Added type hints

docs/reference/ImageFile.rst

@@ -57,6 +57,10 @@ Classes
     :undoc-members:
     :show-inheritance:
 
+.. autoclass:: PIL.ImageFile.StubHandler()
+    :members:
+    :show-inheritance:
+
 .. autoclass:: PIL.ImageFile.StubImageFile()
     :members:
     :show-inheritance:

setup.py

@@ -215,7 +215,7 @@ def _add_directory(path, subdir, where=None):
         path.insert(where, subdir)
 
 
-def _find_include_file(self, include):
+def _find_include_file(self, include: str) -> int:
     for directory in self.compiler.include_dirs:
         _dbg("Checking for include file %s in %s", (include, directory))
         if os.path.isfile(os.path.join(directory, include)):
@@ -255,7 +255,7 @@ def _cmd_exists(cmd: str) -> bool:
     )
 
 
-def _pkg_config(name):
+def _pkg_config(name: str) -> tuple[str, str] | None:
     command = os.environ.get("PKG_CONFIG", "pkg-config")
     for keep_system in (True, False):
         try:
@@ -282,6 +282,7 @@ def _pkg_config(name):
             return libs, cflags
         except Exception:
             pass
+    return None
 
 
 class pil_build_ext(build_ext):

src/PIL/BlpImagePlugin.py

@@ -55,7 +55,7 @@ class AlphaEncoding(IntEnum):
     DXT5 = 7
 
 
-def unpack_565(i):
+def unpack_565(i: int) -> tuple[int, int, int]:
     return ((i >> 11) & 0x1F) << 3, ((i >> 5) & 0x3F) << 2, (i & 0x1F) << 3
 
 
@@ -284,7 +284,8 @@ def decode(self, buffer):
             raise OSError(msg) from e
         return -1, 0
 
-    def _read_blp_header(self):
+    def _read_blp_header(self) -> None:
+        assert self.fd is not None
         self.fd.seek(4)
         (self._blp_compression,) = struct.unpack("<i", self._safe_read(4))
 
@@ -303,10 +304,10 @@ def _read_blp_header(self):
         self._blp_offsets = struct.unpack("<16I", self._safe_read(16 * 4))
         self._blp_lengths = struct.unpack("<16I", self._safe_read(16 * 4))
 
-    def _safe_read(self, length):
+    def _safe_read(self, length: int) -> bytes:
         return ImageFile._safe_read(self.fd, length)
 
-    def _read_palette(self):
+    def _read_palette(self) -> list[tuple[int, int, int, int]]:
         ret = []
         for i in range(256):
             try:
@@ -349,29 +350,30 @@ def _load(self) -> None:
             msg = f"Unsupported BLP compression {repr(self._blp_encoding)}"
             raise BLPFormatError(msg)
 
-    def _decode_jpeg_stream(self):
+    def _decode_jpeg_stream(self) -> None:
         from .JpegImagePlugin import JpegImageFile
 
         (jpeg_header_size,) = struct.unpack("<I", self._safe_read(4))
         jpeg_header = self._safe_read(jpeg_header_size)
+        assert self.fd is not None
         self._safe_read(self._blp_offsets[0] - self.fd.tell())  # What IS this?
         data = self._safe_read(self._blp_lengths[0])
         data = jpeg_header + data
-        data = BytesIO(data)
-        image = JpegImageFile(data)
+        image = JpegImageFile(BytesIO(data))
         Image._decompression_bomb_check(image.size)
         if image.mode == "CMYK":
             decoder_name, extents, offset, args = image.tile[0]
             image.tile = [(decoder_name, extents, offset, (args[0], "CMYK"))]
         r, g, b = image.convert("RGB").split()
-        image = Image.merge("RGB", (b, g, r))
-        self.set_as_raw(image.tobytes())
+        reversed_image = Image.merge("RGB", (b, g, r))
+        self.set_as_raw(reversed_image.tobytes())
 
 
 class BLP2Decoder(_BLPBaseDecoder):
-    def _load(self):
+    def _load(self) -> None:
         palette = self._read_palette()
 
+        assert self.fd is not None
         self.fd.seek(self._blp_offsets[0])
 
         if self._blp_compression == 1:

src/PIL/BufrStubImagePlugin.py

@@ -15,7 +15,7 @@
 _handler = None
 
 
-def register_handler(handler):
+def register_handler(handler: ImageFile.StubHandler) -> None:
     """
     Install application-specific BUFR image handler.
 
@@ -54,7 +54,7 @@ def _open(self) -> None:
         if loader:
             loader.open(self)
 
-    def _load(self):
+    def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 

src/PIL/DcxImagePlugin.py

@@ -42,7 +42,7 @@ class DcxImageFile(PcxImageFile):
     format_description = "Intel DCX"
     _close_exclusive_fp_after_loading = False
 
-    def _open(self):
+    def _open(self) -> None:
         # Header
         s = self.fp.read(4)
         if not _accept(s):
@@ -58,7 +58,7 @@ def _open(self):
             self._offset.append(offset)
 
         self._fp = self.fp
-        self.frame = None
+        self.frame = -1
         self.n_frames = len(self._offset)
         self.is_animated = self.n_frames > 1
         self.seek(0)

src/PIL/GimpPaletteFile.py

@@ -16,6 +16,7 @@
 from __future__ import annotations
 
 import re
+from typing import IO
 
 from ._binary import o8
 
@@ -25,8 +26,8 @@ class GimpPaletteFile:
 
     rawmode = "RGB"
 
-    def __init__(self, fp):
-        self.palette = [o8(i) * 3 for i in range(256)]
+    def __init__(self, fp: IO[bytes]) -> None:
+        palette = [o8(i) * 3 for i in range(256)]
 
         if fp.readline()[:12] != b"GIMP Palette":
             msg = "not a GIMP palette file"
@@ -49,9 +50,9 @@ def __init__(self, fp):
                 msg = "bad palette entry"
                 raise ValueError(msg)
 
-            self.palette[i] = o8(v[0]) + o8(v[1]) + o8(v[2])
+            palette[i] = o8(v[0]) + o8(v[1]) + o8(v[2])
 
-        self.palette = b"".join(self.palette)
+        self.palette = b"".join(palette)
 
     def getpalette(self) -> tuple[bytes, str]:
         return self.palette, self.rawmode

src/PIL/GribStubImagePlugin.py

@@ -15,7 +15,7 @@
 _handler = None
 
 
-def register_handler(handler):
+def register_handler(handler: ImageFile.StubHandler) -> None:
     """
     Install application-specific GRIB image handler.
 
@@ -54,7 +54,7 @@ def _open(self) -> None:
         if loader:
             loader.open(self)
 
-    def _load(self):
+    def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 

src/PIL/Hdf5StubImagePlugin.py

@@ -10,12 +10,14 @@
 #
 from __future__ import annotations
 
+from typing import IO
+
 from . import Image, ImageFile
 
 _handler = None
 
 
-def register_handler(handler):
+def register_handler(handler: ImageFile.StubHandler) -> None:
     """
     Install application-specific HDF5 image handler.
 
@@ -54,11 +56,11 @@ def _open(self) -> None:
         if loader:
             loader.open(self)
 
-    def _load(self):
+    def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 
-def _save(im, fp, filename):
+def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
     if _handler is None or not hasattr(_handler, "save"):
         msg = "HDF5 save handler not installed"
         raise OSError(msg)

src/PIL/Image.py

@@ -1948,7 +1948,9 @@ def putalpha(self, alpha):
 
         self.im.putband(alpha.im, band)
 
-    def putdata(self, data, scale=1.0, offset=0.0):
+    def putdata(
+        self, data: Sequence[float], scale: float = 1.0, offset: float = 0.0
+    ) -> None:
         """
         Copies pixel data from a flattened sequence object into the image. The
         values should start at the upper left corner (0, 0), continue to the

src/PIL/ImageFile.py

@@ -28,6 +28,7 @@
 #
 from __future__ import annotations
 
+import abc
 import io
 import itertools
 import struct
@@ -347,6 +348,18 @@ def _seek_check(self, frame):
         return self.tell() != frame
 
 
+class StubHandler:
+    def open(self, im: StubImageFile) -> None:
+        pass
+
+    @abc.abstractmethod
+    def load(self, im: StubImageFile) -> Image.Image:
+        pass
+
+    def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
+        pass
+
+
 class StubImageFile(ImageFile):
     """
     Base class for stub image loaders.

src/PIL/ImageFilter.py

@@ -18,6 +18,7 @@
 
 import abc
 import functools
+from typing import Sequence
 
 
 class Filter:
@@ -79,7 +80,7 @@ class RankFilter(Filter):
 
     name = "Rank"
 
-    def __init__(self, size, rank):
+    def __init__(self, size: int, rank: int) -> None:
         self.size = size
         self.rank = rank
 
@@ -101,7 +102,7 @@ class MedianFilter(RankFilter):
 
     name = "Median"
 
-    def __init__(self, size=3):
+    def __init__(self, size: int = 3) -> None:
         self.size = size
         self.rank = size * size // 2
 
@@ -116,7 +117,7 @@ class MinFilter(RankFilter):
 
     name = "Min"
 
-    def __init__(self, size=3):
+    def __init__(self, size: int = 3) -> None:
         self.size = size
         self.rank = 0
 
@@ -131,7 +132,7 @@ class MaxFilter(RankFilter):
 
     name = "Max"
 
-    def __init__(self, size=3):
+    def __init__(self, size: int = 3) -> None:
         self.size = size
         self.rank = size * size - 1
 
@@ -147,7 +148,7 @@ class ModeFilter(Filter):
 
     name = "Mode"
 
-    def __init__(self, size=3):
+    def __init__(self, size: int = 3) -> None:
         self.size = size
 
     def filter(self, image):
@@ -165,7 +166,7 @@ class GaussianBlur(MultibandFilter):
 
     name = "GaussianBlur"
 
-    def __init__(self, radius=2):
+    def __init__(self, radius: float | Sequence[float] = 2) -> None:
         self.radius = radius
 
     def filter(self, image):
@@ -228,7 +229,9 @@ class UnsharpMask(MultibandFilter):
 
     name = "UnsharpMask"
 
-    def __init__(self, radius=2, percent=150, threshold=3):
+    def __init__(
+        self, radius: float = 2, percent: int = 150, threshold: int = 3
+    ) -> None:
         self.radius = radius
         self.percent = percent
         self.threshold = threshold

src/PIL/ImageFont.py

@@ -254,14 +254,14 @@ def __setstate__(self, state):
         path, size, index, encoding, layout_engine = state
         self.__init__(path, size, index, encoding, layout_engine)
 
-    def getname(self):
+    def getname(self) -> tuple[str, str]:
         """
         :return: A tuple of the font family (e.g. Helvetica) and the font style
             (e.g. Bold)
         """
         return self.font.family, self.font.style
 
-    def getmetrics(self):
+    def getmetrics(self) -> tuple[int, int]:
         """
         :return: A tuple of the font ascent (the distance from the baseline to
             the highest outline point) and descent (the distance from the
@@ -628,7 +628,7 @@ def font_variant(
             layout_engine=layout_engine or self.layout_engine,
         )
 
-    def get_variation_names(self):
+    def get_variation_names(self) -> list[bytes]:
         """
         :returns: A list of the named styles in a variation font.
         :exception OSError: If the font is not a variation font.