Replace io.BytesIO in type hints

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 FileDescriptor, StrOrBytesPath
 
 
 class GdImageFile(ImageFile.ImageFile):
@@ -80,7 +81,9 @@ def _open(self) -> None:
         ]
 
 
-def open(fp: BytesIO, mode: str = "r") -> GdImageFile:
+def open(
+    fp: StrOrBytesPath | FileDescriptor | IO[bytes], mode: str = "r"
+) -> GdImageFile:
     """
     Load texture from a GD image file.
 

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) -> None:
         self.fp = fp
         self.bits = 0
         self.bitbuffer = 0

src/PIL/PpmImagePlugin.py

@@ -16,12 +16,13 @@
 from __future__ import annotations
 
 import math
-from io import BytesIO
+from typing import IO
 
 from . import Image, ImageFile
 from ._binary import i16be as i16
 from ._binary import o8
 from ._binary import o32le as o32
+from ._typing import FileDescriptor, StrOrBytesPath
 
 #
 # --------------------------------------------------------------------
@@ -324,7 +325,9 @@ def decode(self, buffer: bytes) -> tuple[int, int]:
 # --------------------------------------------------------------------
 
 
-def _save(im: Image.Image, fp: BytesIO, filename: str) -> None:
+def _save(
+    im: Image.Image, fp: StrOrBytesPath | FileDescriptor | IO[bytes], filename: str
+) -> None:
     if im.mode == "1":
         rawmode, head = "1;I", b"P4"
     elif im.mode == "L":

src/PIL/SgiImagePlugin.py

@@ -24,11 +24,12 @@
 
 import os
 import struct
-from io import BytesIO
+from typing import IO
 
 from . import Image, ImageFile
 from ._binary import i16be as i16
 from ._binary import o8
+from ._typing import FileDescriptor, StrOrBytesPath
 
 
 def _accept(prefix: bytes) -> bool:
@@ -125,7 +126,9 @@ def _open(self) -> None:
             ]
 
 
-def _save(im: Image.Image, fp: BytesIO, filename: str) -> None:
+def _save(
+    im: Image.Image, fp: StrOrBytesPath | FileDescriptor | IO[bytes], filename: str
+) -> None:
     if im.mode not in {"RGB", "RGBA", "L"}:
         msg = "Unsupported SGI image mode"
         raise ValueError(msg)

src/PIL/TgaImagePlugin.py

@@ -18,12 +18,13 @@
 from __future__ import annotations
 
 import warnings
-from io import BytesIO
+from typing import IO
 
 from . import Image, ImageFile, ImagePalette
 from ._binary import i16le as i16
 from ._binary import o8
 from ._binary import o16le as o16
+from ._typing import FileDescriptor, StrOrBytesPath
 
 #
 # --------------------------------------------------------------------
@@ -175,7 +176,9 @@ def load_end(self) -> None:
 }
 
 
-def _save(im: Image.Image, fp: BytesIO, filename: str) -> None:
+def _save(
+    im: Image.Image, fp: StrOrBytesPath | FileDescriptor | IO[bytes], filename: str
+) -> None:
     try:
         rawmode, bits, colormaptype, imagetype = SAVE[im.mode]
     except KeyError as e:

src/PIL/XbmImagePlugin.py

@@ -21,9 +21,10 @@
 from __future__ import annotations
 
 import re
-from io import BytesIO
+from typing import IO
 
 from . import Image, ImageFile
+from ._typing import FileDescriptor, StrOrBytesPath
 
 # XBM header
 xbm_head = re.compile(
@@ -70,7 +71,9 @@ def _open(self) -> None:
         self.tile = [("xbm", (0, 0) + self.size, m.end(), None)]
 
 
-def _save(im: Image.Image, fp: BytesIO, filename: str) -> None:
+def _save(
+    im: Image.Image, fp: StrOrBytesPath | FileDescriptor | IO[bytes], filename: str
+) -> None:
     if im.mode != "1":
         msg = f"cannot write mode {im.mode} as XBM"
         raise OSError(msg)

src/PIL/_typing.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import os
 import sys
+from typing import Protocol, TypeVar
 
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
@@ -15,4 +17,16 @@ def __class_getitem__(cls, item: Any) -> type[bool]:
                 return bool
 
 
-__all__ = ["TypeGuard"]
+_T_co = TypeVar("_T_co", covariant=True)
+
+
+class SupportsRead(Protocol[_T_co]):
+    def read(self, __length: int = ...) -> _T_co:
+        ...
+
+
+FileDescriptor = int
+StrOrBytesPath = str | bytes | os.PathLike[str] | os.PathLike[bytes]
+
+
+__all__ = ["FileDescriptor", "TypeGuard", "StrOrBytesPath", "SupportsRead"]

src/PIL/_util.py

@@ -4,10 +4,10 @@
 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]:
+def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
     return isinstance(f, (bytes, str, Path))