gh-68966: Deprecate the mailcap module

Doc/library/mailcap.rst

@@ -6,6 +6,9 @@
 
 **Source code:** :source:`Lib/mailcap.py`
 
+.. deprecated-removed:: 3.11 3.13
+   See the :mod:`mimetypes` module for an alternative.
+
 --------------
 
 Mailcap files are used to configure how MIME-aware applications such as mail

Doc/whatsnew/3.11.rst

@@ -985,6 +985,11 @@ Deprecated
   be able to parse Python 3.10 or newer. See the :pep:`617` (New PEG parser for
   CPython).  (Contributed by Victor Stinner in :issue:`40360`.)
 
+* The :mod:`mailcap` module is now deprecated and will be removed in Python
+  3.13. See :pep:`594` for the rationale and the :mod:`mimetypes` module for an
+  alternative.
+  (Contributed by Victor Stinner in :gh:`68966`.)
+
 * Undocumented modules ``sre_compile``, ``sre_constants`` and ``sre_parse``
   are now deprecated.
   (Contributed by Serhiy Storchaka in :issue:`47152`.)

Lib/mailcap.py

@@ -6,6 +6,12 @@
 __all__ = ["getcaps","findmatch"]
 
 
+_DEPRECATION_MSG = ('The {name} module is deprecated and will be removed in '
+                    'Python {remove}. See the mimetypes module for an '
+                    'alternative.')
+warnings._deprecated(__name__, _DEPRECATION_MSG, remove=(3, 13))
+
+
 def lineno_sort_key(entry):
     # Sort in ascending order, with unspecified entries at the end
     if 'lineno' in entry:

Lib/test/test_mailcap.py

@@ -1,10 +1,17 @@
-import mailcap
-import os
 import copy
+import os
+import sys
 import test.support
-from test.support import os_helper
 import unittest
-import sys
+import warnings
+from test.support import os_helper
+
+
+with warnings.catch_warnings():
+    # mailcap is deprecated
+    warnings.simplefilter('ignore', DeprecationWarning)
+    import mailcap
+
 
 # Location of mailcap file
 MAILCAPFILE = test.support.findfile("mailcap.txt")

Misc/NEWS.d/next/Library/2022-04-26-09-09-07.gh-issue-68966.roapI2.rst

@@ -0,0 +1,3 @@
+The :mod:`mailcap` module is now deprecated and will be removed in Python 3.13.
+See :pep:`594` for the rationale and the :mod:`mimetypes` module for an
+alternative. Patch by Victor Stinner.