python · Siyet · Apr 6, 2026 · Apr 6, 2026 · Apr 6, 2026 · Apr 7, 2026
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
@@ -1547,17 +1547,6 @@ iterations of the loop.
       ``i`` is no longer offset by the length of :attr:`~codeobject.co_varnames`.
 
 
-.. opcode:: DELETE_DEREF (i)
-
-   Empties the cell contained in slot ``i`` of the "fast locals" storage.
-   Used by the :keyword:`del` statement.
-
-   .. versionadded:: 3.2
-
-   .. versionchanged:: 3.11
-      ``i`` is no longer offset by the length of :attr:`~codeobject.co_varnames`.
-
-
 .. opcode:: COPY_FREE_VARS (n)
 
    Copies the ``n`` :term:`free (closure) variables <closure variable>` from the closure

@@ -1 +1,2 @@
 # HTML IDs excluded from the check-html-ids.py check.
+library/dis.html: opcode-DELETE_DEREF
@@ -1446,6 +1446,15 @@ Additional optimizations for AArch64 contributed by Mark Shannon and
 Diego Russo in :gh:`140683` and :gh:`142305`.)
 
 
+CPython bytecode changes
+========================
+
+* Removed the :opcode:`!DELETE_DEREF` opcode. Deletion of closure variables
+  is now compiled as :opcode:`LOAD_DEREF`, :opcode:`POP_TOP`,
+  :opcode:`PUSH_NULL`, :opcode:`STORE_DEREF`.
+  (Contributed by Aleksandr Tseluyko in :gh:`145858`.)
+
+
 Removed
 ========
 

diff --git a/Include/internal/pycore_magic_number.h b/Include/internal/pycore_magic_number.h
@@ -294,6 +294,7 @@ Known values:
     Python 3.15a4 3661 (Lazy imports IMPORT_NAME opcode changes)
     Python 3.15a8 3662 (Add counter to RESUME)
     Python 3.15a8 3663 (Merge GET_ITER and GET_YIELD_FROM_ITER. Modify SEND to make it a bit more like FOR_ITER)
+    Python 3.15a8 3664 (Remove DELETE_DEREF opcode)
 
 
     Python 3.16 will start with 3700
@@ -307,7 +308,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3663
+#define PYC_MAGIC_NUMBER 3664
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \

diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
Original file line number	Diff line number	Diff line change
		@@ -1 +1,2 @@
		# HTML IDs excluded from the check-html-ids.py check.
		library/dis.html: opcode-DELETE_DEREF
Copy link Copy Markdown Member StanFromIreland Apr 6, 2026 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I would suggest instead having a 'CPython bytecode changes' section in the what's new, like we had for 3.14, and redirecting to there, but this isn't my area so I'll leave it to the experts. Copy link Copy Markdown Author Siyet Apr 7, 2026 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. Good point, thanks! Added a "CPython bytecode changes" section to `Doc/whatsnew/3.15.rst` following the 3.14 pattern. Kept `removed-ids.txt` as well since it's needed for the CI HTML ID check independently.