Added type hints

src/PIL/BlpImagePlugin.py

@@ -31,6 +31,7 @@
 
 from __future__ import annotations
 
+import abc
 import os
 import struct
 from enum import IntEnum
@@ -276,7 +277,7 @@ def _open(self) -> None:
 class _BLPBaseDecoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer):
+    def decode(self, buffer: bytes) -> tuple[int, int]:
         try:
             self._read_blp_header()
             self._load()
@@ -285,6 +286,10 @@ def decode(self, buffer):
             raise OSError(msg) from e
         return -1, 0
 
+    @abc.abstractmethod
+    def _load(self) -> None:
+        pass
+
     def _read_blp_header(self) -> None:
         assert self.fd is not None
         self.fd.seek(4)
@@ -318,7 +323,7 @@ def _read_palette(self) -> list[tuple[int, int, int, int]]:
             ret.append((b, g, r, a))
         return ret
 
-    def _read_bgra(self, palette):
+    def _read_bgra(self, palette: list[tuple[int, int, int, int]]) -> bytearray:
         data = bytearray()
         _data = BytesIO(self._safe_read(self._blp_lengths[0]))
         while True:
@@ -327,7 +332,7 @@ def _read_bgra(self, palette):
             except struct.error:
                 break
             b, g, r, a = palette[offset]
-            d = (r, g, b)
+            d: tuple[int, ...] = (r, g, b)
             if self._blp_alpha_depth:
                 d += (a,)
             data.extend(d)
@@ -431,7 +436,7 @@ def _write_palette(self) -> bytes:
             data += b"\x00" * 4
         return data
 
-    def encode(self, bufsize):
+    def encode(self, bufsize: int) -> tuple[int, int, bytes]:
         palette_data = self._write_palette()
 
         offset = 20 + 16 * 4 * 2 + len(palette_data)
@@ -449,7 +454,7 @@ def encode(self, bufsize):
         return len(data), 0, data
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if im.mode != "P":
         msg = "Unsupported BLP image mode"
         raise ValueError(msg)

src/PIL/BmpImagePlugin.py

@@ -395,12 +395,12 @@ def _open(self) -> None:
 }
 
 
-def _dib_save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _dib_save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     _save(im, fp, filename, False)
 
 
 def _save(
-    im: Image.Image, fp: IO[bytes], filename: str, bitmap_header: bool = True
+    im: Image.Image, fp: IO[bytes], filename: str | bytes, bitmap_header: bool = True
 ) -> None:
     try:
         rawmode, bits, colors = SAVE[im.mode]

src/PIL/BufrStubImagePlugin.py

@@ -60,7 +60,7 @@ def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if _handler is None or not hasattr(_handler, "save"):
         msg = "BUFR save handler not installed"
         raise OSError(msg)

src/PIL/DdsImagePlugin.py

@@ -511,7 +511,7 @@ def decode(self, buffer):
         return -1, 0
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if im.mode not in ("RGB", "RGBA", "L", "LA"):
         msg = f"cannot write mode {im.mode} as DDS"
         raise OSError(msg)

src/PIL/GifImagePlugin.py

@@ -715,12 +715,12 @@ def _write_multiple_frames(im, fp, palette):
     return True
 
 
-def _save_all(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     _save(im, fp, filename, save_all=True)
 
 
 def _save(
-    im: Image.Image, fp: IO[bytes], filename: str, save_all: bool = False
+    im: Image.Image, fp: IO[bytes], filename: str | bytes, save_all: bool = False
 ) -> None:
     # header
     if "palette" in im.encoderinfo or "palette" in im.info:
@@ -796,7 +796,7 @@ def _write_local_header(fp, im, offset, flags):
     fp.write(o8(8))  # bits
 
 
-def _save_netpbm(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save_netpbm(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     # Unused by default.
     # To use, uncomment the register_save call at the end of the file.
     #

src/PIL/GribStubImagePlugin.py

@@ -60,7 +60,7 @@ def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if _handler is None or not hasattr(_handler, "save"):
         msg = "GRIB save handler not installed"
         raise OSError(msg)

src/PIL/Hdf5StubImagePlugin.py

@@ -60,7 +60,7 @@ def _load(self) -> ImageFile.StubHandler | None:
         return _handler
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if _handler is None or not hasattr(_handler, "save"):
         msg = "HDF5 save handler not installed"
         raise OSError(msg)

src/PIL/IcnsImagePlugin.py

@@ -22,6 +22,7 @@
 import os
 import struct
 import sys
+from typing import IO
 
 from . import Image, ImageFile, PngImagePlugin, features
 
@@ -312,7 +313,7 @@ def load(self):
         return px
 
 
-def _save(im, fp, filename):
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     """
     Saves the image as a series of PNG files,
     that are then combined into a .icns file.
@@ -346,29 +347,27 @@ def _save(im, fp, filename):
     entries = []
     for type, size in sizes.items():
         stream = size_streams[size]
-        entries.append(
-            {"type": type, "size": HEADERSIZE + len(stream), "stream": stream}
-        )
+        entries.append((type, HEADERSIZE + len(stream), stream))
 
     # Header
     fp.write(MAGIC)
     file_length = HEADERSIZE  # Header
     file_length += HEADERSIZE + 8 * len(entries)  # TOC
-    file_length += sum(entry["size"] for entry in entries)
+    file_length += sum(entry[1] for entry in entries)
     fp.write(struct.pack(">i", file_length))
 
     # TOC
     fp.write(b"TOC ")
     fp.write(struct.pack(">i", HEADERSIZE + len(entries) * HEADERSIZE))
     for entry in entries:
-        fp.write(entry["type"])
-        fp.write(struct.pack(">i", entry["size"]))
+        fp.write(entry[0])
+        fp.write(struct.pack(">i", entry[1]))
 
     # Data
     for entry in entries:
-        fp.write(entry["type"])
-        fp.write(struct.pack(">i", entry["size"]))
-        fp.write(entry["stream"])
+        fp.write(entry[0])
+        fp.write(struct.pack(">i", entry[1]))
+        fp.write(entry[2])
 
     if hasattr(fp, "flush"):
         fp.flush()

src/PIL/IcoImagePlugin.py

@@ -40,7 +40,7 @@
 _MAGIC = b"\0\0\1\0"
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     fp.write(_MAGIC)  # (2+2)
     bmp = im.encoderinfo.get("bitmap_format") == "bmp"
     sizes = im.encoderinfo.get(

src/PIL/ImImagePlugin.py

@@ -326,7 +326,7 @@
 }
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     try:
         image_type, rawmode = SAVE[im.mode]
     except KeyError as e:
@@ -341,6 +341,8 @@
         # or: SyntaxError("not an IM file")
         # 8 characters are used for "Name: " and "\r\n"
         # Keep just the filename, ditch the potentially overlong path
+        if isinstance(filename, bytes):
+            filename = filename.decode("ascii")
         name, ext = os.path.splitext(os.path.basename(filename))
         name = "".join([name[: 92 - len(ext)], ext])
 

src/PIL/Image.py

@@ -626,7 +626,7 @@ def _ensure_mutable(self) -> None:
             self.load()
 
     def _dump(
-        self, file: str | None = None, format: str | None = None, **options
+        self, file: str | None = None, format: str | None = None, **options: Any
     ) -> str:
         suffix = ""
         if format:
@@ -649,10 +649,12 @@ def _dump(
 
         return filename
 
-    def __eq__(self, other):
+    def __eq__(self, other: object) -> bool:
+        if self.__class__ is not other.__class__:
+            return False
+        assert isinstance(other, Image)
         return (
-            self.__class__ is other.__class__
-            and self.mode == other.mode
+            self.mode == other.mode
             and self.size == other.size
             and self.info == other.info
             and self.getpalette() == other.getpalette()
@@ -2965,7 +2967,7 @@ def transform(
 # Debugging
 
 
-def _wedge():
+def _wedge() -> Image:
     """Create grayscale wedge (for debugging only)"""
 
     return Image()._new(core.wedge("L"))
@@ -3566,7 +3568,9 @@ def register_mime(id: str, mimetype: str) -> None:
     MIME[id.upper()] = mimetype
 
 
-def register_save(id: str, driver) -> None:
+def register_save(
+    id: str, driver: Callable[[Image, IO[bytes], str | bytes], None]
+) -> None:
     """
     Registers an image save function.  This function should not be
     used in application code.
@@ -3577,7 +3581,9 @@ def register_save(id: str, driver) -> None:
     SAVE[id.upper()] = driver
 
 
-def register_save_all(id: str, driver) -> None:
+def register_save_all(
+    id: str, driver: Callable[[Image, IO[bytes], str | bytes], None]
+) -> None:
     """
     Registers an image function to save all the frames
     of a multiframe format.  This function should not be
@@ -3651,7 +3657,7 @@ def register_encoder(name: str, encoder: type[ImageFile.PyEncoder]) -> None:
 # Simple display support.
 
 
-def _show(image, **options) -> None:
+def _show(image: Image, **options: Any) -> None:
     from . import ImageShow
 
     ImageShow.show(image, **options)
@@ -3661,7 +3667,9 @@ def _show(image, **options) -> None:
 # Effects
 
 
-def effect_mandelbrot(size, extent, quality):
+def effect_mandelbrot(
+    size: tuple[int, int], extent: tuple[int, int, int, int], quality: int
+) -> Image:
     """
     Generate a Mandelbrot set covering the given extent.
 

src/PIL/ImageDraw.py

@@ -219,7 +219,9 @@ def line(self, xy: Coords, fill=None, width=0, joint=None) -> None:
                         # This is a straight line, so no joint is required
                         continue
 
-                    def coord_at_angle(coord, angle):
+                    def coord_at_angle(
+                        coord: Sequence[float], angle: float
+                    ) -> tuple[float, float]:
                         x, y = coord
                         angle -= 90
                         distance = width / 2 - 1
@@ -1109,11 +1111,13 @@ def _get_angles(n_sides: int, rotation: float) -> list[float]:
     return [_compute_polygon_vertex(angle) for angle in angles]
 
 
-def _color_diff(color1, color2: float | tuple[int, ...]) -> float:
+def _color_diff(
+    color1: float | tuple[int, ...], color2: float | tuple[int, ...]
+) -> float:
     """
     Uses 1-norm distance to calculate difference between two values.
     """
-    if isinstance(color2, tuple):
-        return sum(abs(color1[i] - color2[i]) for i in range(0, len(color2)))
-    else:
-        return abs(color1 - color2)
+    first = color1 if isinstance(color1, tuple) else (color1,)
+    second = color2 if isinstance(color2, tuple) else (color2,)
+
+    return sum(abs(first[i] - second[i]) for i in range(0, len(second)))

src/PIL/ImageFile.py

@@ -763,7 +763,7 @@ class PyEncoder(PyCodec):
     def pushes_fd(self):
         return self._pushes_fd
 
-    def encode(self, bufsize):
+    def encode(self, bufsize: int) -> tuple[int, int, bytes]:
         """
         Override to perform the encoding process.
 

src/PIL/Jpeg2KImagePlugin.py

@@ -329,11 +329,13 @@ def _accept(prefix: bytes) -> bool:
 # Save support
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     # Get the keyword arguments
     info = im.encoderinfo
 
-    if filename.endswith(".j2k") or info.get("no_jp2", False):
+    if isinstance(filename, str):
+        filename = filename.encode()
+    if filename.endswith(b".j2k") or info.get("no_jp2", False):
         kind = "j2k"
     else:
         kind = "jp2"

src/PIL/JpegImagePlugin.py

@@ -42,7 +42,7 @@
 import sys
 import tempfile
 import warnings
-from typing import Any
+from typing import IO, Any
 
 from . import Image, ImageFile
 from ._binary import i16be as i16
@@ -644,7 +644,7 @@ def get_sampling(im):
     return samplings.get(sampling, -1)
 
 
-def _save(im, fp, filename):
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if im.width == 0 or im.height == 0:
         msg = "cannot write empty image as JPEG"
         raise ValueError(msg)
@@ -827,7 +827,7 @@ def validate_qtables(qtables):
     ImageFile._save(im, fp, [("jpeg", (0, 0) + im.size, 0, rawmode)], bufsize)
 
 
-def _save_cjpeg(im, fp, filename):
+def _save_cjpeg(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     # ALTERNATIVE: handle JPEGs via the IJG command line utilities.
     tempfile = im._dump()
     subprocess.check_call(["cjpeg", "-outfile", filename, tempfile])

src/PIL/MpoImagePlugin.py

@@ -33,7 +33,7 @@
 from ._binary import o32le
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     JpegImagePlugin._save(im, fp, filename)
 
 

src/PIL/MspImagePlugin.py

@@ -164,7 +164,7 @@ def decode(self, buffer: bytes) -> tuple[int, int]:
 # write MSP files (uncompressed only)
 
 
-def _save(im: Image.Image, fp: IO[bytes], filename: str) -> None:
+def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     if im.mode != "1":
         msg = f"cannot write mode {im.mode} as MSP"
         raise OSError(msg)