Added type hints

Tests/test_file_png.py

@@ -41,7 +41,7 @@
 
 def chunk(cid: bytes, *data: bytes) -> bytes:
     test_file = BytesIO()
-    PngImagePlugin.putchunk(*(test_file, cid) + data)
+    PngImagePlugin.putchunk(test_file, cid, *data)
     return test_file.getvalue()
 
 

Tests/test_imagefile.py

@@ -127,7 +127,7 @@ def test_raise_oserror(self) -> None:
     def test_raise_typeerror(self) -> None:
         with pytest.raises(TypeError):
             parser = ImageFile.Parser()
-            parser.feed(1)
+            parser.feed(1)  # type: ignore[arg-type]
 
     def test_negative_stride(self) -> None:
         with open("Tests/images/raw_negative_stride.bin", "rb") as f:
@@ -305,7 +305,7 @@ def test_oversize(self) -> None:
             im.load()
 
     def test_decode(self) -> None:
-        decoder = ImageFile.PyDecoder(None)
+        decoder = ImageFile.PyDecoder("")
         with pytest.raises(NotImplementedError):
             decoder.decode(b"")
 
@@ -383,7 +383,7 @@ def test_oversize(self) -> None:
             )
 
     def test_encode(self) -> None:
-        encoder = ImageFile.PyEncoder(None)
+        encoder = ImageFile.PyEncoder("")
         with pytest.raises(NotImplementedError):
             encoder.encode(0)
 

src/PIL/ImageFile.py

@@ -86,7 +86,7 @@ def raise_oserror(error: int) -> OSError:
     raise _get_oserror(error, encoder=False)
 
 
-def _tilesort(t):
+def _tilesort(t) -> int:
     # sort on offset
     return t[2]
 
@@ -161,7 +161,7 @@ def get_format_mimetype(self) -> str | None:
             return Image.MIME.get(self.format.upper())
         return None
 
-    def __setstate__(self, state):
+    def __setstate__(self, state) -> None:
         self.tile = []
         super().__setstate__(state)
 
@@ -333,14 +333,14 @@ def load_end(self) -> None:
     # def load_read(self, read_bytes: int) -> bytes:
     #     pass
 
-    def _seek_check(self, frame):
+    def _seek_check(self, frame: int) -> bool:
         if (
             frame < self._min_frame
             # Only check upper limit on frames if additional seek operations
             # are not required to do so
             or (
                 not (hasattr(self, "_n_frames") and self._n_frames is None)
-                and frame >= self.n_frames + self._min_frame
+                and frame >= getattr(self, "n_frames") + self._min_frame
             )
         ):
             msg = "attempt to seek outside sequence"
@@ -370,15 +370,15 @@ def _open(self) -> None:
         msg = "StubImageFile subclass must implement _open"
         raise NotImplementedError(msg)
 
-    def load(self):
+    def load(self) -> Image.core.PixelAccess | None:
         loader = self._load()
         if loader is None:
             msg = f"cannot find loader for this {self.format} file"
             raise OSError(msg)
         image = loader.load(self)
         assert image is not None
         # become the other object (!)
-        self.__class__ = image.__class__
+        self.__class__ = image.__class__  # type: ignore[assignment]
         self.__dict__ = image.__dict__
         return image.load()
 
@@ -396,8 +396,8 @@ class Parser:
 
     incremental = None
     image: Image.Image | None = None
-    data = None
-    decoder = None
+    data: bytes | None = None
+    decoder: Image.core.ImagingDecoder | PyDecoder | None = None
     offset = 0
     finished = 0
 
@@ -409,7 +409,7 @@ def reset(self) -> None:
         """
         assert self.data is None, "cannot reuse parsers"
 
-    def feed(self, data):
+    def feed(self, data: bytes) -> None:
         """
         (Consumer) Feed data to the parser.
 
@@ -491,7 +491,7 @@ def __enter__(self) -> Parser:
     def __exit__(self, *args: object) -> None:
         self.close()
 
-    def close(self):
+    def close(self) -> Image.Image:
         """
         (Consumer) Close the stream.
 
@@ -525,7 +525,7 @@ def close(self):
 # --------------------------------------------------------------------
 
 
-def _save(im, fp, tile, bufsize=0) -> None:
+def _save(im, fp, tile, bufsize: int = 0) -> None:
     """Helper to save image based on tile list
 
     :param im: Image object.
@@ -553,7 +553,7 @@ def _save(im, fp, tile, bufsize=0) -> None:
         fp.flush()
 
 
-def _encode_tile(im, fp, tile: list[_Tile], bufsize, fh, exc=None):
+def _encode_tile(im, fp, tile: list[_Tile], bufsize: int, fh, exc=None) -> None:
     for encoder_name, extents, offset, args in tile:
         if offset > 0:
             fp.seek(offset)
@@ -629,18 +629,18 @@ def extents(self) -> tuple[int, int, int, int]:
 class PyCodec:
     fd: IO[bytes] | None
 
-    def __init__(self, mode, *args):
-        self.im = None
+    def __init__(self, mode: str, *args: Any) -> None:
+        self.im: Image.core.ImagingCore | None = None
         self.state = PyCodecState()
         self.fd = None
         self.mode = mode
         self.init(args)
 
-    def init(self, args) -> None:
+    def init(self, args: tuple[Any, ...]) -> None:
         """
         Override to perform codec specific initialization
 
-        :param args: Array of args items from the tile entry
+        :param args: Tuple of arg items from the tile entry
         :returns: None
         """
         self.args = args
@@ -662,7 +662,7 @@ def setfd(self, fd) -> None:
         """
         self.fd = fd
 
-    def setimage(self, im, extents: tuple[int, int, int, int] | None = None) -> None:
+    def setimage(self, im, extents=None):
         """
         Called from ImageFile to set the core output image for the codec
 

src/PIL/ImageSequence.py

@@ -33,7 +33,7 @@ class Iterator:
     :param im: An image object.
     """
 
-    def __init__(self, im: Image.Image):
+    def __init__(self, im: Image.Image) -> None:
         if not hasattr(im, "seek"):
             msg = "im must have seek method"
             raise AttributeError(msg)

src/PIL/JpegImagePlugin.py

@@ -827,11 +827,11 @@ def _save_cjpeg(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
 
 ##
 # Factory for making JPEG and MPO instances
-def jpeg_factory(fp=None, filename=None):
+def jpeg_factory(fp: IO[bytes] | None = None, filename: str | bytes | None = None):
     im = JpegImageFile(fp, filename)
     try:
         mpheader = im._getmp()
-        if mpheader[45057] > 1:
+        if mpheader is not None and mpheader[45057] > 1:
             for segment, content in im.applist:
                 if segment == "APP1" and b' hdrgm:Version="' in content:
                     # Ultra HDR images are not yet supported

src/PIL/PdfImagePlugin.py

@@ -174,12 +174,15 @@ def _write_image(im, filename, existing_pdf, image_refs):
     return image_ref, procset
 
 
-def _save(im, fp, filename, save_all=False):
+def _save(
+    im: Image.Image, fp: IO[bytes], filename: str | bytes, save_all: bool = False
+) -> None:
     is_appending = im.encoderinfo.get("append", False)
+    filename_str = filename.decode() if isinstance(filename, bytes) else filename
     if is_appending:
-        existing_pdf = PdfParser.PdfParser(f=fp, filename=filename, mode="r+b")
+        existing_pdf = PdfParser.PdfParser(f=fp, filename=filename_str, mode="r+b")
     else:
-        existing_pdf = PdfParser.PdfParser(f=fp, filename=filename, mode="w+b")
+        existing_pdf = PdfParser.PdfParser(f=fp, filename=filename_str, mode="w+b")
 
     dpi = im.encoderinfo.get("dpi")
     if dpi:
@@ -228,12 +231,7 @@ def _save(im, fp, filename, save_all=False):
     for im in ims:
         im_number_of_pages = 1
         if save_all:
-            try:
-                im_number_of_pages = im.n_frames
-            except AttributeError:
-                # Image format does not have n_frames.
-                # It is a single frame image
-                pass
+            im_number_of_pages = getattr(im, "n_frames", 1)
         number_of_pages += im_number_of_pages
         for i in range(im_number_of_pages):
             image_refs.append(existing_pdf.next_object_id(0))
@@ -250,7 +248,9 @@ def _save(im, fp, filename, save_all=False):
 
     page_number = 0
     for im_sequence in ims:
-        im_pages = ImageSequence.Iterator(im_sequence) if save_all else [im_sequence]
+        im_pages: ImageSequence.Iterator | list[Image.Image] = (
+            ImageSequence.Iterator(im_sequence) if save_all else [im_sequence]
+        )
         for im in im_pages:
             image_ref, procset = _write_image(im, filename, existing_pdf, image_refs)
 

src/PIL/PngImagePlugin.py

@@ -144,7 +144,7 @@ def _safe_zlib_decompress(s):
     return plaintext
 
 
-def _crc32(data, seed=0):
+def _crc32(data: bytes, seed: int = 0) -> int:
     return zlib.crc32(data, seed) & 0xFFFFFFFF
 
 
@@ -191,7 +191,7 @@ def push(self, cid: bytes, pos: int, length: int) -> None:
         assert self.queue is not None
         self.queue.append((cid, pos, length))
 
-    def call(self, cid, pos, length):
+    def call(self, cid: bytes, pos: int, length: int) -> bytes:
         """Call the appropriate chunk handler"""
 
         logger.debug("STREAM %r %s %s", cid, pos, length)
@@ -1091,21 +1091,21 @@ def getexif(self) -> Image.Exif:
 }
 
 
-def putchunk(fp, cid, *data):
+def putchunk(fp: IO[bytes], cid: bytes, *data: bytes) -> None:
     """Write a PNG chunk (including CRC field)"""
 
-    data = b"".join(data)
+    byte_data = b"".join(data)
 
-    fp.write(o32(len(data)) + cid)
-    fp.write(data)
-    crc = _crc32(data, _crc32(cid))
+    fp.write(o32(len(byte_data)) + cid)
+    fp.write(byte_data)
+    crc = _crc32(byte_data, _crc32(cid))
     fp.write(o32(crc))
 
 
 class _idat:
     # wrap output from the encoder in IDAT chunks
 
-    def __init__(self, fp, chunk):
+    def __init__(self, fp, chunk) -> None:
         self.fp = fp
         self.chunk = chunk
 
@@ -1116,7 +1116,7 @@ def write(self, data: bytes) -> None:
 class _fdat:
     # wrap encoder output in fdAT chunks
 
-    def __init__(self, fp, chunk, seq_num):
+    def __init__(self, fp: IO[bytes], chunk, seq_num: int) -> None:
         self.fp = fp
         self.chunk = chunk
         self.seq_num = seq_num
@@ -1259,7 +1259,9 @@ def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
     _save(im, fp, filename, save_all=True)
 
 
-def _save(im, fp, filename, chunk=putchunk, save_all=False):
+def _save(
+    im: Image.Image, fp, filename: str | bytes, chunk=putchunk, save_all: bool = False
+) -> None:
     # save an image to disk (called by the save method)
 
     if save_all:
@@ -1461,7 +1463,7 @@ def _save(im, fp, filename, chunk=putchunk, save_all=False):
 # PNG chunk converter
 
 
-def getchunks(im, **params):
+def getchunks(im: Image.Image, **params: Any) -> list[tuple[bytes, bytes, bytes]]:
     """Return a list of PNG chunks representing this image."""
 
     class collector:
@@ -1470,19 +1472,19 @@ class collector:
         def write(self, data: bytes) -> None:
             pass
 
-        def append(self, chunk: bytes) -> None:
+        def append(self, chunk: tuple[bytes, bytes, bytes]) -> None:
             self.data.append(chunk)
 
-    def append(fp, cid, *data):
-        data = b"".join(data)
-        crc = o32(_crc32(data, _crc32(cid)))
-        fp.append((cid, data, crc))
+    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))
 
     fp = collector()
 
     try:
         im.encoderinfo = params
-        _save(im, fp, None, append)
+        _save(im, fp, "", append)
     finally:
         del im.encoderinfo