gh-93096: Remove CLI interface for difflib (#131099)

Doc/library/cmdline.rst

@@ -11,7 +11,6 @@ The following modules have a command-line interface.
 * :mod:`code`
 * :ref:`compileall <compileall-cli>`
 * :mod:`cProfile`: see :ref:`profile <profile-cli>`
-* :ref:`difflib <difflib-interface>`
 * :ref:`dis <dis-cli>`
 * :mod:`doctest`
 * :mod:`!encodings.rot_13`

Lib/difflib.py

@@ -2060,10 +2060,3 @@ def restore(delta, which):
     for line in delta:
         if line[:2] in prefixes:
             yield line[2:]
-
-def _test():
-    import doctest, difflib
-    return doctest.testmod(difflib)
-
-if __name__ == "__main__":
-    _test()

Misc/NEWS.d/next/Library/2025-03-11-20-35-41.gh-issue-93096.Jdt_8a.rst

@@ -0,0 +1,2 @@
+Removed undocumented CLI ``python -m difflib``. Use ``python -m doctest
+Lib/difflib.py -v`` instead. Patch by Semyon Moroz.