Replace io.BytesIO in type hints

.coveragerc

@@ -12,6 +12,9 @@ exclude_also =
     except ImportError
     if TYPE_CHECKING:
     @abc.abstractmethod
+    # Empty bodies in protocols or abstract methods
+    ^\s*def [a-zA-Z0-9_]+\(.*\)(\s*->.*)?:\s*\.\.\.(\s*#.*)?$
+    ^\s*\.\.\.(\s*#.*)?$
 
 [run]
 omit =

Tests/test_image.py

@@ -162,8 +162,6 @@ def test_stringio(self) -> None:
                 pass
 
     def test_pathlib(self, tmp_path: Path) -> None:
-        from PIL.Image import Path
-
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
             assert im.mode == "P"
             assert im.size == (10, 10)

Tests/test_util.py

@@ -1,29 +1,16 @@
 from __future__ import annotations
 
-from pathlib import Path
+from pathlib import Path, PurePath
 
 import pytest
 
 from PIL import _util
 
 
-def test_is_path() -> None:
-    # Arrange
-    fp = "filename.ext"
-
-    # Act
-    it_is = _util.is_path(fp)
-
-    # Assert
-    assert it_is
-
-
-def test_path_obj_is_path() -> None:
-    # Arrange
-    from pathlib import Path
-
-    test_path = Path("filename.ext")
-
+@pytest.mark.parametrize(
+    "test_path", ["filename.ext", Path("filename.ext"), PurePath("filename.ext")]
+)
+def test_is_path(test_path) -> None:
     # Act
     it_is = _util.is_path(test_path)
 

docs/reference/internal_design.rst

@@ -1,5 +1,5 @@
-Internal Reference Docs
-=======================
+Internal Reference
+==================
 
 .. toctree::
   :maxdepth: 2

docs/reference/internal_modules.rst

@@ -33,6 +33,14 @@ Internal Modules
 Provides a convenient way to import type hints that are not available
 on some Python versions.
 
+.. py:class:: StrOrBytesPath
+
+    Typing alias.
+
+.. py:class:: SupportsRead
+
+    An object that supports the read method.
+
 .. py:data:: TypeGuard
     :value: typing.TypeGuard
 

docs/reference/open_files.rst

@@ -3,7 +3,7 @@
 File Handling in Pillow
 =======================
 
-When opening a file as an image, Pillow requires a filename, ``pathlib.Path``
+When opening a file as an image, Pillow requires a filename, ``os.PathLike``
 object, or a file-like object. Pillow uses the filename or ``Path`` to open a
 file, so for the rest of this article, they will all be treated as a file-like
 object.

src/PIL/GdImageFile.py

@@ -27,11 +27,12 @@ class is not registered for use with :py:func:`PIL.Image.open()`.  To open a
 """
 from __future__ import annotations
 
-from io import BytesIO
+from typing import IO
 
 from . import ImageFile, ImagePalette, UnidentifiedImageError
 from ._binary import i16be as i16
 from ._binary import i32be as i32
+from ._typing import StrOrBytesPath
 
 
 class GdImageFile(ImageFile.ImageFile):
@@ -80,7 +81,7 @@ def _open(self) -> None:
         ]
 
 
-def open(fp: BytesIO, mode: str = "r") -> GdImageFile:
+def open(fp: StrOrBytesPath | IO[bytes], mode: str = "r") -> GdImageFile:
     """
     Load texture from a GD image file.
 

src/PIL/Image.py

@@ -40,7 +40,6 @@
 import warnings
 from collections.abc import Callable, MutableMapping
 from enum import IntEnum
-from pathlib import Path
 from types import ModuleType
 from typing import IO, TYPE_CHECKING, Any
 
@@ -2383,7 +2382,7 @@ def save(self, fp, format=None, **params) -> None:
         implement the ``seek``, ``tell``, and ``write``
         methods, and be opened in binary mode.
 
-        :param fp: A filename (string), pathlib.Path object or file object.
+        :param fp: A filename (string), os.PathLike object or file object.
         :param format: Optional format override.  If omitted, the
            format to use is determined from the filename extension.
            If a file object was used instead of a filename, this
@@ -2398,11 +2397,8 @@ def save(self, fp, format=None, **params) -> None:
 
         filename: str | bytes = ""
         open_fp = False
-        if isinstance(fp, Path):
-            filename = str(fp)
-            open_fp = True
-        elif isinstance(fp, (str, bytes)):
-            filename = fp
+        if is_path(fp):
+            filename = os.path.realpath(os.fspath(fp))
             open_fp = True
         elif fp == sys.stdout:
             try:
@@ -3225,7 +3221,7 @@ def open(fp, mode="r", formats=None) -> Image:
     :py:meth:`~PIL.Image.Image.load` method).  See
     :py:func:`~PIL.Image.new`. See :ref:`file-handling`.
 
-    :param fp: A filename (string), pathlib.Path object or a file object.
+    :param fp: A filename (string), os.PathLike object or a file object.
        The file object must implement ``file.read``,
        ``file.seek``, and ``file.tell`` methods,
        and be opened in binary mode. The file object will also seek to zero

src/PIL/ImageFont.py

@@ -33,10 +33,10 @@
 import warnings
 from enum import IntEnum
 from io import BytesIO
-from pathlib import Path
 from typing import BinaryIO
 
 from . import Image
+from ._typing import StrOrBytesPath
 from ._util import is_directory, is_path
 
 
@@ -193,7 +193,7 @@ class FreeTypeFont:
 
     def __init__(
         self,
-        font: bytes | str | Path | BinaryIO | None = None,
+        font: StrOrBytesPath | BinaryIO | None = None,
         size: float = 10,
         index: int = 0,
         encoding: str = "",
@@ -230,8 +230,7 @@ def load_from_bytes(f):
             )
 
         if is_path(font):
-            if isinstance(font, Path):
-                font = str(font)
+            font = os.path.realpath(os.fspath(font))
             if sys.platform == "win32":
                 font_bytes_path = font if isinstance(font, bytes) else font.encode()
                 try:

src/PIL/MpegImagePlugin.py

@@ -14,17 +14,16 @@
 #
 from __future__ import annotations
 
-from io import BytesIO
-
 from . import Image, ImageFile
 from ._binary import i8
+from ._typing import SupportsRead
 
 #
 # Bitstream parser
 
 
 class BitStream:
-    def __init__(self, fp: BytesIO) -> None:
+    def __init__(self, fp: SupportsRead[bytes]) -> None:
         self.fp = fp
         self.bits = 0
         self.bitbuffer = 0

src/PIL/_typing.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+import os
 import sys
-from typing import Sequence, Union
+from typing import Protocol, Sequence, TypeVar, Union
 
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
@@ -19,4 +20,14 @@ def __class_getitem__(cls, item: Any) -> type[bool]:
 Coords = Union[Sequence[float], Sequence[Sequence[float]]]
 
 
-__all__ = ["TypeGuard"]
+_T_co = TypeVar("_T_co", covariant=True)
+
+
+class SupportsRead(Protocol[_T_co]):
+    def read(self, __length: int = ...) -> _T_co: ...
+
+
+StrOrBytesPath = Union[str, bytes, "os.PathLike[str]", "os.PathLike[bytes]"]
+
+
+__all__ = ["TypeGuard", "StrOrBytesPath", "SupportsRead"]

src/PIL/_util.py

@@ -1,17 +1,16 @@
 from __future__ import annotations
 
 import os
-from pathlib import Path
 from typing import Any, NoReturn
 
-from ._typing import TypeGuard
+from ._typing import StrOrBytesPath, TypeGuard
 
 
-def is_path(f: Any) -> TypeGuard[bytes | str | Path]:
-    return isinstance(f, (bytes, str, Path))
+def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
+    return isinstance(f, (bytes, str, os.PathLike))
 
 
-def is_directory(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_directory(f: Any) -> TypeGuard[StrOrBytesPath]:
     """Checks if an object is a string, and that it points to a directory."""
     return is_path(f) and os.path.isdir(f)