Added type hints

pyproject.toml

@@ -141,16 +141,6 @@ warn_redundant_casts = true
 warn_unreachable = true
 warn_unused_ignores = true
 exclude = [
-  '^src/PIL/_tkinter_finder.py$',
-  '^src/PIL/DdsImagePlugin.py$',
   '^src/PIL/FpxImagePlugin.py$',
-  '^src/PIL/Image.py$',
-  '^src/PIL/ImageQt.py$',
-  '^src/PIL/ImImagePlugin.py$',
   '^src/PIL/MicImagePlugin.py$',
-  '^src/PIL/PdfParser.py$',
-  '^src/PIL/PyAccess.py$',
-  '^src/PIL/TiffImagePlugin.py$',
-  '^src/PIL/TiffTags.py$',
-  '^src/PIL/WebPImagePlugin.py$',
 ]

src/PIL/DdsImagePlugin.py

@@ -270,13 +270,17 @@ class D3DFMT(IntEnum):
 # Backward compatibility layer
 module = sys.modules[__name__]
 for item in DDSD:
+    assert item.name is not None
     setattr(module, "DDSD_" + item.name, item.value)
-for item in DDSCAPS:
-    setattr(module, "DDSCAPS_" + item.name, item.value)
-for item in DDSCAPS2:
-    setattr(module, "DDSCAPS2_" + item.name, item.value)
-for item in DDPF:
-    setattr(module, "DDPF_" + item.name, item.value)
+for item1 in DDSCAPS:
+    assert item1.name is not None
+    setattr(module, "DDSCAPS_" + item1.name, item1.value)
+for item2 in DDSCAPS2:
+    assert item2.name is not None
+    setattr(module, "DDSCAPS2_" + item2.name, item2.value)
+for item3 in DDPF:
+    assert item3.name is not None
+    setattr(module, "DDPF_" + item3.name, item3.value)
 
 DDS_FOURCC = DDPF.FOURCC
 DDS_RGB = DDPF.RGB

src/PIL/ImImagePlugin.py

@@ -93,8 +93,8 @@ for i in ["16", "16L", "16B"]:
 for i in ["32S"]:
     OPEN[f"L {i} image"] = ("I", f"I;{i}")
     OPEN[f"L*{i} image"] = ("I", f"I;{i}")
-for i in range(2, 33):
-    OPEN[f"L*{i} image"] = ("F", f"F;{i}")
+for j in range(2, 33):
+    OPEN[f"L*{j} image"] = ("F", f"F;{j}")
 
 
 # --------------------------------------------------------------------

src/PIL/Image.py

@@ -26,6 +26,7 @@
 
 from __future__ import annotations
 
+import abc
 import atexit
 import builtins
 import io
@@ -40,11 +41,8 @@ import warnings
 from collections.abc import Callable, MutableMapping
 from enum import IntEnum
 from pathlib import Path
-
-try:
-    from defusedxml import ElementTree
-except ImportError:
-    ElementTree = None
+from types import ModuleType
+from typing import IO, TYPE_CHECKING, Any
 
 # VERSION was removed in Pillow 6.0.0.
 # PILLOW_VERSION was removed in Pillow 9.0.0.
@@ -60,6 +58,12 @@ from . import (
 from ._binary import i32le, o32be, o32le
 from ._util import DeferredError, is_path
 
+ElementTree: ModuleType | None
+try:
+    from defusedxml import ElementTree
+except ImportError:
+    ElementTree = None
+
 logger = logging.getLogger(__name__)
 
 
@@ -110,6 +114,7 @@ except ImportError as v:
 
 
 USE_CFFI_ACCESS = False
+cffi: ModuleType | None
 try:
     import cffi
 except ImportError:
@@ -211,14 +216,22 @@ if hasattr(core, "DEFAULT_STRATEGY"):
 # --------------------------------------------------------------------
 # Registries
 
-ID = []
-OPEN = {}
-MIME = {}
-SAVE = {}
-SAVE_ALL = {}
-EXTENSION = {}
-DECODERS = {}
-ENCODERS = {}
+if TYPE_CHECKING:
+    from . import ImageFile  # pragma: no cover
+ID: list[str] = []
+OPEN: dict[
+    str,
+    tuple[
+        Callable[[IO[bytes], str | bytes], ImageFile.ImageFile],
+        Callable[[bytes], bool] | None,
+    ],
+] = {}
+MIME: dict[str, str] = {}
+SAVE: dict[str, Callable[[Image, IO[bytes], str | bytes], None]] = {}
+SAVE_ALL: dict[str, Callable[[Image, IO[bytes], str | bytes], None]] = {}
+EXTENSION: dict[str, str] = {}
+DECODERS: dict[str, object] = {}
+ENCODERS: dict[str, object] = {}
 
 # --------------------------------------------------------------------
 # Modes
@@ -2383,12 +2396,12 @@ class Image:
            may have been created, and may contain partial data.
         """
 
-        filename = ""
+        filename: str | bytes = ""
         open_fp = False
         if isinstance(fp, Path):
             filename = str(fp)
             open_fp = True
-        elif is_path(fp):
+        elif isinstance(fp, (str, bytes)):
             filename = fp
             open_fp = True
         elif fp == sys.stdout:
@@ -2398,7 +2411,7 @@ class Image:
                 pass
         if not filename and hasattr(fp, "name") and is_path(fp.name):
             # only set the name for metadata purposes
-            filename = fp.name
+            filename = os.path.realpath(os.fspath(fp.name))
 
         # may mutate self!
         self._ensure_mutable()
@@ -2409,7 +2422,8 @@ class Image:
 
         preinit()
 
-        ext = os.path.splitext(filename)[1].lower()
+        filename_ext = os.path.splitext(filename)[1].lower()
+        ext = filename_ext.decode() if isinstance(filename_ext, bytes) else filename_ext
 
         if not format:
             if ext not in EXTENSION:
@@ -2451,7 +2465,7 @@ class Image:
         if open_fp:
             fp.close()
 
-    def seek(self, frame) -> Image:
+    def seek(self, frame) -> None:
         """
         Seeks to the given frame in this sequence file. If you seek
         beyond the end of the sequence, the method raises an
@@ -2511,10 +2525,9 @@ class Image:
 
         self.load()
         if self.im.bands == 1:
-            ims = [self.copy()]
+            return (self.copy(),)
         else:
-            ims = map(self._new, self.im.split())
-        return tuple(ims)
+            return tuple(map(self._new, self.im.split()))
 
     def getchannel(self, channel):
         """
@@ -2871,7 +2884,14 @@ class ImageTransformHandler:
     (for use with :py:meth:`~PIL.Image.Image.transform`)
     """
 
-    pass
+    @abc.abstractmethod
+    def transform(
+        self,
+        size: tuple[int, int],
+        image: Image,
+        **options: dict[str, str | int | tuple[int, ...] | list[int]],
+    ) -> Image:
+        pass  # pragma: no cover
 
 
 # --------------------------------------------------------------------
@@ -3243,11 +3263,9 @@ def open(fp, mode="r", formats=None) -> Image:
         raise TypeError(msg)
 
     exclusive_fp = False
-    filename = ""
-    if isinstance(fp, Path):
-        filename = str(fp.resolve())
-    elif is_path(fp):
-        filename = fp
+    filename: str | bytes = ""
+    if is_path(fp):
+        filename = os.path.realpath(os.fspath(fp))
 
     if filename:
         fp = builtins.open(filename, "rb")
@@ -3421,7 +3439,11 @@ def merge(mode, bands):
 # Plugin registry
 
 
-def register_open(id, factory, accept=None) -> None:
+def register_open(
+    id,
+    factory: Callable[[IO[bytes], str | bytes], ImageFile.ImageFile],
+    accept: Callable[[bytes], bool] | None = None,
+) -> None:
     """
     Register an image file plugin.  This function should not be used
     in application code.
@@ -3631,7 +3653,13 @@ _apply_env_variables()
 atexit.register(core.clear_cache)
 
 
-class Exif(MutableMapping):
+if TYPE_CHECKING:
+    _ExifBase = MutableMapping[int, Any]  # pragma: no cover
+else:
+    _ExifBase = MutableMapping
+
+
+class Exif(_ExifBase):
     """
     This class provides read and write access to EXIF image data::
 

src/PIL/ImageQt.py

@@ -19,19 +19,26 @@ from __future__ import annotations
 
 import sys
 from io import BytesIO
+from typing import Callable
 
 from . import Image
 from ._util import is_path
 
+qt_version: str | None
 qt_versions = [
     ["6", "PyQt6"],
     ["side6", "PySide6"],
 ]
 
 # If a version has already been imported, attempt it first
-qt_versions.sort(key=lambda qt_version: qt_version[1] in sys.modules, reverse=True)
-for qt_version, qt_module in qt_versions:
+qt_versions.sort(key=lambda version: version[1] in sys.modules, reverse=True)
+for version, qt_module in qt_versions:
     try:
+        QBuffer: type
+        QIODevice: type
+        QImage: type
+        QPixmap: type
+        qRgba: Callable[[int, int, int, int], int]
         if qt_module == "PyQt6":
             from PyQt6.QtCore import QBuffer, QIODevice
             from PyQt6.QtGui import QImage, QPixmap, qRgba
@@ -41,6 +48,7 @@ for qt_version, qt_module in qt_versions:
     except (ImportError, RuntimeError):
         continue
     qt_is_installed = True
+    qt_version = version
     break
 else:
     qt_is_installed = False

src/PIL/PdfParser.py

@@ -8,6 +8,7 @@ import os
 import re
 import time
 import zlib
+from typing import TYPE_CHECKING, Any, List, Union
 
 
 # see 7.9.2.2 Text String Type on page 86 and D.3 PDFDocEncoding Character Set
@@ -239,12 +240,18 @@ class PdfName:
         return bytes(result)
 
 
-class PdfArray(list):
+class PdfArray(List[Any]):
     def __bytes__(self):
         return b"[ " + b" ".join(pdf_repr(x) for x in self) + b" ]"
 
 
-class PdfDict(collections.UserDict):
+if TYPE_CHECKING:
+    _DictBase = collections.UserDict[Union[str, bytes], Any]  # pragma: no cover
+else:
+    _DictBase = collections.UserDict
+
+
+class PdfDict(_DictBase):
     def __setattr__(self, key, value):
         if key == "data":
             collections.UserDict.__setattr__(self, key, value)

src/PIL/PyAccess.py

@@ -25,6 +25,7 @@ import sys
 
 from ._deprecate import deprecate
 
+FFI: type
 try:
     from cffi import FFI
 

src/PIL/TiffImagePlugin.py

@@ -50,6 +50,7 @@ import warnings
 from collections.abc import MutableMapping
 from fractions import Fraction
 from numbers import Number, Rational
+from typing import TYPE_CHECKING, Any, Callable
 
 from . import ExifTags, Image, ImageFile, ImageOps, ImagePalette, TiffTags
 from ._binary import i16be as i16
@@ -306,6 +307,13 @@ _load_dispatch = {}
 _write_dispatch = {}
 
 
+def _delegate(op):
+    def delegate(self, *args):
+        return getattr(self._val, op)(*args)
+
+    return delegate
+
+
 class IFDRational(Rational):
     """Implements a rational class where 0/0 is a legal value to match
     the in the wild use of exif rationals.
@@ -391,12 +399,6 @@ class IFDRational(Rational):
         self._numerator = _numerator
         self._denominator = _denominator
 
-    def _delegate(op):
-        def delegate(self, *args):
-            return getattr(self._val, op)(*args)
-
-        return delegate
-
     """ a = ['add','radd', 'sub', 'rsub', 'mul', 'rmul',
              'truediv', 'rtruediv', 'floordiv', 'rfloordiv',
              'mod','rmod', 'pow','rpow', 'pos', 'neg',
@@ -436,7 +438,50 @@ class IFDRational(Rational):
         __int__ = _delegate("__int__")
 
 
-class ImageFileDirectory_v2(MutableMapping):
+def _register_loader(idx, size):
+    def decorator(func):
+        from .TiffTags import TYPES
+
+        if func.__name__.startswith("load_"):
+            TYPES[idx] = func.__name__[5:].replace("_", " ")
+        _load_dispatch[idx] = size, func  # noqa: F821
+        return func
+
+    return decorator
+
+
+def _register_writer(idx):
+    def decorator(func):
+        _write_dispatch[idx] = func  # noqa: F821
+        return func
+
+    return decorator
+
+
+def _register_basic(idx_fmt_name):
+    from .TiffTags import TYPES
+
+    idx, fmt, name = idx_fmt_name
+    TYPES[idx] = name
+    size = struct.calcsize("=" + fmt)
+    _load_dispatch[idx] = (  # noqa: F821
+        size,
+        lambda self, data, legacy_api=True: (
+            self._unpack(f"{len(data) // size}{fmt}", data)
+        ),
+    )
+    _write_dispatch[idx] = lambda self, *values: (  # noqa: F821
+        b"".join(self._pack(fmt, value) for value in values)
+    )
+
+
+if TYPE_CHECKING:
+    _IFDv2Base = MutableMapping[int, Any]  # pragma: no cover
+else:
+    _IFDv2Base = MutableMapping
+
+
+class ImageFileDirectory_v2(_IFDv2Base):
     """This class represents a TIFF tag directory.  To speed things up, we
     don't decode tags unless they're asked for.
 
@@ -497,6 +542,9 @@ class ImageFileDirectory_v2(MutableMapping):
 
     """
 
+    _load_dispatch: dict[int, Callable[[ImageFileDirectory_v2, bytes, bool], Any]] = {}
+    _write_dispatch: dict[int, Callable[..., Any]] = {}
+
     def __init__(self, ifh=b"II\052\0\0\0\0\0", prefix=None, group=None):
         """Initialize an ImageFileDirectory.
 
@@ -531,7 +579,10 @@ class ImageFileDirectory_v2(MutableMapping):
 
     prefix = property(lambda self: self._prefix)
     offset = property(lambda self: self._offset)
-    legacy_api = property(lambda self: self._legacy_api)
+
+    @property
+    def legacy_api(self):
+        return self._legacy_api
 
     @legacy_api.setter
     def legacy_api(self, value):
@@ -674,40 +725,6 @@ class ImageFileDirectory_v2(MutableMapping):
     def _pack(self, fmt, *values):
         return struct.pack(self._endian + fmt, *values)
 
-    def _register_loader(idx, size):
-        def decorator(func):
-            from .TiffTags import TYPES
-
-            if func.__name__.startswith("load_"):
-                TYPES[idx] = func.__name__[5:].replace("_", " ")
-            _load_dispatch[idx] = size, func  # noqa: F821
-            return func
-
-        return decorator
-
-    def _register_writer(idx):
-        def decorator(func):
-            _write_dispatch[idx] = func  # noqa: F821
-            return func
-
-        return decorator
-
-    def _register_basic(idx_fmt_name):
-        from .TiffTags import TYPES
-
-        idx, fmt, name = idx_fmt_name
-        TYPES[idx] = name
-        size = struct.calcsize("=" + fmt)
-        _load_dispatch[idx] = (  # noqa: F821
-            size,
-            lambda self, data, legacy_api=True: (
-                self._unpack(f"{len(data) // size}{fmt}", data)
-            ),
-        )
-        _write_dispatch[idx] = lambda self, *values: (  # noqa: F821
-            b"".join(self._pack(fmt, value) for value in values)
-        )
-
     list(
         map(
             _register_basic,
@@ -995,7 +1012,7 @@ class ImageFileDirectory_v1(ImageFileDirectory_v2):
     tagdata = property(lambda self: self._tagdata)
 
     # defined in ImageFileDirectory_v2
-    tagtype: dict
+    tagtype: dict[int, int]
     """Dictionary of tag types"""
 
     @classmethod
@@ -1835,11 +1852,11 @@ def _save(im, fp, filename):
         tags = list(atts.items())
         tags.sort()
         a = (rawmode, compression, _fp, filename, tags, types)
-        e = Image._getencoder(im.mode, "libtiff", a, encoderconfig)
-        e.setimage(im.im, (0, 0) + im.size)
+        encoder = Image._getencoder(im.mode, "libtiff", a, encoderconfig)
+        encoder.setimage(im.im, (0, 0) + im.size)
         while True:
             # undone, change to self.decodermaxblock:
-            errcode, data = e.encode(16 * 1024)[1:]
+            errcode, data = encoder.encode(16 * 1024)[1:]
             if not _fp:
                 fp.write(data)
             if errcode:

src/PIL/TiffTags.py

@@ -22,7 +22,7 @@ from collections import namedtuple
 
 
 class TagInfo(namedtuple("_TagInfo", "value name type length enum")):
-    __slots__ = []
+    __slots__: list[str] = []
 
     def __new__(cls, value=None, name="unknown", type=None, length=None, enum=None):
         return super().__new__(cls, value, name, type, length, enum or {})
@@ -437,7 +437,7 @@ _populate()
 ##
 # Map type numbers to type names -- defined in ImageFileDirectory.
 
-TYPES = {}
+TYPES: dict[int, str] = {}
 
 #
 # These tags are handled by default in libtiff, without

src/PIL/_imaging.pyi

@@ -0,0 +1,5 @@
+from __future__ import annotations
+
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

src/PIL/_tkinter_finder.py

@@ -5,7 +5,8 @@ from __future__ import annotations
 
 import sys
 import tkinter
-from tkinter import _tkinter as tk
+
+tk = getattr(tkinter, "_tkinter")
 
 try:
     if hasattr(sys, "pypy_find_executable"):

src/PIL/_webp.pyi

@@ -0,0 +1,5 @@
+from __future__ import annotations
+
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

tox.ini

@@ -33,9 +33,14 @@ commands =
 [testenv:mypy]
 skip_install = true
 deps =
+    IceSpringPySideStubs-PyQt6
+    IceSpringPySideStubs-PySide6
     ipython
     mypy==1.7.1
     numpy
+    packaging
+    types-cffi
+    types-defusedxml
 extras =
     typing
 commands =