Added type hints

.ci/requirements-mypy.txt

@@ -6,6 +6,7 @@ numpy
 packaging
 pytest
 sphinx
+types-atheris
 types-defusedxml
 types-olefile
 types-setuptools

Tests/oss-fuzz/fuzz_font.py

@@ -16,8 +16,9 @@
 
 
 import atheris
+from atheris.import_hook import instrument_imports
 
-with atheris.instrument_imports():
+with instrument_imports():
     import sys
 
     import fuzzers

Tests/oss-fuzz/fuzz_pillow.py

@@ -14,8 +14,9 @@
 
 
 import atheris
+from atheris.import_hook import instrument_imports
 
-with atheris.instrument_imports():
+with instrument_imports():
     import sys
 
     import fuzzers

docs/reference/internal_modules.rst

@@ -33,6 +33,10 @@ Internal Modules
 Provides a convenient way to import type hints that are not available
 on some Python versions.
 
+.. py:class:: IntegralLike
+
+    Typing alias.
+
 .. py:class:: NumpyArray
 
     Typing alias.

pyproject.toml

@@ -163,7 +163,3 @@ follow_imports = "silent"
 warn_redundant_casts = true
 warn_unreachable = true
 warn_unused_ignores = true
-exclude = [
-  '^Tests/oss-fuzz/fuzz_font.py$',
-  '^Tests/oss-fuzz/fuzz_pillow.py$',
-]

src/PIL/BmpImagePlugin.py

@@ -387,7 +387,7 @@ class BmpRleDecoder(ImageFile.PyDecoder):
                     if self.fd.tell() % 2 != 0:
                         self.fd.seek(1, os.SEEK_CUR)
         rawmode = "L" if self.mode == "L" else "P"
-        self.set_as_raw(bytes(data), (rawmode, 0, self.args[-1]))
+        self.set_as_raw(bytes(data), rawmode, (0, self.args[-1]))
         return -1, 0
 
 

src/PIL/Image.py

@@ -225,6 +225,11 @@ if TYPE_CHECKING:
 
     from . import ImageFile, ImageFilter, ImagePalette, ImageQt, TiffImagePlugin
     from ._typing import NumpyArray, StrOrBytesPath, TypeGuard
+
+    if sys.version_info >= (3, 13):
+        from types import CapsuleType
+    else:
+        CapsuleType = object
 ID: list[str] = []
 OPEN: dict[
     str,
@@ -1598,7 +1603,7 @@ class Image:
             self.fp.seek(offset)
         return child_images
 
-    def getim(self):
+    def getim(self) -> CapsuleType:
         """
         Returns a capsule that points to the internal image memory.
 

src/PIL/ImageFile.py

@@ -736,19 +736,22 @@ class PyDecoder(PyCodec):
         msg = "unavailable in base decoder"
         raise NotImplementedError(msg)
 
-    def set_as_raw(self, data: bytes, rawmode=None) -> None:
+    def set_as_raw(
+        self, data: bytes, rawmode: str | None = None, extra: tuple[Any, ...] = ()
+    ) -> None:
         """
         Convenience method to set the internal image from a stream of raw data
 
         :param data: Bytes to be set
         :param rawmode: The rawmode to be used for the decoder.
             If not specified, it will default to the mode of the image
+        :param extra: Extra arguments for the decoder.
         :returns: None
         """
 
         if not rawmode:
             rawmode = self.mode
-        d = Image._getdecoder(self.mode, "raw", rawmode)
+        d = Image._getdecoder(self.mode, "raw", rawmode, extra)
         assert self.im is not None
         d.setimage(self.im, self.state.extents())
         s = d.decode(data)

src/PIL/ImageFont.py

@@ -34,7 +34,7 @@ import warnings
 from enum import IntEnum
 from io import BytesIO
 from types import ModuleType
-from typing import IO, TYPE_CHECKING, Any, BinaryIO, TypedDict
+from typing import IO, TYPE_CHECKING, Any, BinaryIO, TypedDict, cast
 
 from . import Image
 from ._typing import StrOrBytesPath
@@ -245,7 +245,7 @@ class FreeTypeFont:
 
         self.layout_engine = layout_engine
 
-        def load_from_bytes(f) -> None:
+        def load_from_bytes(f: IO[bytes]) -> None:
             self.font_bytes = f.read()
             self.font = core.getfont(
                 "", size, index, encoding, self.font_bytes, layout_engine
@@ -267,7 +267,7 @@ class FreeTypeFont:
                 font, size, index, encoding, layout_engine=layout_engine
             )
         else:
-            load_from_bytes(font)
+            load_from_bytes(cast(IO[bytes], font))
 
     def __getstate__(self) -> list[Any]:
         return [self.path, self.size, self.index, self.encoding, self.layout_engine]

src/PIL/Jpeg2KImagePlugin.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 import io
 import os
 import struct
+from collections.abc import Callable
 from typing import IO, cast
 
 from . import Image, ImageFile, ImagePalette, _binary
@@ -316,8 +317,13 @@ class Jpeg2KImageFile(ImageFile.ImageFile):
             else:
                 self.fp.seek(length - 2, os.SEEK_CUR)
 
-    @property
+    @property  # type: ignore[override]
-    def reduce(self):
+    def reduce(
+        self,
+    ) -> (
+        Callable[[int | tuple[int, int], tuple[int, int, int, int] | None], Image.Image]
+        | int
+    ):
         # https://github.com/python-pillow/Pillow/issues/4343 found that the
         # new Image 'reduce' method was shadowed by this plugin's 'reduce'
         # property. This attempts to allow for both scenarios

src/PIL/MspImagePlugin.py

@@ -152,7 +152,7 @@ class MspDecoder(ImageFile.PyDecoder):
                 msg = f"Corrupted MSP file in row {x}"
                 raise OSError(msg) from e
 
-        self.set_as_raw(img.getvalue(), ("1", 0, 1))
+        self.set_as_raw(img.getvalue(), "1")
 
         return -1, 0
 

src/PIL/PngImagePlugin.py

@@ -258,7 +258,9 @@ class iTXt(str):
     tkey: str | bytes | None
 
     @staticmethod
-    def __new__(cls, text, lang=None, tkey=None):
+    def __new__(
+        cls, text: str, lang: str | None = None, tkey: str | None = None
+    ) -> iTXt:
         """
         :param cls: the class to use when creating the instance
         :param text: value for this key

src/PIL/TiffImagePlugin.py

@@ -61,6 +61,9 @@ from ._typing import StrOrBytesPath
 from ._util import is_path
 from .TiffTags import TYPES
 
+if TYPE_CHECKING:
+    from ._typing import IntegralLike
+
 logger = logging.getLogger(__name__)
 
 # Set these to true to force use of libtiff for reading or writing.
@@ -291,22 +294,24 @@ def _accept(prefix: bytes) -> bool:
 
 def _limit_rational(
     val: float | Fraction | IFDRational, max_val: int
-) -> tuple[float, float]:
+) -> tuple[IntegralLike, IntegralLike]:
     inv = abs(float(val)) > 1
     n_d = IFDRational(1 / val if inv else val).limit_rational(max_val)
     return n_d[::-1] if inv else n_d
 
 
-def _limit_signed_rational(val, max_val, min_val):
+def _limit_signed_rational(
+    val: IFDRational, max_val: int, min_val: int
+) -> tuple[IntegralLike, IntegralLike]:
     frac = Fraction(val)
-    n_d = frac.numerator, frac.denominator
+    n_d: tuple[IntegralLike, IntegralLike] = frac.numerator, frac.denominator
 
-    if min(n_d) < min_val:
+    if min(float(i) for i in n_d) < min_val:
         n_d = _limit_rational(val, abs(min_val))
 
-    if max(n_d) > max_val:
+    n_d_float = tuple(float(i) for i in n_d)
-        val = Fraction(*n_d)
+    if max(n_d_float) > max_val:
-        n_d = _limit_rational(val, max_val)
+        n_d = _limit_rational(n_d_float[0] / n_d_float[1], max_val)
 
     return n_d
 
@@ -318,8 +323,10 @@ _load_dispatch = {}
 _write_dispatch = {}
 
 
-def _delegate(op: str):
+def _delegate(op: str) -> Any:
-    def delegate(self, *args):
+    def delegate(
+        self: IFDRational, *args: tuple[float, ...]
+    ) -> bool | float | Fraction:
         return getattr(self._val, op)(*args)
 
     return delegate
@@ -358,7 +365,10 @@ class IFDRational(Rational):
             self._numerator = value.numerator
             self._denominator = value.denominator
         else:
-            self._numerator = value
+            if TYPE_CHECKING:
+                self._numerator = cast(IntegralLike, value)
+            else:
+                self._numerator = value
             self._denominator = denominator
 
         if denominator == 0:
@@ -371,14 +381,14 @@ class IFDRational(Rational):
             self._val = Fraction(value / denominator)
 
     @property
-    def numerator(self):
+    def numerator(self) -> IntegralLike:
         return self._numerator
 
     @property
     def denominator(self) -> int:
         return self._denominator
 
-    def limit_rational(self, max_denominator: int) -> tuple[float, int]:
+    def limit_rational(self, max_denominator: int) -> tuple[IntegralLike, int]:
         """
 
         :param max_denominator: Integer, the maximum denominator value
@@ -406,14 +416,18 @@ class IFDRational(Rational):
             val = float(val)
         return val == other
 
-    def __getstate__(self) -> list[float | Fraction]:
+    def __getstate__(self) -> list[float | Fraction | IntegralLike]:
         return [self._val, self._numerator, self._denominator]
 
-    def __setstate__(self, state: list[float | Fraction]) -> None:
+    def __setstate__(self, state: list[float | Fraction | IntegralLike]) -> None:
         IFDRational.__init__(self, 0)
         _val, _numerator, _denominator = state
+        assert isinstance(_val, (float, Fraction))
         self._val = _val
-        self._numerator = _numerator
+        if TYPE_CHECKING:
+            self._numerator = cast(IntegralLike, _numerator)
+        else:
+            self._numerator = _numerator
         assert isinstance(_denominator, int)
         self._denominator = _denominator
 
@@ -471,8 +485,8 @@ def _register_loader(idx: int, size: int) -> Callable[[_LoaderFunc], _LoaderFunc
     return decorator
 
 
-def _register_writer(idx: int):
+def _register_writer(idx: int) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
-    def decorator(func):
+    def decorator(func: Callable[..., Any]) -> Callable[..., Any]:
         _write_dispatch[idx] = func  # noqa: F821
         return func
 

src/PIL/_typing.py

@@ -6,6 +6,8 @@ from collections.abc import Sequence
 from typing import TYPE_CHECKING, Any, Protocol, TypeVar, Union
 
 if TYPE_CHECKING:
+    from numbers import _IntegralLike as IntegralLike
+
     try:
         import numpy.typing as npt
 
@@ -38,4 +40,4 @@ class SupportsRead(Protocol[_T_co]):
 StrOrBytesPath = Union[str, bytes, "os.PathLike[str]", "os.PathLike[bytes]"]
 
 
-__all__ = ["TypeGuard", "StrOrBytesPath", "SupportsRead"]
+__all__ = ["IntegralLike", "StrOrBytesPath", "SupportsRead", "TypeGuard"]