gh-153333: Read tkinter profile scripts with the source file's encoding

Tk.readprofile execed the user's ~/.CLASSNAME.py and ~/.BASENAME.py profile scripts read via open() with no encoding argument, i.e. the locale default encoding. That emits an EncodingWarning under -X warn_default_encoding and mis-decodes a profile whose source carries a PEP 263 coding cookie. Read them with tokenize.open() instead, which decodes using the encoding detected from the file (its coding cookie, else UTF-8), matching how Python reads source. As an incidental effect of using the context-manager form, each script is now closed promptly after reading instead of at garbage collection, removing a ResourceWarning.

Author: tonghuaroot

Lib/test/test_tkinter/test_misc.py

@@ -1,9 +1,11 @@
 import collections.abc
 import functools
+import os
 import platform
 import sys
 import textwrap
 import unittest
+import warnings
 import weakref
 import tkinter
 from tkinter import TclError
@@ -364,6 +366,24 @@ def test_getdouble(self):
         self.assertEqual(self.root.getdouble(3), 3.0)
         self.assertRaises(ValueError, self.root.getdouble, 'spam')
 
+    def test_readprofile(self):
+        # gh-153333: readprofile() reads the profile scripts with the source
+        # file's encoding (here a Latin-1 coding cookie), not the locale
+        # default encoding.
+        name = 'readprofiletest'
+        script = ("# -*- coding: latin-1 -*-\n"
+                  "self.readprofile_result = 'caf\xe9'\n")
+        self.addCleanup(self.root.__dict__.pop, 'readprofile_result', None)
+        with os_helper.temp_dir() as home:
+            with open(os.path.join(home, '.%s.py' % name), 'wb') as f:
+                f.write(script.encode('latin-1'))
+            with os_helper.EnvironmentVarGuard() as env:
+                env['HOME'] = home
+                with warnings.catch_warnings():
+                    warnings.simplefilter('error', EncodingWarning)
+                    self.root.readprofile(name, name)
+        self.assertEqual(self.root.readprofile_result, 'caf\xe9')
+
     def test_getvar(self):
         self.root.setvar('test_var', 'hello')
         self.assertEqual(self.root.getvar('test_var'), 'hello')

Lib/tkinter/__init__.py

@@ -2739,6 +2739,7 @@ def readprofile(self, baseName, className):
         the Tcl Interpreter and calls exec on the contents of .BASENAME.py and
         .CLASSNAME.py if such a file exists in the home directory."""
         import os
+        import tokenize
         if 'HOME' in os.environ: home = os.environ['HOME']
         else: home = os.curdir
         class_tcl = os.path.join(home, '.%s.tcl' % className)
@@ -2750,11 +2751,13 @@ def readprofile(self, baseName, className):
         if os.path.isfile(class_tcl):
             self.tk.call('source', class_tcl)
         if os.path.isfile(class_py):
-            exec(open(class_py).read(), dir)
+            with tokenize.open(class_py) as f:
+                exec(f.read(), dir)
         if os.path.isfile(base_tcl):
             self.tk.call('source', base_tcl)
         if os.path.isfile(base_py):
-            exec(open(base_py).read(), dir)
+            with tokenize.open(base_py) as f:
+                exec(f.read(), dir)
 
     def report_callback_exception(self, exc, val, tb):
         """Report callback exception on sys.stderr.

Misc/NEWS.d/next/Library/2026-07-08-21-15-00.gh-issue-153333.Kp3mZq.rst

@@ -0,0 +1,2 @@
+The ``readprofile`` method of :class:`tkinter.Tk` now reads the user's
+profile scripts using :func:`tokenize.open`.