bpo-44404: tkinter `after` support callable classes (GH-26812)

Lib/tkinter/__init__.py

@@ -841,7 +841,11 @@ def callit():
                         self.deletecommand(name)
                     except TclError:
                         pass
-            callit.__name__ = func.__name__
+            try:
+                callit.__name__ = func.__name__
+            except AttributeError:
+                # Required for callable classes (bpo-44404)
+                callit.__name__ = type(func).__name__
             name = self._register(callit)
             return self.tk.call('after', ms, name)
 

Lib/tkinter/test/test_tkinter/test_misc.py

@@ -1,3 +1,4 @@
+import functools
 import unittest
 import tkinter
 import enum
@@ -98,6 +99,12 @@ def callback(start=0, step=1):
         with self.assertRaises(tkinter.TclError):
             root.tk.call(script)
 
+        # Call with a callable class
+        count = 0
+        timer1 = root.after(0, functools.partial(callback, 42, 11))
+        root.update()  # Process all pending events.
+        self.assertEqual(count, 53)
+
     def test_after_idle(self):
         root = self.root
 

Misc/NEWS.d/next/Library/2021-06-20-19-01-11.bpo-44404.McfrYB.rst

@@ -0,0 +1 @@
+:mod:`tkinter`'s ``after()`` method now supports callables without the ``__name__`` attribute.