Added type hints

Tests/test_file_png.py

@@ -424,8 +424,10 @@ class TestFilePng:
         im = roundtrip(im, pnginfo=info)
         assert im.info == {"spam": "Eggs", "eggs": "Spam"}
         assert im.text == {"spam": "Eggs", "eggs": "Spam"}
+        assert isinstance(im.text["spam"], PngImagePlugin.iTXt)
         assert im.text["spam"].lang == "en"
         assert im.text["spam"].tkey == "Spam"
+        assert isinstance(im.text["eggs"], PngImagePlugin.iTXt)
         assert im.text["eggs"].lang == "en"
         assert im.text["eggs"].tkey == "Eggs"
 

src/PIL/Image.py

@@ -38,7 +38,7 @@ import struct
 import sys
 import tempfile
 import warnings
-from collections.abc import Callable, MutableMapping, Sequence
+from collections.abc import Callable, Iterator, MutableMapping, Sequence
 from enum import IntEnum
 from types import ModuleType
 from typing import (
@@ -744,11 +744,11 @@ class Image:
         new["shape"], new["typestr"] = _conv_type_shape(self)
         return new
 
-    def __getstate__(self):
+    def __getstate__(self) -> list[Any]:
         im_data = self.tobytes()  # load image first
         return [self.info, self.mode, self.size, self.getpalette(), im_data]
 
-    def __setstate__(self, state) -> None:
+    def __setstate__(self, state: list[Any]) -> None:
         Image.__init__(self)
         info, mode, size, palette, data = state
         self.info = info
@@ -1683,7 +1683,9 @@ class Image:
         x, y = self.im.getprojection()
         return list(x), list(y)
 
-    def histogram(self, mask: Image | None = None, extrema=None) -> list[int]:
+    def histogram(
+        self, mask: Image | None = None, extrema: tuple[float, float] | None = None
+    ) -> list[int]:
         """
         Returns a histogram for the image. The histogram is returned as a
         list of pixel counts, one for each pixel value in the source
@@ -1709,12 +1711,14 @@ class Image:
             mask.load()
             return self.im.histogram((0, 0), mask.im)
         if self.mode in ("I", "F"):
-            if extrema is None:
+            return self.im.histogram(
-                extrema = self.getextrema()
+                extrema if extrema is not None else self.getextrema()
-            return self.im.histogram(extrema)
+            )
         return self.im.histogram()
 
-    def entropy(self, mask: Image | None = None, extrema=None):
+    def entropy(
+        self, mask: Image | None = None, extrema: tuple[float, float] | None = None
+    ) -> float:
         """
         Calculates and returns the entropy for the image.
 
@@ -1735,9 +1739,9 @@ class Image:
             mask.load()
             return self.im.entropy((0, 0), mask.im)
         if self.mode in ("I", "F"):
-            if extrema is None:
+            return self.im.entropy(
-                extrema = self.getextrema()
+                extrema if extrema is not None else self.getextrema()
-            return self.im.entropy(extrema)
+            )
         return self.im.entropy()
 
     def paste(
@@ -3881,7 +3885,7 @@ class Exif(_ExifBase):
         # returns a dict with any single item tuples/lists as individual values
         return {k: self._fixup(v) for k, v in src_dict.items()}
 
-    def _get_ifd_dict(self, offset: int, group=None):
+    def _get_ifd_dict(self, offset: int, group: int | None = None):
         try:
             # an offset pointer to the location of the nested embedded IFD.
             # It should be a long, but may be corrupted.
@@ -4136,7 +4140,7 @@ class Exif(_ExifBase):
         else:
             del self._data[tag]
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[int]:
         keys = set(self._data)
         if self._info is not None:
             keys.update(self._info)

src/PIL/ImageDraw2.py

@@ -24,7 +24,7 @@
 """
 from __future__ import annotations
 
-from typing import AnyStr, BinaryIO
+from typing import Any, AnyStr, BinaryIO
 
 from . import Image, ImageColor, ImageDraw, ImageFont, ImagePath
 from ._typing import Coords, StrOrBytesPath
@@ -111,7 +111,7 @@ class Draw:
         (xoffset, yoffset) = offset
         self.transform = (1, 0, xoffset, 0, 1, yoffset)
 
-    def arc(self, xy: Coords, start, end, *options) -> None:
+    def arc(self, xy: Coords, start, end, *options: Any) -> None:
         """
         Draws an arc (a portion of a circle outline) between the start and end
         angles, inside the given bounding box.
@@ -120,7 +120,7 @@ class Draw:
         """
         self.render("arc", xy, start, end, *options)
 
-    def chord(self, xy: Coords, start, end, *options) -> None:
+    def chord(self, xy: Coords, start, end, *options: Any) -> None:
         """
         Same as :py:meth:`~PIL.ImageDraw2.Draw.arc`, but connects the end points
         with a straight line.
@@ -129,7 +129,7 @@ class Draw:
         """
         self.render("chord", xy, start, end, *options)
 
-    def ellipse(self, xy: Coords, *options) -> None:
+    def ellipse(self, xy: Coords, *options: Any) -> None:
         """
         Draws an ellipse inside the given bounding box.
 
@@ -137,7 +137,7 @@ class Draw:
         """
         self.render("ellipse", xy, *options)
 
-    def line(self, xy: Coords, *options) -> None:
+    def line(self, xy: Coords, *options: Any) -> None:
         """
         Draws a line between the coordinates in the ``xy`` list.
 
@@ -145,7 +145,7 @@ class Draw:
         """
         self.render("line", xy, *options)
 
-    def pieslice(self, xy: Coords, start, end, *options) -> None:
+    def pieslice(self, xy: Coords, start, end, *options: Any) -> None:
         """
         Same as arc, but also draws straight lines between the end points and the
         center of the bounding box.
@@ -154,7 +154,7 @@ class Draw:
         """
         self.render("pieslice", xy, start, end, *options)
 
-    def polygon(self, xy: Coords, *options) -> None:
+    def polygon(self, xy: Coords, *options: Any) -> None:
         """
         Draws a polygon.
 

src/PIL/PngImagePlugin.py

@@ -38,6 +38,7 @@ import re
 import struct
 import warnings
 import zlib
+from collections.abc import Callable
 from enum import IntEnum
 from typing import IO, TYPE_CHECKING, Any, NamedTuple, NoReturn
 
@@ -135,7 +136,7 @@ class Blend(IntEnum):
     """
 
 
-def _safe_zlib_decompress(s):
+def _safe_zlib_decompress(s: bytes) -> bytes:
     dobj = zlib.decompressobj()
     plaintext = dobj.decompress(s, MAX_TEXT_CHUNK)
     if dobj.unconsumed_tail:
@@ -783,7 +784,7 @@ class PngImageFile(ImageFile.ImageFile):
         self._mode = self.png.im_mode
         self._size = self.png.im_size
         self.info = self.png.im_info
-        self._text = None
+        self._text: dict[str, str | iTXt] | None = None
         self.tile = self.png.im_tile
         self.custom_mimetype = self.png.im_custom_mimetype
         self.n_frames = self.png.im_n_frames or 1
@@ -810,7 +811,7 @@ class PngImageFile(ImageFile.ImageFile):
         self.is_animated = self.n_frames > 1
 
     @property
-    def text(self):
+    def text(self) -> dict[str, str | iTXt]:
         # experimental
         if self._text is None:
             # iTxt, tEXt and zTXt chunks may appear at the end of the file
@@ -822,6 +823,7 @@ class PngImageFile(ImageFile.ImageFile):
             self.load()
             if self.is_animated:
                 self.seek(frame)
+        assert self._text is not None
         return self._text
 
     def verify(self) -> None:
@@ -1105,7 +1107,7 @@ def putchunk(fp: IO[bytes], cid: bytes, *data: bytes) -> None:
 class _idat:
     # wrap output from the encoder in IDAT chunks
 
-    def __init__(self, fp, chunk) -> None:
+    def __init__(self, fp: IO[bytes], chunk: Callable[..., None]) -> None:
         self.fp = fp
         self.chunk = chunk
 
@@ -1116,7 +1118,7 @@ class _idat:
 class _fdat:
     # wrap encoder output in fdAT chunks
 
-    def __init__(self, fp: IO[bytes], chunk, seq_num: int) -> None:
+    def __init__(self, fp: IO[bytes], chunk: Callable[..., None], seq_num: int) -> None:
         self.fp = fp
         self.chunk = chunk
         self.seq_num = seq_num
@@ -1135,7 +1137,7 @@ class _Frame(NamedTuple):
 def _write_multiple_frames(
     im: Image.Image,
     fp: IO[bytes],
-    chunk,
+    chunk: Callable[..., None],
     mode: str,
     rawmode: str,
     default_image: Image.Image | None,
@@ -1275,7 +1277,11 @@ def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
 
 
 def _save(
-    im: Image.Image, fp, filename: str | bytes, chunk=putchunk, save_all: bool = False
+    im: Image.Image,
+    fp: IO[bytes],
+    filename: str | bytes,
+    chunk: Callable[..., None] = putchunk,
+    save_all: bool = False,
 ) -> None:
     # save an image to disk (called by the save method)
 
@@ -1483,22 +1489,16 @@ def _save(
 
 def getchunks(im: Image.Image, **params: Any) -> list[tuple[bytes, bytes, bytes]]:
     """Return a list of PNG chunks representing this image."""
+    from io import BytesIO
 
-    class collector:
+    chunks = []
-        data = []
 
-        def write(self, data: bytes) -> None:
+    def append(fp: IO[bytes], cid: bytes, *data: bytes) -> None:
-            pass
-
-        def append(self, chunk: tuple[bytes, bytes, bytes]) -> None:
-            self.data.append(chunk)
-
-    def append(fp: collector, cid: bytes, *data: bytes) -> None:
         byte_data = b"".join(data)
         crc = o32(_crc32(byte_data, _crc32(cid)))
-        fp.append((cid, byte_data, crc))
+        chunks.append((cid, byte_data, crc))
 
-    fp = collector()
+    fp = BytesIO()
 
     try:
         im.encoderinfo = params
@@ -1506,7 +1506,7 @@ def getchunks(im: Image.Image, **params: Any) -> list[tuple[bytes, bytes, bytes]
     finally:
         del im.encoderinfo
 
-    return fp.data
+    return chunks
 
 
 # --------------------------------------------------------------------

src/PIL/TiffImagePlugin.py

@@ -1020,7 +1020,7 @@ class ImageFileDirectory_v1(ImageFileDirectory_v2):
     ..  deprecated:: 3.0.0
     """
 
-    def __init__(self, *args, **kwargs) -> None:
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         self._legacy_api = True
 
@@ -1142,13 +1142,15 @@ class TiffImageFile(ImageFile.ImageFile):
         self._seek(0)
 
     @property
-    def n_frames(self):
+    def n_frames(self) -> int:
-        if self._n_frames is None:
+        current_n_frames = self._n_frames
+        if current_n_frames is None:
             current = self.tell()
             self._seek(len(self._frame_pos))
             while self._n_frames is None:
                 self._seek(self.tell() + 1)
             self.seek(current)
+        assert self._n_frames is not None
         return self._n_frames
 
     def seek(self, frame: int) -> None: