mypy strict mode

Tests/test_file_jpeg.py

@@ -19,6 +19,7 @@
     UnidentifiedImageError,
     features,
 )
+from PIL._typing import Buffer
 
 from .helper import (
     assert_image,
@@ -40,6 +41,7 @@
 except ImportError:
     ElementTree = None
 
+
 TEST_FILE = "Tests/images/hopper.jpg"
 
 
@@ -1064,7 +1066,7 @@ def test_eof(self, monkeypatch: pytest.MonkeyPatch) -> None:
         # the image should still end when there is no new data
         class InfiniteMockPyDecoder(ImageFile.PyDecoder):
             def decode(
-                self, buffer: bytes | Image.SupportsArrayInterface
+                self, buffer: Buffer | Image.SupportsArrayInterface
             ) -> tuple[int, int]:
                 return 0, 0
 

Tests/test_file_jpeg2k.py

@@ -165,7 +165,7 @@ def test_reduce() -> None:
         assert callable(im.reduce)
 
         im.reduce = 2  # type: ignore[assignment, method-assign]
-        assert im.reduce == 2
+        assert im.reduce == 2  # type: ignore[comparison-overlap]
 
         im.load()
         assert im.size == (160, 120)

Tests/test_image_frombytes.py

@@ -11,7 +11,7 @@
 def test_sanity(data_type: str) -> None:
     im1 = hopper()
 
-    data = im1.tobytes()
+    data: bytes | memoryview[int] = im1.tobytes()
     if data_type == "memoryview":
         data = memoryview(data)
     im2 = Image.frombytes(im1.mode, im1.size, data)

Tests/test_imagefile.py

@@ -14,6 +14,7 @@
     _binary,
     features,
 )
+from PIL._typing import Buffer
 
 from .helper import (
     assert_image,
@@ -238,7 +239,7 @@ def __init__(self, mode: str, *args: Any) -> None:
 
         super().__init__(mode, *args)
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         # eof
         return -1, 0
 

Tests/test_imagewin.py

@@ -116,7 +116,7 @@ def test_dib_frombytes_tobytes_roundtrip(self) -> None:
 
         # Act
         # Make one the same as the using tobytes()/frombytes()
-        test_buffer = dib1.tobytes()
+        test_buffer: bytes | memoryview[int] = dib1.tobytes()
         for datatype in ("bytes", "memoryview"):
             if datatype == "memoryview":
                 test_buffer = memoryview(test_buffer)

Tests/test_qt_image_toqimage.py

@@ -10,13 +10,15 @@
 if TYPE_CHECKING:
     from pathlib import Path
 
+    QImage = type
+else:
+    if ImageQt.qt_is_installed:
+        from PIL.ImageQt import QImage
+
 pytestmark = pytest.mark.skipif(
     not ImageQt.qt_is_installed, reason="Qt bindings are not installed"
 )
 
-if ImageQt.qt_is_installed:
-    from PIL.ImageQt import QImage
-
 
 @pytest.mark.parametrize("mode", ("RGB", "RGBA", "L", "P", "1"))
 def test_sanity(mode: str, tmp_path: Path) -> None:

docs/example/DdsImagePlugin.py

@@ -14,10 +14,16 @@
 
 import struct
 from io import BytesIO
-from typing import IO
 
 from PIL import Image, ImageFile
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from typing import IO
+
+    from typing_extensions import Buffer
+
+
 # Magic ("DDS ")
 DDS_MAGIC = 0x20534444
 
@@ -258,7 +264,7 @@ def load_seek(self, pos: int) -> None:
 class DXT1Decoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         assert self.fd is not None
         try:
             self.set_as_raw(_dxt1(self.fd, self.state.xsize, self.state.ysize))
@@ -271,7 +277,7 @@ def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int
 class DXT5Decoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         assert self.fd is not None
         try:
             self.set_as_raw(_dxt5(self.fd, self.state.xsize, self.state.ysize))

pyproject.toml

@@ -216,11 +216,10 @@ testpaths = [
 [tool.mypy]
 python_version = "3.10"
 pretty = true
-disallow_any_generics = true
-disallow_untyped_defs = true
+strict = true
+disallow_subclassing_any = false
+disallow_untyped_calls = false
 enable_error_code = "ignore-without-code"
-extra_checks = true
-follow_imports = "silent"
-warn_redundant_casts = true
+no_implicit_reexport = false
+warn_return_any = false
 warn_unreachable = true
-warn_unused_ignores = true

src/PIL/BlpImagePlugin.py

@@ -39,6 +39,7 @@
 from typing import IO
 
 from . import Image, ImageFile
+from ._typing import Buffer
 
 
 class Format(IntEnum):
@@ -295,7 +296,7 @@ def _open(self) -> None:
 class _BLPBaseDecoder(abc.ABC, ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         try:
             self._read_header()
             self._load()

src/PIL/BmpImagePlugin.py

@@ -33,6 +33,7 @@
 from ._binary import o8
 from ._binary import o16le as o16
 from ._binary import o32le as o32
+from ._typing import Buffer
 
 #
 # --------------------------------------------------------------------
@@ -327,7 +328,7 @@ def _open(self) -> None:
 class BmpRleDecoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         assert self.fd is not None
         rle4 = self.args[1]
         data = bytearray()

src/PIL/DdsImagePlugin.py

@@ -21,6 +21,7 @@
 from ._binary import i32le as i32
 from ._binary import o8
 from ._binary import o32le as o32
+from ._typing import Buffer
 
 # Magic ("DDS ")
 DDS_MAGIC = 0x20534444
@@ -488,7 +489,7 @@ def load_seek(self, pos: int) -> None:
 class DdsRgbDecoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         assert self.fd is not None
         bitcount, masks = self.args
 

src/PIL/EpsImagePlugin.py

@@ -203,7 +203,9 @@ def _open(self) -> None:
         imagedata_size: tuple[int, int] | None = None
 
         byte_arr = bytearray(255)
-        bytes_mv = memoryview(byte_arr)
+        # the extra `bytes` annotation here works around several false positive
+        # `comparison-overlap` mypy errors
+        bytes_mv: bytes | memoryview = memoryview(byte_arr)
         bytes_read = 0
         reading_header_comments = True
         reading_trailer_comments = False

src/PIL/FitsImagePlugin.py

@@ -14,6 +14,7 @@
 import math
 
 from . import Image, ImageFile
+from ._typing import Buffer
 
 
 def _accept(prefix: bytes) -> bool:
@@ -126,7 +127,7 @@ def _parse_headers(
 class FitsGzipDecoder(ImageFile.PyDecoder):
     _pulls_fd = True
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         assert self.fd is not None
         value = gzip.decompress(self.fd.read())
 

src/PIL/GifImagePlugin.py

@@ -52,7 +52,6 @@
     from typing import IO, Literal
 
     from . import _imaging
-    from ._typing import Buffer
 
 
 class LoadingStrategy(IntEnum):
@@ -1188,7 +1187,7 @@ def getdata(
     class Collector(BytesIO):
         data = []
 
-        def write(self, data: Buffer) -> int:
+        def write(self, data: bytes) -> int:  # type: ignore[override]
             self.data.append(data)
             return len(data)
 

src/PIL/Image.py

@@ -69,6 +69,8 @@
     from types import ModuleType
     from typing import Any, Literal
 
+    from ._typing import Buffer
+
 logger = logging.getLogger(__name__)
 
 
@@ -86,37 +88,45 @@ class DecompressionBombError(Exception):
 MAX_IMAGE_PIXELS: int | None = int(1024 * 1024 * 1024 // 4 // 3)
 
 
-try:
-    # If the _imaging C module is not present, Pillow will not load.
-    # Note that other modules should not refer to _imaging directly;
-    # import Image and use the Image.core variable instead.
-    # Also note that Image.core is not a publicly documented interface,
-    # and should be considered private and subject to change.
-    from . import _imaging as core
-
-    if __version__ != getattr(core, "PILLOW_VERSION", None):
-        msg = (
-            "The _imaging extension was built for another version of Pillow or PIL:\n"
-            f"Core version: {getattr(core, 'PILLOW_VERSION', None)}\n"
-            f"Pillow version: {__version__}"
-        )
-        raise ImportError(msg)
+if TYPE_CHECKING:
+    from . import _imaging
 
-except ImportError as v:
-    # Explanations for ways that we know we might have an import error
-    if str(v).startswith("Module use of python"):
-        # The _imaging C module is present, but not compiled for
-        # the right version (windows only).  Print a warning, if
-        # possible.
-        warnings.warn(
-            "The _imaging extension was built for another version of Python.",
-            RuntimeWarning,
-        )
-    elif str(v).startswith("The _imaging extension"):
-        warnings.warn(str(v), RuntimeWarning)
-    # Fail here anyway. Don't let people run with a mostly broken Pillow.
-    # see docs/porting.rst
-    raise
+    # mypy will not recognize `core` as a public symbol when imported as
+    # `from . import _imaging as core`
+    core = _imaging
+else:
+    try:
+        # If the _imaging C module is not present, Pillow will not load.
+        # Note that other modules should not refer to _imaging directly;
+        # import Image and use the Image.core variable instead.
+        # Also note that Image.core is not a publicly documented interface,
+        # and should be considered private and subject to change.
+        from . import _imaging as core
+
+        if __version__ != getattr(core, "PILLOW_VERSION", None):
+            msg = (
+                f"The _imaging extension was built for another version of Pillow or "
+                f"PIL:\n "
+                f"Core version: {getattr(core, 'PILLOW_VERSION', None)}\n"
+                f"Pillow version: {__version__}"
+            )
+            raise ImportError(msg)
+
+    except ImportError as v:
+        # Explanations for ways that we know we might have an import error
+        if str(v).startswith("Module use of python"):
+            # The _imaging C module is present, but not compiled for
+            # the right version (windows only).  Print a warning, if
+            # possible.
+            warnings.warn(
+                "The _imaging extension was built for another version of Python.",
+                RuntimeWarning,
+            )
+        elif str(v).startswith("The _imaging extension"):
+            warnings.warn(str(v), RuntimeWarning)
+        # Fail here anyway. Don't let people run with a mostly broken Pillow.
+        # see docs/porting.rst
+        raise
 
 
 #
@@ -931,7 +941,7 @@ def tobitmap(self, name: str = "image") -> bytes:
 
     def frombytes(
         self,
-        data: bytes | bytearray | SupportsArrayInterface,
+        data: Buffer | SupportsArrayInterface,
         decoder_name: str = "raw",
         *args: Any,
     ) -> None:
@@ -3232,7 +3242,7 @@ def new(
 def frombytes(
     mode: str,
     size: tuple[int, int],
-    data: bytes | bytearray | SupportsArrayInterface,
+    data: Buffer | SupportsArrayInterface,
     decoder_name: str = "raw",
     *args: Any,
 ) -> Image:

src/PIL/ImageFile.py

@@ -41,7 +41,7 @@
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
-    from ._typing import StrOrBytesPath
+    from ._typing import Buffer, StrOrBytesPath
 
 logger = logging.getLogger(__name__)
 
@@ -839,7 +839,7 @@ class PyDecoder(PyCodec):
     def pulls_fd(self) -> bool:
         return self._pulls_fd
 
-    def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
+    def decode(self, buffer: Buffer | Image.SupportsArrayInterface) -> tuple[int, int]:
         """
         Override to perform the decoding process.
 
@@ -852,7 +852,10 @@ def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int
         raise NotImplementedError(msg)
 
     def set_as_raw(
-        self, data: bytes, rawmode: str | None = None, extra: tuple[Any, ...] = ()
+        self,
+        data: bytes | bytearray,
+        rawmode: str | None = None,
+        extra: tuple[Any, ...] = (),
     ) -> None:
         """
         Convenience method to set the internal image from a stream of raw data
@@ -893,7 +896,7 @@ class PyEncoder(PyCodec):
     def pushes_fd(self) -> bool:
         return self._pushes_fd
 
-    def encode(self, bufsize: int) -> tuple[int, int, bytes]:
+    def encode(self, bufsize: int) -> tuple[int, int, bytes | bytearray]:
         """
         Override to perform the encoding process.
 

src/PIL/ImageWin.py

@@ -19,6 +19,7 @@
 from __future__ import annotations
 
 from . import Image
+from ._typing import Buffer
 
 
 class HDC:
@@ -183,7 +184,7 @@ def paste(
         else:
             self.image.paste(im.im)
 
-    def frombytes(self, buffer: bytes) -> None:
+    def frombytes(self, buffer: Buffer) -> None:
         """
         Load display memory contents from byte data.