gh-121249: deprecate support for complex types in the struct module

Author: skirpichev

Doc/deprecations/pending-removal-in-3.17.rst

@@ -37,6 +37,15 @@ Pending removal in Python 3.17
     is deprecated and scheduled for removal in Python 3.17.
     (Contributed by Stan Ulbrych in :gh:`136702`.)
 
+
+* :mod:`struct`:
+
+  - Support the :c:expr:`float complex` and :c:expr:`double complex` C types in
+    the :mod:`struct` module (formatting characters ``'F'`` and ``'D'``
+    respectively).
+    (Contributed by Sergey B Kirpichev in :gh:`121249`.)
+
+
 * :mod:`typing`:
 
   - Before Python 3.14, old-style unions were implemented using the private class

Doc/library/struct.rst

@@ -280,6 +280,9 @@ platform-dependent.
 .. versionchanged:: 3.14
    Added support for the ``'F'`` and ``'D'`` formats.
 
+.. deprecated-removed:: 3.15 3.17
+   Support for the ``'F'`` and ``'D'`` formats.
+
 .. seealso::
 
    The :mod:`array` and :ref:`ctypes <ctypes-fundamental-data-types>` modules,

Doc/whatsnew/3.15.rst

@@ -1950,6 +1950,12 @@ New deprecations
 
     (Contributed by Sergey B Kirpichev and Serhiy Storchaka in :gh:`143715`.)
 
+  - Support the :c:expr:`float complex` and :c:expr:`double complex` C types in
+    the :mod:`struct` module (formatting characters ``'F'`` and ``'D'``
+    respectively).
+    (Contributed by Sergey B Kirpichev in :gh:`121249`.)
+
+
 * :mod:`typing`:
 
   * The following statements now cause ``DeprecationWarning``\ s to be emitted

Misc/NEWS.d/next/Library/2026-05-04-05-22-48.gh-issue-121249.XN06Fd.rst

@@ -0,0 +1,2 @@
+Deprecate support for complex types in the :mod:`struct` module (formatting
+characters ``'F'`` and ``'D'`` respectively).