tempfile.SpooledTemporaryFile: inherit from IOBase on 3.11 (#7802)

python/cpython#29560

Co-authored-by: Alex Waygood <[email protected]>

Author: JelleZijlstra

stdlib/tempfile.pyi

@@ -1,6 +1,7 @@
+import io
 import os
 import sys
-from _typeshed import Self
+from _typeshed import Self, WriteableBuffer
 from collections.abc import Iterable, Iterator
 from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, overload
@@ -217,9 +218,14 @@ class _TemporaryFileWrapper(Generic[AnyStr], IO[AnyStr]):
     def write(self, s: AnyStr) -> int: ...
     def writelines(self, lines: Iterable[AnyStr]) -> None: ...
 
-# It does not actually derive from IO[AnyStr], but it does implement the
-# protocol.
-class SpooledTemporaryFile(IO[AnyStr]):
+if sys.version_info >= (3, 11):
+    _SpooledTemporaryFileBase = io.IOBase
+else:
+    _SpooledTemporaryFileBase = object
+
+# It does not actually derive from IO[AnyStr], but it does mostly behave
+# like one.
+class SpooledTemporaryFile(IO[AnyStr], _SpooledTemporaryFileBase):
     @property
     def encoding(self) -> str: ...  # undocumented
     @property
@@ -318,20 +324,28 @@ class SpooledTemporaryFile(IO[AnyStr]):
     def fileno(self) -> int: ...
     def flush(self) -> None: ...
     def isatty(self) -> bool: ...
-    def read(self, n: int = ...) -> AnyStr: ...
-    def readline(self, limit: int = ...) -> AnyStr: ...
-    def readlines(self, hint: int = ...) -> list[AnyStr]: ...
+    if sys.version_info >= (3, 11):
+        # These three work only if the SpooledTemporaryFile is opened in binary mode,
+        # because the underlying object in text mode does not have these methods.
+        def read1(self, __size: int = ...) -> AnyStr: ...
+        def readinto(self, b: WriteableBuffer) -> int: ...
+        def readinto1(self, b: WriteableBuffer) -> int: ...
+        def detach(self) -> io.RawIOBase: ...
+
+    def read(self, __n: int = ...) -> AnyStr: ...
+    def readline(self, __limit: int | None = ...) -> AnyStr: ...  # type: ignore[override]
+    def readlines(self, __hint: int = ...) -> list[AnyStr]: ...  # type: ignore[override]
     def seek(self, offset: int, whence: int = ...) -> int: ...
     def tell(self) -> int: ...
     def truncate(self, size: int | None = ...) -> None: ...  # type: ignore[override]
     def write(self, s: AnyStr) -> int: ...
-    def writelines(self, iterable: Iterable[AnyStr]) -> None: ...
-    def __iter__(self) -> Iterator[AnyStr]: ...
-    # Other than the following methods, which do not exist on SpooledTemporaryFile
+    def writelines(self, iterable: Iterable[AnyStr]) -> None: ...  # type: ignore[override]
+    def __iter__(self) -> Iterator[AnyStr]: ...  # type: ignore[override]
+    # These exist at runtime only on 3.11+.
     def readable(self) -> bool: ...
     def seekable(self) -> bool: ...
     def writable(self) -> bool: ...
-    def __next__(self) -> AnyStr: ...
+    def __next__(self) -> AnyStr: ...  # type: ignore[override]
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 

tests/stubtest_allowlists/py311.txt

@@ -149,10 +149,6 @@ subprocess.getstatusoutput
 symtable.SymbolTable.has_exec
 sys.UnraisableHookArgs  # Not exported from sys
 sys.exception
-tempfile.SpooledTemporaryFile.detach
-tempfile.SpooledTemporaryFile.read1
-tempfile.SpooledTemporaryFile.readinto
-tempfile.SpooledTemporaryFile.readinto1
 tkinter._VersionInfoType.__doc__
 traceback.StackSummary.format_frame_summary
 traceback.TracebackException.__init__