PEP 784: Mark as Accepted (#4387)

* PEP 784: Remove deprecation and removal timeline

As requested by the Steering Council

* Add suggestion from Barry

Co-authored-by: Barry Warsaw <barry@python.org>

* Mark PEP 784 accepted

* Add a second underline for resolution link

* Use shorter form of discuss URL

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

* Add no sooner than verbiage

* Mention the compression sub-modules should be canonical

* Include statement on documentation

Co-authored-by: "Gregory P. Smith" <greg@krypto.org>

* Update _compression rename to reflect review

---------

Co-authored-by: Barry Warsaw <barry@python.org>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: "Gregory P. Smith" <greg@krypto.org>

Author: 4 people

peps/pep-0784.rst

@@ -3,12 +3,13 @@ Title: Adding Zstandard to the standard library
 Author: Emma Harper Smith <emma@python.org>
 Sponsor: Gregory P. Smith <greg@krypto.org>
 Discussions-To: https://discuss.python.org/t/87377
-Status: Draft
+Status: Accepted
 Type: Standards Track
 Created: 06-Apr-2025
 Python-Version: 3.14
 Post-History:
   `07-Apr-2025 <https://discuss.python.org/t/87377>`__,
+Resolution: `25-Apr-2025 <https://discuss.python.org/t/87377/138>`__
 
 
 Abstract
@@ -115,9 +116,8 @@ Both the ``zstd`` and ``zstandard`` import names are claimed by projects on
 PyPI. To avoid breaking users of one of the existing bindings, this PEP
 proposes introducing a new namespace for compression libraries,
 ``compression``. This name is already reserved on PyPI for use in the
-standard library. The new Zstandard module will be ``compression.zstd``.
-Other compression modules will be re-exported to the ``compression`` namespace
-and their current import names will be deprecated.
+standard library. The new Zstandard module will be named ``compression.zstd``.
+Other compression modules will be re-exported in the new ``compression`` package.
 
 Providing a common namespace for compression modules has several advantages.
 First, it reduces user confusion about where to find compression modules.
@@ -220,38 +220,25 @@ Other compression modules
 New import names ``compression.lzma``, ``compression.bz2``,
 ``compression.gzip`` and ``compression.zlib`` will be introduced in Python 3.14
 re-exporting the contents of the existing ``lzma``, ``bz2``, ``gzip`` and
-``zlib`` modules respectively.
+``zlib`` modules respectively. The ``compression`` sub-modules will become
+the canonical import names going forward. The use of the new compression names
+will be promoted over the original top level module names in the Python
+documentation when the minimum supported Python version requirements make
+that feasible.
 
 The ``_compression`` module, given that it is marked private, will be
-immediately renamed to ``compression._common.streams``. The new name was
+immediately renamed to ``compression._common._streams``. The new name was
 selected due to the current contents of the module being I/O related helpers
 for stream APIs (e.g. ``LZMAFile``) in standard library compression modules.
 
-Compression module migration timeline
--------------------------------------
-
-Existing modules will emit a ``DeprecationWarning`` in the Python
-release following the last Python without the ``compression`` module leaving
-support. For example, if the ``compression`` namespace is introduced in 3.14,
-then the ``DeprecationWarnings`` would be emitted in 3.19, the next release
-after 3.13 reaches end of life. These warnings would begin five years after the
-introduction of ``compression`` namespace. In accordance with :pep:`387`, in
-Python 3.24, five years after the ``DeprecationWarnings`` are added and ten
-years after the new ``compression`` namespace is introduced, the existing
-modules will be removed and code must use the ``compression`` sub-modules. The
-documentation for these modules will be updated to discuss the planned
-deprecation and removal timelines.
-
 
 Backwards Compatibility
 =======================
 
-The main compatibility concern is usage of existing standard library
-compression APIs with the existing import names. These names will be
-deprecated in 3.19 and will be removed in 3.24. Given the long coexistence of
-the modules and a 5 year deprecation period, most users will likely migrate to
-the new import names well before then. Additionally, a libCST codemod can be
-provided to automatically rewrite imports, easing the migration.
+This PEP introduces no backwards incompatible changes. There are currently no
+plans to deprecate or remove the existing compression modules. Any deprecation
+or removal of the existing modules is left to a future decision but will occur
+no sooner than 5 years from the acceptance of this PEP.
 
 
 Security Implications
@@ -273,8 +260,8 @@ How to Teach This
 =================
 
 Documentation for the new module is in the reference implementation branch. The
-documentation for other modules will be updated to discuss the deprecation of
-their existing import names, and how to migrate.
+documentation for existing modules will be updated to reference the new names
+as well.
 
 
 Reference Implementation
@@ -284,8 +271,7 @@ The `reference implementation <https://github.com/emmatyping/cpython/tree/zstd>`
 contains the ``_zstd`` C code, the ``compression.zstd`` code, modifications to
 ``tarfile``, ``shutil``, and ``zipfile``, and tests for each new API and
 integration added. It also contains the re-exports of other compression
-modules. Deprecations for the existing import names will be added once a
-decision is reached regarding the open issues.
+modules.
 
 
 Rejected Ideas