir] + sys.path)

From 00a51b279ffacffabc733659d8f48984b038f3e5 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Thu, 10 Feb 2022 23:57:41 -0500
Subject: [PATCH 19/28] Revert changes to editor.EditorWindow.ispythonsource.

---
 Lib/idlelib/editor.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index b82277b0209f55..e660830b94e561 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -755,10 +755,13 @@ def gotoline(self, lineno):
             self.center()
 
     def ispythonsource(self, filename):
-        return idlelib.util.is_python_source(
-            filepath=filename,
-            firstline=self.text.get('1.0', '1.0 lineend')
-        )
+        if not filename or os.path.isdir(filename):
+            return True
+        base, ext = os.path.splitext(os.path.basename(filename))
+        if os.path.normcase(ext) in (".py", ".pyw"):
+            return True
+        line = self.text.get('1.0', '1.0 lineend')
+        return line.startswith('#!') and 'python' in line
 
     def close_hook(self):
         if self.flist:

From a5890997d835a9840ecbada3bb896dd773db4ccd Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 00:04:18 -0500
Subject: [PATCH 20/28] Revise util, removing new functions.

---
 Lib/idlelib/util.py | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index f13c2e3788548e..9483d5a7c118a0 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -15,25 +15,7 @@
 from os import path
 
 # .pyw is for Windows; .pyi is for stub files.
-PYTHON_EXTENSIONS = frozenset(('.py', '.pyw', '.pyi'))
-
-
-def is_python_extension(extension, valid_extensions=PYTHON_EXTENSIONS):
-    "Identify whether a given string is a valid Python file extension."
-    return extension in valid_extensions
-
-
-def is_python_source(filepath, firstline=None):
-    """Identify whether a given path is valid as a Python module."""
-    if not filepath or path.isdir(filepath):
-        return True
-    base, ext = path.splitext(path.basename(filepath))
-    return is_python_extension(path.normcase(ext)) or (
-        firstline is not None
-        and firstline.startswith('#!')
-        and 'python' in firstline
-    )
-
+py_extensions = frozenset(('.py', '.pyw', '.pyi'))
 
 if __name__ == '__main__':
     from unittest import main

From 647ae1adce11853c3bfa0fda2c342e57b1601038 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 00:13:30 -0500
Subject: [PATCH 21/28] Revise test_util, deleting most tests.

---
 Lib/idlelib/idle_test/test_util.py | 86 ++----------------------------
 1 file changed, 4 insertions(+), 82 deletions(-)

diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index ed48314e1d9004..29e9b9a588cffe 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,92 +1,14 @@
-"Test constants and functions found in idlelib.util"
+"""Test util, coverage 100%"""
 
 import unittest
-from unittest import mock
+#from unittest import mock
 from idlelib import util
 
 
-class ExtensionTest(unittest.TestCase):
+class UtilTest(unittest.TestCase):
     def test_extensions(self):
         for extension in {'.pyi', '.py', '.pyw'}:
-            with self.subTest(extension=extension):
-                self.assertIn(extension, util.PYTHON_EXTENSIONS)
-
-
-class IsPythonExtensionTest(unittest.TestCase):    
-    def test_positives(self):
-        for extension in util.PYTHON_EXTENSIONS:
-            with self.subTest(extension=extension):
-                self.assertTrue(util.is_python_extension(extension))
-
-    def test_negatives(self):
-        for bad_extension in {'.pyc', '.p', '.pyy', '..py', '.ppy'}:
-            with self.subTest(bad_extension=bad_extension):
-                self.assertFalse(util.is_python_extension(bad_extension))
-
-
-class IsPythonSourceTest(unittest.TestCase):
-    def test_empty_string_filepath(self):
-        self.assertTrue(util.is_python_source(''))
-
-    def test_directory_filepath(self):
-        with mock.patch('os.path.isdir', return_value=True):
-            self.assertTrue(
-                util.is_python_source(filepath='asdfoijf9245-98-$%^&*.json')
-            )
-
-    def test_filepath_with_python_extension(self):
-        with (
-            mock.patch('os.path.isdir', return_value=False),
-            mock.patch('idlelib.util.is_python_extension', return_value=True)
-        ):
-            self.assertTrue(
-                util.is_python_source(filepath='asdfe798723%^&*^%£(.docx')
-            )
-
-    def test_bad_filepath_no_firstline(self):
-        with (
-            mock.patch('os.path.isdir', return_value=False),
-            mock.patch('idlelib.util.is_python_extension', return_value=False)
-        ):
-            self.assertFalse(
-                util.is_python_source(filepath='%^*iupoukjcj&)9675889')
-            )
-
-    def test_bad_filepath_good_firstline(self):
-        test_cases = (
-            ('ad^%^&*yoi724)', '#!python'),
-            ('7890J:IUJjhu435465$£^%£', '#!     python'),
-            ('$%^&554657jhasfnmnbnnnm', '#!asdfkpoijeqrjiumnbjypythonasdfjlh')
-        )
-
-        with (
-            mock.patch('os.path.isdir', return_value=False),
-            mock.patch('idlelib.util.is_python_extension', return_value=False)
-        ):
-            for filepath, firstline in test_cases:
-                with self.subTest(filepath=filepath, firstline=firstline):
-                    self.assertTrue(util.is_python_source(
-                        filepath=filepath,
-                        firstline=firstline
-                    ))
-
-    def test_bad_filepath_bad_firstline(self):
-        test_cases = (
-            ('tyyuiuoiu', '#python!'),
-            ('796923568%^&**$', '!#python'),
-            ('67879iy987kjl87', 'python#!')
-        )
-
-        with (
-            mock.patch('os.path.isdir', return_value=False),
-            mock.patch('idlelib.util.is_python_extension', return_value=False)
-        ):
-            for filepath, firstline in test_cases:
-                with self.subTest(filepath=filepath, firstline=firstline):
-                    self.assertFalse(util.is_python_source(
-                        filepath=filepath,
-                        firstline=firstline
-                    ))
+            self.assertIn(extension, util.py_extensions)
 
 
 if __name__ == '__main__':

From a090db71e93d714a1c7f4c77ea1c0fcd327088cc Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 01:08:27 -0500
Subject: [PATCH 22/28] Use tuple instead of frozen set.

This enables computing text for open/save dialogs.
.py must be first to make it default on non-macOS.
---
 Lib/idlelib/editor.py                | 4 ++--
 Lib/idlelib/idle_test/test_iomenu.py | 2 +-
 Lib/idlelib/iomenu.py                | 5 ++++-
 Lib/idlelib/util.py                  | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index e660830b94e561..6c52efd655e121 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -15,7 +15,6 @@
 from tkinter import simpledialog
 from tkinter import messagebox
 
-import idlelib.util
 from idlelib.config import idleConf
 from idlelib import configdialog
 from idlelib import grep
@@ -28,6 +27,7 @@
 from idlelib import replace
 from idlelib import search
 from idlelib.tree import wheel_event
+from idlelib.util import py_extensions
 from idlelib import window
 
 # The default tab setting for a Text widget, in average-width characters.
@@ -758,7 +758,7 @@ def ispythonsource(self, filename):
         if not filename or os.path.isdir(filename):
             return True
         base, ext = os.path.splitext(os.path.basename(filename))
-        if os.path.normcase(ext) in (".py", ".pyw"):
+        if os.path.normcase(ext) in py_extensions:
             return True
         line = self.text.get('1.0', '1.0 lineend')
         return line.startswith('#!') and 'python' in line
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 5ac1cc44d37ea3..849863d9a90acb 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -54,7 +54,7 @@ def _extension_is_in_IOBinding_dot_filetypes(extension):
 
 class FiletypesTest(unittest.TestCase):
     def test_python_source_files(self):
-        for extension in util.PYTHON_EXTENSIONS:
+        for extension in util.py_extensions:
             with self.subTest(extension=extension):
                 self.assertTrue(
                     _extension_is_in_IOBinding_dot_filetypes(extension)
diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 70de9aa08b470d..ad3109df84096a 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -11,6 +11,9 @@
 
 import idlelib
 from idlelib.config import idleConf
+from idlelib.util import py_extensions
+
+py_extensions = ' '.join("*"+ext for ext in py_extensions)
 
 encoding = 'utf-8'
 if sys.platform == 'win32':
@@ -348,7 +351,7 @@ def print_window(self, event):
     savedialog = None
 
     filetypes = (
-        ("Python files", "*.py *.pyi *.pyw", "TEXT"),
+        ("Python files", py_extensions, "TEXT"),
         ("Text files", "*.txt", "TEXT"),
         ("All files", "*"),
         )
diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index 9483d5a7c118a0..5480219786bca6 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -15,7 +15,7 @@
 from os import path
 
 # .pyw is for Windows; .pyi is for stub files.
-py_extensions = frozenset(('.py', '.pyw', '.pyi'))
+py_extensions = ('.py', '.pyw', '.pyi')  # Order needed for open/save dialogs.
 
 if __name__ == '__main__':
     from unittest import main

From fc9e587d41f094592d9f31509f7371e6b92e755c Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 01:16:11 -0500
Subject: [PATCH 23/28] Update 2021-10-14-16-55-03.bpo-45447.FhiH5P.rst

---
 Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
index 35ccd29487ce13..bad30b0f6f31a1 100644
--- a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
+++ b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
@@ -1 +1,2 @@
-IDLE now applies syntax highlighting to `.pyi` files. Patch by Alex Waygood.
+IDLE now applies syntax highlighting to `.pyi` files. Patch by Alex Waygood
+and Terry Jan Reedy.

From 70f06f1a7ffe4c5e23fd0ab2c0863af8d61eb381 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 01:16:32 -0500
Subject: [PATCH 24/28] Create 3.11.rst

---
 Doc/whatsnew/3.11.rst | 139 ++++++++++++++----------------------------
 1 file changed, 46 insertions(+), 93 deletions(-)

diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index 19ee49a4e33cc4..061013d48cc85b 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -67,8 +67,6 @@ Summary -- Release highlights
 
 PEP-654: Exception Groups and ``except*``.
 (Contributed by Irit Katriel in :issue:`45292`.)
-PEP-673: ``Self`` Type.
-(Contributed by James Hilton-Balfe and Pradeep Kumar in :issue:`30924`.)
 
 New Features
 ============
@@ -232,7 +230,7 @@ IDLE and idlelib
 ----------------
 
 * IDLE now applies syntax highlighting to `.pyi` files. (Contributed by Alex
-  Waygood in :issue:`45447`.)
+  Waygood and Terry Jan Reedy in :issue:`45447`.)
 
 
 inspect
@@ -409,8 +407,7 @@ CPython bytecode changes
 
 * Replaced the three call instructions: :opcode:`CALL_FUNCTION`,
   :opcode:`CALL_FUNCTION_KW` and :opcode:`CALL_METHOD` with
-  :opcode:`PRECALL_FUNCTION`, :opcode:`PRECALL_METHOD`, :opcode:`CALL`,
-  and :opcode:`KW_NAMES`.
+  :opcode:`CALL_NO_KW`, :opcode:`CALL_KW` and :opcode:`PRECALL_METHOD`.
   This decouples the argument shifting for methods from the handling of
   keyword arguments and allows better specialization of calls.
 
@@ -421,9 +418,8 @@ CPython bytecode changes
   indicate failure with :const:`None` (where a tuple of extracted values would
   otherwise be).
 
-* Replace several stack manipulation instructions (``DUP_TOP``, ``DUP_TOP_TWO``,
-  ``ROT_TWO``, ``ROT_THREE``, ``ROT_FOUR``, and ``ROT_N``) with new
-  :opcode:`COPY` and :opcode:`SWAP` instructions.
+* Added :opcode:`COPY`, which pushes the *i*-th item to the top of the stack.
+  The item is not removed from its original location.
 
 * Add :opcode:`POP_JUMP_IF_NOT_NONE` and :opcode:`POP_JUMP_IF_NONE` opcodes to
   speed up conditional jumps.
@@ -467,22 +463,6 @@ Deprecated
   as deprecated, its docstring is now corrected).
   (Contributed by Hugo van Kemenade in :issue:`45837`.)
 
-* The delegation of :func:`int` to :meth:`__trunc__` is now deprecated. Calling
-  ``int(a)`` when ``type(a)`` implements :meth:`__trunc__` but not
-  :meth:`__int__` or :meth:`__index__` now raises a :exc:`DeprecationWarning`.
-  (Contributed by Zackery Spytz in :issue:`44977`.)
-
-* The following have been deprecated in :mod:`configparser` since Python 3.2.
-  Their deprecation warnings have now been updated to note they will removed in
-  Python 3.12:
-
-  * the :class:`configparser.SafeConfigParser` class
-  * the :attr:`configparser.ParsingError.filename` property
-  * the :meth:`configparser.ParsingError.readfp` method
-
-  (Contributed by Hugo van Kemenade in :issue:`45173`.)
-
-
 Removed
 =======
 
@@ -515,6 +495,28 @@ Removed
   and :class:`fileinput.FileInput`, deprecated since Python 3.9.
   (Contributed by Hugo van Kemenade in :issue:`45132`.)
 
+* Removed many old deprecated :mod:`unittest` features:
+
+  - :class:`~unittest.TestCase` method aliases ``failUnlessEqual``,
+    ``failIfEqual``, ``failUnless``, ``failIf``, ``failUnlessRaises``,
+    ``failUnlessAlmostEqual``, ``failIfAlmostEqual`` (deprecated in Python 3.1),
+    ``assertEquals``, ``assertNotEquals``, ``assert_``, ``assertAlmostEquals``,
+    ``assertNotAlmostEquals``, ``assertRegexpMatches``, ``assertRaisesRegexp``
+    (deprecated in Python 3.2), and ``assertNotRegexpMatches`` (deprecated in
+    Python 3.5).
+
+  - Undocumented and broken :class:`~unittest.TestCase` method
+    ``assertDictContainsSubset`` (deprecated in Python 3.2).
+
+  - Undocumented :meth:`<unittest.TestLoader.loadTestsFromModule>
+    TestLoader.loadTestsFromModule` parameter *use_load_tests* (deprecated
+    and ignored since Python 3.2).
+
+  - An alias of the :class:`~unittest.TextTestResult` class:
+    ``_TextTestResult`` (deprecated in Python 3.2).
+
+  (Contributed by Serhiy Storchaka in :issue:`45162`.)
+
 * The following deprecated functions and methods are removed in the :mod:`gettext`
   module: :func:`~gettext.lgettext`, :func:`~gettext.ldgettext`,
   :func:`~gettext.lngettext` and :func:`~gettext.ldngettext`.
@@ -527,6 +529,13 @@ Removed
   the ``l*gettext()`` functions.
   (Contributed by Dong-hee Na and Serhiy Storchaka in :issue:`44235`.)
 
+* Removed from the :mod:`configparser` module:
+  the :class:`SafeConfigParser` class,
+  the :attr:`filename` property of the :class:`ParsingError` class,
+  the :meth:`readfp` method of the :class:`ConfigParser` class,
+  deprecated since Python 3.2.
+  (Contributed by Hugo van Kemenade in :issue:`45173`.)
+
 * The :func:`@asyncio.coroutine <asyncio.coroutine>` :term:`decorator` enabling
   legacy generator-based coroutines to be compatible with async/await code.
   The function has been deprecated since Python 3.8 and the removal was
@@ -560,9 +569,6 @@ Removed
   Python 3.4 but has been broken since Python 3.7.
   (Contributed by Inada Naoki in :issue:`23882`.)
 
-* Remove ``__class_getitem__`` method from :class:`pathlib.PurePath`,
-  because it was not used and added by mistake in previous versions.
-  (Contributed by Nikita Sobolev in :issue:`46483`.)
 
 Porting to Python 3.11
 ======================
@@ -598,12 +604,6 @@ Changes in the Python API
   of sorting simply isn't well-defined in the absence of a total ordering
   on list elements.
 
-* :mod:`calendar`: The :class:`calendar.LocaleTextCalendar` and
-  :class:`calendar.LocaleHTMLCalendar` classes now use
-  :func:`locale.getlocale`, instead of using :func:`locale.getdefaultlocale`,
-  if no locale is specified.
-  (Contributed by Victor Stinner in :issue:`46659`.)
-
 
 Build Changes
 =============
@@ -619,12 +619,6 @@ Build Changes
   ``isinf()``, ``isnan()``, ``round()``.
   (Contributed by Victor Stinner in :issue:`45440`.)
 
-* Building Python now requires a C99 ``<math.h>`` header file providing
-  a ``NAN`` constant, or the ``__builtin_nan()`` built-in function. If a
-  platform does not support Not-a-Number (NaN), the ``Py_NO_NAN`` macro can be
-  defined in the ``pyconfig.h`` file.
-  (Contributed by Victor Stinner in :issue:`46640`.)
-
 * Freelists for object structs can now be disabled. A new :program:`configure`
   option :option:`!--without-freelists` can be used to disable all freelists
   except empty tuple singleton.
@@ -671,11 +665,6 @@ C API Changes
   fields of the result from the exception instance (the ``value`` field).
   (Contributed by Irit Katriel in :issue:`45711`.)
 
-* :c:struct:`_frozen` has a new ``is_package`` field to indicate whether
-  or not the frozen module is a package.  Previously, a negative value
-  in the ``size`` field was the indicator.  Now only non-negative values
-  be used for ``size``.
-  (Contributed by Kumar Aditya in :issue:`46608`.)
 
 New Features
 ------------
@@ -695,26 +684,6 @@ New Features
   :c:macro:`PY_VERSION_HEX`.
   (Contributed by  Gabriele N. Tornetta in :issue:`43931`.)
 
-* :c:type:`Py_buffer` and APIs are now part of the limited API and the stable
-  ABI:
-
-  * :c:func:`PyObject_CheckBuffer`
-  * :c:func:`PyObject_GetBuffer`
-  * :c:func:`PyBuffer_GetPointer`
-  * :c:func:`PyBuffer_SizeFromFormat`
-  * :c:func:`PyBuffer_ToContiguous`
-  * :c:func:`PyBuffer_FromContiguous`
-  * :c:func:`PyBuffer_CopyData`
-  * :c:func:`PyBuffer_IsContiguous`
-  * :c:func:`PyBuffer_FillContiguousStrides`
-  * :c:func:`PyBuffer_FillInfo`
-  * :c:func:`PyBuffer_Release`
-  * :c:func:`PyMemoryView_FromBuffer`
-  * :c:member:`~PyBufferProcs.bf_getbuffer` and
-    :c:member:`~PyBufferProcs.bf_releasebuffer` type slots
-
-  (Contributed by Christian Heimes in :issue:`45459`.)
-
 
 Porting to Python 3.11
 ----------------------
@@ -817,38 +786,27 @@ Porting to Python 3.11
   which are not available in the limited C API.
   (Contributed by Victor Stinner in :issue:`46007`.)
 
-* Changes of the private :c:type:`PyFrameObject` structure members.
-
-  While the documentation notes that the fields of ``PyFrameObject`` are
-  subject to change at any time, they have been stable for a long time
-  and were used in several popular extensions.
-  In Python 3.11, the frame struct was reorganized to allow performance
-  optimizations. Rather than reading the fields directly, extensions should
-  use functions:
+* Changes of the :c:type:`PyFrameObject` structure members:
 
   * ``f_code``: removed, use :c:func:`PyFrame_GetCode` instead.
     Warning: the function returns a :term:`strong reference`, need to call
     :c:func:`Py_DECREF`.
-  * ``f_back``: changed (see below), use :c:func:`PyFrame_GetBack`.
+  * ``f_back``: changed, use :c:func:`PyFrame_GetBack`.
   * ``f_builtins``: removed,
-    use ``PyObject_GetAttrString((PyObject*)frame, "f_builtins")``.
+    use ``PyObject_GetAttrString(frame, "f_builtins")``.
   * ``f_globals``: removed,
-    use ``PyObject_GetAttrString((PyObject*)frame, "f_globals")``.
+    use ``PyObject_GetAttrString(frame, "f_globals")``.
   * ``f_locals``: removed,
-    use ``PyObject_GetAttrString((PyObject*)frame, "f_locals")``.
+    use ``PyObject_GetAttrString(frame, "f_locals")``.
   * ``f_lasti``: removed,
-    use ``PyObject_GetAttrString((PyObject*)frame, "f_lasti")``.
-
-  The following fields were removed entirely, as they were details
-  of the old implementation:
-
-  * ``f_valuesstack``
-  * ``f_stackdepth``
-  * ``f_gen``
-  * ``f_iblock``
-  * ``f_state``
-  * ``f_blockstack``
-  * ``f_localsplus``
+    use ``PyObject_GetAttrString(frame, "f_lasti")``.
+  * ``f_valuesstack``: removed.
+  * ``f_stackdepth``: removed.
+  * ``f_gen``: removed.
+  * ``f_iblock``: removed.
+  * ``f_state``: removed.
+  * ``f_blockstack``: removed.
+  * ``f_localsplus``: removed.
 
   The Python frame object is now created lazily. A side effect is that the
   ``f_back`` member must not be accessed directly, since its value is now also
@@ -999,8 +957,3 @@ Removed
   worked since the :c:type:`PyWeakReference` structure is opaque in the
   limited C API.
   (Contributed by Victor Stinner in :issue:`35134`.)
-
-* Remove the ``PyHeapType_GET_MEMBERS()`` macro. It was exposed in the
-  public C API by mistake, it must only be used by Python internally.
-  Use the ``PyTypeObject.tp_members`` member instead.
-  (Contributed by Victor Stinner in :issue:`40170`.)

From d4d3906b2b80c8fff950594d53c1d994c54be900 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 01:18:14 -0500
Subject: [PATCH 25/28] Update 3.11.rst

---
 Doc/whatsnew/3.11.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index 061013d48cc85b..e0aeaf10a3bbba 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -68,6 +68,10 @@ Summary -- Release highlights
 PEP-654: Exception Groups and ``except*``.
 (Contributed by Irit Katriel in :issue:`45292`.)
 
+PEP-673: ``Self`` Type.
+(Contributed by James Hilton-Balfe and Pradeep Kumar in :issue:`30924`.)
+
+
 New Features
 ============
 

From aafd8e29e2d06c645a004f1c0c0637f163114354 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Fri, 11 Feb 2022 01:27:43 -0500
Subject: [PATCH 26/28] Revert unwanted changed to what's new

---
 Doc/whatsnew/3.11.rst | 138 +++++++++++++++++++++++++++---------------
 1 file changed, 90 insertions(+), 48 deletions(-)

diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index e0aeaf10a3bbba..3d210ce6a9a6b2 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -67,11 +67,9 @@ Summary -- Release highlights
 
 PEP-654: Exception Groups and ``except*``.
 (Contributed by Irit Katriel in :issue:`45292`.)
-
 PEP-673: ``Self`` Type.
 (Contributed by James Hilton-Balfe and Pradeep Kumar in :issue:`30924`.)
 
-
 New Features
 ============
 
@@ -236,7 +234,6 @@ IDLE and idlelib
 * IDLE now applies syntax highlighting to `.pyi` files. (Contributed by Alex
   Waygood and Terry Jan Reedy in :issue:`45447`.)
 
-
 inspect
 -------
 * Add :func:`inspect.getmembers_static`: return all members without
@@ -411,7 +408,8 @@ CPython bytecode changes
 
 * Replaced the three call instructions: :opcode:`CALL_FUNCTION`,
   :opcode:`CALL_FUNCTION_KW` and :opcode:`CALL_METHOD` with
-  :opcode:`CALL_NO_KW`, :opcode:`CALL_KW` and :opcode:`PRECALL_METHOD`.
+  :opcode:`PRECALL_FUNCTION`, :opcode:`PRECALL_METHOD`, :opcode:`CALL`,
+  and :opcode:`KW_NAMES`.
   This decouples the argument shifting for methods from the handling of
   keyword arguments and allows better specialization of calls.
 
@@ -422,8 +420,9 @@ CPython bytecode changes
   indicate failure with :const:`None` (where a tuple of extracted values would
   otherwise be).
 
-* Added :opcode:`COPY`, which pushes the *i*-th item to the top of the stack.
-  The item is not removed from its original location.
+* Replace several stack manipulation instructions (``DUP_TOP``, ``DUP_TOP_TWO``,
+  ``ROT_TWO``, ``ROT_THREE``, ``ROT_FOUR``, and ``ROT_N``) with new
+  :opcode:`COPY` and :opcode:`SWAP` instructions.
 
 * Add :opcode:`POP_JUMP_IF_NOT_NONE` and :opcode:`POP_JUMP_IF_NONE` opcodes to
   speed up conditional jumps.
@@ -467,6 +466,22 @@ Deprecated
   as deprecated, its docstring is now corrected).
   (Contributed by Hugo van Kemenade in :issue:`45837`.)
 
+* The delegation of :func:`int` to :meth:`__trunc__` is now deprecated. Calling
+  ``int(a)`` when ``type(a)`` implements :meth:`__trunc__` but not
+  :meth:`__int__` or :meth:`__index__` now raises a :exc:`DeprecationWarning`.
+  (Contributed by Zackery Spytz in :issue:`44977`.)
+
+* The following have been deprecated in :mod:`configparser` since Python 3.2.
+  Their deprecation warnings have now been updated to note they will removed in
+  Python 3.12:
+
+  * the :class:`configparser.SafeConfigParser` class
+  * the :attr:`configparser.ParsingError.filename` property
+  * the :meth:`configparser.ParsingError.readfp` method
+
+  (Contributed by Hugo van Kemenade in :issue:`45173`.)
+
+
 Removed
 =======
 
@@ -499,28 +514,6 @@ Removed
   and :class:`fileinput.FileInput`, deprecated since Python 3.9.
   (Contributed by Hugo van Kemenade in :issue:`45132`.)
 
-* Removed many old deprecated :mod:`unittest` features:
-
-  - :class:`~unittest.TestCase` method aliases ``failUnlessEqual``,
-    ``failIfEqual``, ``failUnless``, ``failIf``, ``failUnlessRaises``,
-    ``failUnlessAlmostEqual``, ``failIfAlmostEqual`` (deprecated in Python 3.1),
-    ``assertEquals``, ``assertNotEquals``, ``assert_``, ``assertAlmostEquals``,
-    ``assertNotAlmostEquals``, ``assertRegexpMatches``, ``assertRaisesRegexp``
-    (deprecated in Python 3.2), and ``assertNotRegexpMatches`` (deprecated in
-    Python 3.5).
-
-  - Undocumented and broken :class:`~unittest.TestCase` method
-    ``assertDictContainsSubset`` (deprecated in Python 3.2).
-
-  - Undocumented :meth:`<unittest.TestLoader.loadTestsFromModule>
-    TestLoader.loadTestsFromModule` parameter *use_load_tests* (deprecated
-    and ignored since Python 3.2).
-
-  - An alias of the :class:`~unittest.TextTestResult` class:
-    ``_TextTestResult`` (deprecated in Python 3.2).
-
-  (Contributed by Serhiy Storchaka in :issue:`45162`.)
-
 * The following deprecated functions and methods are removed in the :mod:`gettext`
   module: :func:`~gettext.lgettext`, :func:`~gettext.ldgettext`,
   :func:`~gettext.lngettext` and :func:`~gettext.ldngettext`.
@@ -533,13 +526,6 @@ Removed
   the ``l*gettext()`` functions.
   (Contributed by Dong-hee Na and Serhiy Storchaka in :issue:`44235`.)
 
-* Removed from the :mod:`configparser` module:
-  the :class:`SafeConfigParser` class,
-  the :attr:`filename` property of the :class:`ParsingError` class,
-  the :meth:`readfp` method of the :class:`ConfigParser` class,
-  deprecated since Python 3.2.
-  (Contributed by Hugo van Kemenade in :issue:`45173`.)
-
 * The :func:`@asyncio.coroutine <asyncio.coroutine>` :term:`decorator` enabling
   legacy generator-based coroutines to be compatible with async/await code.
   The function has been deprecated since Python 3.8 and the removal was
@@ -573,6 +559,9 @@ Removed
   Python 3.4 but has been broken since Python 3.7.
   (Contributed by Inada Naoki in :issue:`23882`.)
 
+* Remove ``__class_getitem__`` method from :class:`pathlib.PurePath`,
+  because it was not used and added by mistake in previous versions.
+  (Contributed by Nikita Sobolev in :issue:`46483`.)
 
 Porting to Python 3.11
 ======================
@@ -608,6 +597,12 @@ Changes in the Python API
   of sorting simply isn't well-defined in the absence of a total ordering
   on list elements.
 
+* :mod:`calendar`: The :class:`calendar.LocaleTextCalendar` and
+  :class:`calendar.LocaleHTMLCalendar` classes now use
+  :func:`locale.getlocale`, instead of using :func:`locale.getdefaultlocale`,
+  if no locale is specified.
+  (Contributed by Victor Stinner in :issue:`46659`.)
+
 
 Build Changes
 =============
@@ -623,6 +618,12 @@ Build Changes
   ``isinf()``, ``isnan()``, ``round()``.
   (Contributed by Victor Stinner in :issue:`45440`.)
 
+* Building Python now requires a C99 ``<math.h>`` header file providing
+  a ``NAN`` constant, or the ``__builtin_nan()`` built-in function. If a
+  platform does not support Not-a-Number (NaN), the ``Py_NO_NAN`` macro can be
+  defined in the ``pyconfig.h`` file.
+  (Contributed by Victor Stinner in :issue:`46640`.)
+
 * Freelists for object structs can now be disabled. A new :program:`configure`
   option :option:`!--without-freelists` can be used to disable all freelists
   except empty tuple singleton.
@@ -669,6 +670,11 @@ C API Changes
   fields of the result from the exception instance (the ``value`` field).
   (Contributed by Irit Katriel in :issue:`45711`.)
 
+* :c:struct:`_frozen` has a new ``is_package`` field to indicate whether
+  or not the frozen module is a package.  Previously, a negative value
+  in the ``size`` field was the indicator.  Now only non-negative values
+  be used for ``size``.
+  (Contributed by Kumar Aditya in :issue:`46608`.)
 
 New Features
 ------------
@@ -688,6 +694,26 @@ New Features
   :c:macro:`PY_VERSION_HEX`.
   (Contributed by  Gabriele N. Tornetta in :issue:`43931`.)
 
+* :c:type:`Py_buffer` and APIs are now part of the limited API and the stable
+  ABI:
+
+  * :c:func:`PyObject_CheckBuffer`
+  * :c:func:`PyObject_GetBuffer`
+  * :c:func:`PyBuffer_GetPointer`
+  * :c:func:`PyBuffer_SizeFromFormat`
+  * :c:func:`PyBuffer_ToContiguous`
+  * :c:func:`PyBuffer_FromContiguous`
+  * :c:func:`PyBuffer_CopyData`
+  * :c:func:`PyBuffer_IsContiguous`
+  * :c:func:`PyBuffer_FillContiguousStrides`
+  * :c:func:`PyBuffer_FillInfo`
+  * :c:func:`PyBuffer_Release`
+  * :c:func:`PyMemoryView_FromBuffer`
+  * :c:member:`~PyBufferProcs.bf_getbuffer` and
+    :c:member:`~PyBufferProcs.bf_releasebuffer` type slots
+
+  (Contributed by Christian Heimes in :issue:`45459`.)
+
 
 Porting to Python 3.11
 ----------------------
@@ -790,27 +816,38 @@ Porting to Python 3.11
   which are not available in the limited C API.
   (Contributed by Victor Stinner in :issue:`46007`.)
 
-* Changes of the :c:type:`PyFrameObject` structure members:
+* Changes of the private :c:type:`PyFrameObject` structure members.
+
+  While the documentation notes that the fields of ``PyFrameObject`` are
+  subject to change at any time, they have been stable for a long time
+  and were used in several popular extensions.
+  In Python 3.11, the frame struct was reorganized to allow performance
+  optimizations. Rather than reading the fields directly, extensions should
+  use functions:
 
   * ``f_code``: removed, use :c:func:`PyFrame_GetCode` instead.
     Warning: the function returns a :term:`strong reference`, need to call
     :c:func:`Py_DECREF`.
-  * ``f_back``: changed, use :c:func:`PyFrame_GetBack`.
+  * ``f_back``: changed (see below), use :c:func:`PyFrame_GetBack`.
   * ``f_builtins``: removed,
-    use ``PyObject_GetAttrString(frame, "f_builtins")``.
+    use ``PyObject_GetAttrString((PyObject*)frame, "f_builtins")``.
   * ``f_globals``: removed,
-    use ``PyObject_GetAttrString(frame, "f_globals")``.
+    use ``PyObject_GetAttrString((PyObject*)frame, "f_globals")``.
   * ``f_locals``: removed,
-    use ``PyObject_GetAttrString(frame, "f_locals")``.
+    use ``PyObject_GetAttrString((PyObject*)frame, "f_locals")``.
   * ``f_lasti``: removed,
-    use ``PyObject_GetAttrString(frame, "f_lasti")``.
-  * ``f_valuesstack``: removed.
-  * ``f_stackdepth``: removed.
-  * ``f_gen``: removed.
-  * ``f_iblock``: removed.
-  * ``f_state``: removed.
-  * ``f_blockstack``: removed.
-  * ``f_localsplus``: removed.
+    use ``PyObject_GetAttrString((PyObject*)frame, "f_lasti")``.
+
+  The following fields were removed entirely, as they were details
+  of the old implementation:
+
+  * ``f_valuesstack``
+  * ``f_stackdepth``
+  * ``f_gen``
+  * ``f_iblock``
+  * ``f_state``
+  * ``f_blockstack``
+  * ``f_localsplus``
 
   The Python frame object is now created lazily. A side effect is that the
   ``f_back`` member must not be accessed directly, since its value is now also
@@ -961,3 +998,8 @@ Removed
   worked since the :c:type:`PyWeakReference` structure is opaque in the
   limited C API.
   (Contributed by Victor Stinner in :issue:`35134`.)
+
+* Remove the ``PyHeapType_GET_MEMBERS()`` macro. It was exposed in the
+  public C API by mistake, it must only be used by Python internally.
+  Use the ``PyTypeObject.tp_members`` member instead.
+  (Contributed by Victor Stinner in :issue:`40170`.)

From e4b289ac07fbc005198b09a379fd0f1f54aa2b8b Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Fri, 11 Feb 2022 09:37:10 +0000
Subject: [PATCH 27/28] Remove commented-out line

---
 Lib/idlelib/idle_test/test_util.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 29e9b9a588cffe..20721fe980c784 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,7 +1,6 @@
 """Test util, coverage 100%"""
 
 import unittest
-#from unittest import mock
 from idlelib import util
 
 

From 4931b3f17b9338cfe1045762208c24536d16c570 Mon Sep 17 00:00:00 2001
From: Terry Jan Reedy <tjreedy@udel.edu>
Date: Sat, 12 Feb 2022 14:24:21 -0500
Subject: [PATCH 28/28] Final tweaks.

---
 Lib/idlelib/NEWS.txt                                      | 3 +++
 Lib/idlelib/idle_test/test_iomenu.py                      | 8 ++++----
 Lib/idlelib/idle_test/test_util.py                        | 1 -
 .../next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst    | 2 +-
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index 0bfadfd81e2dd4..441ec41ed76b2c 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -4,6 +4,9 @@ Released on 2022-10-03
 =========================
 
 
+bpo-28950: Apply IDLE syntax highlighting to `.pyi` files.  Add util.py
+for common components.  Patch by Alex Waygood and Terry Jan Reedy.
+
 bpo-46630: Make query dialogs on Windows start with a cursor in the
 entry box.
 
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 849863d9a90acb..e338893c09e6a1 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -45,7 +45,7 @@ def test_fixnewlines_end(self):
         eq(fix(), 'a'+io.eol_convention)
 
 
-def _extension_is_in_IOBinding_dot_filetypes(extension):
+def _extension_in_filetypes(extension):
     return any(
         f'*{extension}' in filetype_tuple[1]
         for filetype_tuple in iomenu.IOBinding.filetypes
@@ -57,14 +57,14 @@ def test_python_source_files(self):
         for extension in util.py_extensions:
             with self.subTest(extension=extension):
                 self.assertTrue(
-                    _extension_is_in_IOBinding_dot_filetypes(extension)
+                    _extension_in_filetypes(extension)
                 )
 
     def test_text_files(self):
-        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes('.txt'))
+        self.assertTrue(_extension_in_filetypes('.txt'))
 
     def test_all_files(self):
-        self.assertTrue(_extension_is_in_IOBinding_dot_filetypes(''))
+        self.assertTrue(_extension_in_filetypes(''))
 
 
 if __name__ == '__main__':
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index 29e9b9a588cffe..20721fe980c784 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -1,7 +1,6 @@
 """Test util, coverage 100%"""
 
 import unittest
-#from unittest import mock
 from idlelib import util
 
 
diff --git a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
index bad30b0f6f31a1..2b5170c7631d24 100644
--- a/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
+++ b/Misc/NEWS.d/next/IDLE/2021-10-14-16-55-03.bpo-45447.FhiH5P.rst
@@ -1,2 +1,2 @@
-IDLE now applies syntax highlighting to `.pyi` files. Patch by Alex Waygood
+Apply IDLE syntax highlighting to `.pyi` files. Patch by Alex Waygood
 and Terry Jan Reedy.