python · vstinner · Aug 8, 2025 · Jul 31, 2025 · Aug 1, 2025 · Aug 1, 2025
diff --git a/Doc/c-api/complex.rst b/Doc/c-api/complex.rst
@@ -118,6 +118,16 @@ Complex Numbers as Python Objects

   This subtype of :c:type:`PyObject` represents a Python complex number object.

+   .. c:member:: Py_complex cval
+
+      The complex number value, using the C :c:type:`Py_complex` representation.
+
+      .. deprecated-removed:: next 3.20
+         Use :c:func:`PyComplex_AsCComplex` and
+         :c:func:`PyComplex_FromCComplex` to convert a
+         Python complex number to/from the C :c:type:`Py_complex`
+         representation.
+

 .. c:var:: PyTypeObject PyComplex_Type


diff --git a/Doc/deprecations/c-api-pending-removal-in-3.20.rst b/Doc/deprecations/c-api-pending-removal-in-3.20.rst
@@ -0,0 +1,7 @@
+Pending removal in Python 3.20
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* The ``cval`` field in :c:type:`PyComplexObject` (:gh:`128813`).
+  Use :c:func:`PyComplex_AsCComplex` and :c:func:`PyComplex_FromCComplex`
+  to convert a Python complex number to/from the C :c:type:`Py_complex`
+  representation.
diff --git a/Doc/deprecations/index.rst b/Doc/deprecations/index.rst
@@ -18,4 +18,6 @@ C API deprecations

 .. include:: c-api-pending-removal-in-3.18.rst

+.. include:: c-api-pending-removal-in-3.20.rst
+
 .. include:: c-api-pending-removal-in-future.rst
@@ -570,6 +570,13 @@ Deprecated C APIs
  signed integer type of the same size is now deprecated.
  (Contributed by Serhiy Storchaka in :gh:`132629`.)

+* Deprecate :c:member:`~PyComplexObject.cval` field of the the
+  :c:type:`PyComplexObject` type.
+  Use :c:func:`PyComplex_AsCComplex` and :c:func:`PyComplex_FromCComplex`
+  to convert a Python complex number to/from the C :c:type:`Py_complex`
+  representation.
+  (Contributed by Sergey B Kirpichev in :gh:`128813`.)
+
 * Functions :c:func:`_Py_c_sum`, :c:func:`_Py_c_diff`, :c:func:`_Py_c_neg`,
  :c:func:`_Py_c_prod`, :c:func:`_Py_c_quot`, :c:func:`_Py_c_pow` and
  :c:func:`_Py_c_abs` are :term:`soft deprecated`.

diff --git a/Misc/NEWS.d/next/C_API/2025-07-31-04-30-42.gh-issue-128813.opL-Pv.rst b/Misc/NEWS.d/next/C_API/2025-07-31-04-30-42.gh-issue-128813.opL-Pv.rst
@@ -1,4 +1,5 @@
 Functions :c:func:`_Py_c_sum`, :c:func:`_Py_c_diff`, :c:func:`_Py_c_neg`,
-:c:func:`_Py_c_prod`, :c:func:`_Py_c_quot`, :c:func:`_Py_c_pow` and
-previously undocumented :c:func:`_Py_c_abs` are :term:`soft deprecated`.
+:c:func:`_Py_c_prod`, :c:func:`_Py_c_quot`, :c:func:`_Py_c_pow` and previously
+undocumented :c:func:`_Py_c_abs` are :term:`soft deprecated`.  Deprecate also
+:c:member:`~PyComplexObject.cval` field of the :c:type:`PyComplexObject` type.
 Patch by Sergey B Kirpichev.