3.14: PEP-784 compression except zstd (#13992)

stdlib/@tests/stubtest_allowlists/py314.txt

@@ -5,7 +5,6 @@
 _asyncio.all_tasks
 _asyncio.future_add_to_awaited_by
 _asyncio.future_discard_from_awaited_by
-_compression
 _ctypes.POINTER
 _ctypes.byref
 _ctypes.pointer
@@ -69,11 +68,11 @@ builtins.staticmethod.__annotate__
 builtins.staticmethod.__class_getitem__
 code.compile_command
 codeop.compile_command
-compression
-compression.bz2
-compression.gzip
-compression.lzma
-compression.zlib
+compression.gzip.GzipFile.readinto
+compression.gzip.GzipFile.readinto
+compression.gzip.GzipFile.readinto1
+compression.gzip.GzipFile.readinto1
+compression.gzip.compress
 compression.zstd
 concurrent.futures.__all__
 concurrent.futures.InterpreterPoolExecutor

stdlib/@tests/stubtest_allowlists/win32-py314.txt

@@ -23,6 +23,7 @@ asyncio.windows_events.WindowsSelectorEventLoopPolicy
 asyncio.windows_events._DefaultEventLoopPolicy
 asyncio.windows_events._WindowsProactorEventLoopPolicy
 asyncio.windows_events._WindowsSelectorEventLoopPolicy
+compression.zlib.ZLIBNG_VERSION
 ctypes.c_double_complex
 ctypes.c_float_complex
 ctypes.c_longdouble_complex

stdlib/VERSIONS

@@ -28,7 +28,7 @@ _bz2: 3.3-
 _codecs: 3.0-
 _collections_abc: 3.3-
 _compat_pickle: 3.1-
-_compression: 3.5-
+_compression: 3.5-3.13
 _contextvars: 3.7-
 _csv: 3.0-
 _ctypes: 3.0-
@@ -118,6 +118,7 @@ collections: 3.0-
 collections.abc: 3.3-
 colorsys: 3.0-
 compileall: 3.0-
+compression: 3.14-
 concurrent: 3.2-
 configparser: 3.0-
 contextlib: 3.0-

stdlib/_compression.pyi

@@ -1,4 +1,6 @@
-from _typeshed import WriteableBuffer
+# _compression is replaced by compression._common._streams on Python 3.14+ (PEP-784)
+
+from _typeshed import Incomplete, WriteableBuffer
 from collections.abc import Callable
 from io import DEFAULT_BUFFER_SIZE, BufferedIOBase, RawIOBase
 from typing import Any, Protocol
@@ -16,9 +18,9 @@ class DecompressReader(RawIOBase):
     def __init__(
         self,
         fp: _Reader,
-        decomp_factory: Callable[..., object],
+        decomp_factory: Callable[..., Incomplete],
         trailing_error: type[Exception] | tuple[type[Exception], ...] = (),
-        **decomp_args: Any,
+        **decomp_args: Any,  # These are passed to decomp_factory.
     ) -> None: ...
     def readinto(self, b: WriteableBuffer) -> int: ...
     def read(self, size: int = -1) -> bytes: ...

stdlib/bz2.pyi

@@ -1,17 +1,21 @@
-import _compression
+import sys
 from _bz2 import BZ2Compressor as BZ2Compressor, BZ2Decompressor as BZ2Decompressor
-from _compression import BaseStream
 from _typeshed import ReadableBuffer, StrOrBytesPath, WriteableBuffer
 from collections.abc import Iterable
 from typing import IO, Literal, Protocol, SupportsIndex, TextIO, overload
 from typing_extensions import Self, TypeAlias
 
+if sys.version_info >= (3, 14):
+    from compression._common._streams import BaseStream, _Reader
+else:
+    from _compression import BaseStream, _Reader
+
 __all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor", "open", "compress", "decompress"]
 
 # The following attributes and methods are optional:
 # def fileno(self) -> int: ...
 # def close(self) -> object: ...
-class _ReadableFileobj(_compression._Reader, Protocol): ...
+class _ReadableFileobj(_Reader, Protocol): ...
 
 class _WritableFileobj(Protocol):
     def write(self, b: bytes, /) -> object: ...

stdlib/compression/_common/_streams.pyi

@@ -0,0 +1,25 @@
+from _typeshed import Incomplete, WriteableBuffer
+from collections.abc import Callable
+from io import DEFAULT_BUFFER_SIZE, BufferedIOBase, RawIOBase
+from typing import Any, Protocol
+
+BUFFER_SIZE = DEFAULT_BUFFER_SIZE
+
+class _Reader(Protocol):
+    def read(self, n: int, /) -> bytes: ...
+    def seekable(self) -> bool: ...
+    def seek(self, n: int, /) -> Any: ...
+
+class BaseStream(BufferedIOBase): ...
+
+class DecompressReader(RawIOBase):
+    def __init__(
+        self,
+        fp: _Reader,
+        decomp_factory: Callable[..., Incomplete],  # Consider backporting changes to _compression
+        trailing_error: type[Exception] | tuple[type[Exception], ...] = (),
+        **decomp_args: Any,  # These are passed to decomp_factory.
+    ) -> None: ...
+    def readinto(self, b: WriteableBuffer) -> int: ...
+    def read(self, size: int = -1) -> bytes: ...
+    def seek(self, offset: int, whence: int = 0) -> int: ...

stdlib/compression/bz2/__init__.pyi

@@ -0,0 +1 @@
+from bz2 import *

stdlib/compression/gzip/__init__.pyi

@@ -0,0 +1 @@
+from gzip import *

stdlib/compression/lzma/__init__.pyi

@@ -0,0 +1 @@
+from lzma import *

stdlib/compression/zlib/__init__.pyi

@@ -0,0 +1 @@
+from zlib import *

stdlib/gzip.pyi

@@ -1,4 +1,3 @@
-import _compression
 import sys
 import zlib
 from _typeshed import ReadableBuffer, SizedBuffer, StrOrBytesPath
@@ -6,6 +5,11 @@ from io import FileIO, TextIOWrapper
 from typing import Final, Literal, Protocol, overload
 from typing_extensions import TypeAlias
 
+if sys.version_info >= (3, 14):
+    from compression._common._streams import BaseStream, DecompressReader
+else:
+    from _compression import BaseStream, DecompressReader
+
 __all__ = ["BadGzipFile", "GzipFile", "open", "compress", "decompress"]
 
 _ReadBinaryMode: TypeAlias = Literal["r", "rb"]
@@ -84,7 +88,7 @@ class _PaddedFile:
 
 class BadGzipFile(OSError): ...
 
-class GzipFile(_compression.BaseStream):
+class GzipFile(BaseStream):
     myfileobj: FileIO | None
     mode: object
     name: str
@@ -153,7 +157,7 @@ class GzipFile(_compression.BaseStream):
     def seek(self, offset: int, whence: int = 0) -> int: ...
     def readline(self, size: int | None = -1) -> bytes: ...
 
-class _GzipReader(_compression.DecompressReader):
+class _GzipReader(DecompressReader):
     def __init__(self, fp: _ReadableFileobj) -> None: ...
 
 def compress(data: SizedBuffer, compresslevel: int = 9, *, mtime: float | None = None) -> bytes: ...

stdlib/lzma.pyi

@@ -1,4 +1,4 @@
-from _compression import BaseStream
+import sys
 from _lzma import (
     CHECK_CRC32 as CHECK_CRC32,
     CHECK_CRC64 as CHECK_CRC64,
@@ -38,6 +38,11 @@ from _typeshed import ReadableBuffer, StrOrBytesPath
 from typing import IO, Literal, TextIO, overload
 from typing_extensions import Self, TypeAlias
 
+if sys.version_info >= (3, 14):
+    from compression._common._streams import BaseStream
+else:
+    from _compression import BaseStream
+
 __all__ = [
     "CHECK_NONE",
     "CHECK_CRC32",