Issue #9384: python -m tkinter will now display a simple demo applet.

Doc/library/tkinter.rst

@@ -9,7 +9,9 @@
 The :mod:`tkinter` package ("Tk interface") is the standard Python interface to
 the Tk GUI toolkit.  Both Tk and :mod:`tkinter` are available on most Unix
 platforms, as well as on Windows systems.  (Tk itself is not part of Python; it
-is maintained at ActiveState.)
+is maintained at ActiveState.) You can check that :mod:`tkinter` is properly
+installed on your system by running ``python -m tkinter`` from the command line;
+this should open a window demonstrating a simple Tk interface.
 
 .. seealso::
 

Lib/tkinter/__main__.py

+"""Main entry point"""
+
+import sys
+if sys.argv[0].endswith("__main__.py"):
+    sys.argv[0] = "python -m tkinter"
+from . import _test as main
+main()

Misc/NEWS

@@ -473,6 +473,8 @@ C-API
 Library
 -------
 
+- Issue #9384: python -m tkinter will now display a simple demo applet.
+
 - The default size of the re module's compiled regular expression cache has
   been increased from 100 to 500 and the cache replacement policy has changed
   from simply clearing the entire cache on overflow to randomly forgetting 20%