Added type hints

pyproject.toml

@@ -147,7 +147,6 @@ exclude = [
   '^src/PIL/FpxImagePlugin.py$',
   '^src/PIL/Image.py$',
   '^src/PIL/ImageQt.py$',
-  '^src/PIL/ImageShow.py$',
   '^src/PIL/ImImagePlugin.py$',
   '^src/PIL/MicImagePlugin.py$',
   '^src/PIL/PdfParser.py$',

src/PIL/Image.py

@@ -242,7 +242,7 @@ MODES = ["1", "CMYK", "F", "HSV", "I", "L", "LAB", "P", "RGB", "RGBA", "RGBX", "
 _MAPMODES = ("L", "P", "RGBX", "RGBA", "CMYK", "I;16", "I;16L", "I;16B")
 
 
-def getmodebase(mode):
+def getmodebase(mode: str) -> str:
     """
     Gets the "base" mode for given mode.  This function returns "L" for
     images that contain grayscale data, and "RGB" for images that
@@ -583,7 +583,9 @@ class Image:
         else:
             self.load()
 
-    def _dump(self, file=None, format=None, **options):
+    def _dump(
+        self, file: str | None = None, format: str | None = None, **options
+    ) -> str:
         suffix = ""
         if format:
             suffix = "." + format

src/PIL/ImageShow.py

@@ -13,18 +13,20 @@
 #
 from __future__ import annotations
 
+import abc
 import os
 import shutil
 import subprocess
 import sys
 from shlex import quote
+from typing import Any
 
 from . import Image
 
 _viewers = []
 
 
-def register(viewer, order=1):
+def register(viewer, order: int = 1) -> None:
     """
     The :py:func:`register` function is used to register additional viewers::
 
@@ -49,7 +51,7 @@ def register(viewer, order=1):
         _viewers.insert(0, viewer)
 
 
-def show(image, title=None, **options):
+def show(image: Image.Image, title: str | None = None, **options: Any) -> bool:
     r"""
     Display a given image.
 
@@ -69,7 +71,7 @@ class Viewer:
 
     # main api
 
-    def show(self, image, **options):
+    def show(self, image: Image.Image, **options: Any) -> int:
         """
         The main function for displaying an image.
         Converts the given image to the target format and displays it.
@@ -87,16 +89,16 @@ class Viewer:
 
     # hook methods
 
-    format = None
+    format: str | None = None
     """The format to convert the image into."""
-    options = {}
+    options: dict[str, Any] = {}
     """Additional options used to convert the image."""
 
-    def get_format(self, image):
+    def get_format(self, image: Image.Image) -> str | None:
         """Return format name, or ``None`` to save as PGM/PPM."""
         return self.format
 
-    def get_command(self, file, **options):
+    def get_command(self, file: str, **options: Any) -> str:
         """
         Returns the command used to display the file.
         Not implemented in the base class.
@@ -104,15 +106,15 @@ class Viewer:
         msg = "unavailable in base viewer"
         raise NotImplementedError(msg)
 
-    def save_image(self, image):
+    def save_image(self, image: Image.Image) -> str:
         """Save to temporary file and return filename."""
         return image._dump(format=self.get_format(image), **self.options)
 
-    def show_image(self, image, **options):
+    def show_image(self, image: Image.Image, **options: Any) -> int:
         """Display the given image."""
         return self.show_file(self.save_image(image), **options)
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -129,7 +131,7 @@ class WindowsViewer(Viewer):
     format = "PNG"
     options = {"compress_level": 1, "save_all": True}
 
-    def get_command(self, file, **options):
+    def get_command(self, file: str, **options: Any) -> str:
         return (
             f'start "Pillow" /WAIT "{file}" '
             "&& ping -n 4 127.0.0.1 >NUL "
@@ -147,14 +149,14 @@ class MacViewer(Viewer):
     format = "PNG"
     options = {"compress_level": 1, "save_all": True}
 
-    def get_command(self, file, **options):
+    def get_command(self, file: str, **options: Any) -> str:
         # on darwin open returns immediately resulting in the temp
         # file removal while app is opening
         command = "open -a Preview.app"
         command = f"({command} {quote(file)}; sleep 20; rm -f {quote(file)})&"
         return command
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -180,7 +182,11 @@ class UnixViewer(Viewer):
     format = "PNG"
     options = {"compress_level": 1, "save_all": True}
 
-    def get_command(self, file, **options):
+    @abc.abstractmethod
+    def get_command_ex(self, file: str, **options: Any) -> tuple[str, str]:
+        pass
+
+    def get_command(self, file: str, **options: Any) -> str:
         command = self.get_command_ex(file, **options)[0]
         return f"({command} {quote(file)}"
 
@@ -190,11 +196,11 @@ class XDGViewer(UnixViewer):
     The freedesktop.org ``xdg-open`` command.
     """
 
-    def get_command_ex(self, file, **options):
+    def get_command_ex(self, file: str, **options: Any) -> tuple[str, str]:
         command = executable = "xdg-open"
         return command, executable
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -208,13 +214,15 @@ class DisplayViewer(UnixViewer):
     This viewer supports the ``title`` parameter.
     """
 
-    def get_command_ex(self, file, title=None, **options):
+    def get_command_ex(
+        self, file: str, title: str | None = None, **options: Any
+    ) -> tuple[str, str]:
         command = executable = "display"
         if title:
             command += f" -title {quote(title)}"
         return command, executable
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -231,12 +239,12 @@ class DisplayViewer(UnixViewer):
 class GmDisplayViewer(UnixViewer):
     """The GraphicsMagick ``gm display`` command."""
 
-    def get_command_ex(self, file, **options):
+    def get_command_ex(self, file: str, **options: Any) -> tuple[str, str]:
         executable = "gm"
         command = "gm display"
         return command, executable
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -247,12 +255,12 @@ class GmDisplayViewer(UnixViewer):
 class EogViewer(UnixViewer):
     """The GNOME Image Viewer ``eog`` command."""
 
-    def get_command_ex(self, file, **options):
+    def get_command_ex(self, file: str, **options: Any) -> tuple[str, str]:
         executable = "eog"
         command = "eog -n"
         return command, executable
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -266,7 +274,9 @@ class XVViewer(UnixViewer):
     This viewer supports the ``title`` parameter.
     """
 
-    def get_command_ex(self, file, title=None, **options):
+    def get_command_ex(
+        self, file: str, title: str | None = None, **options: Any
+    ) -> tuple[str, str]:
         # note: xv is pretty outdated.  most modern systems have
         # imagemagick's display command instead.
         command = executable = "xv"
@@ -274,7 +284,7 @@ class XVViewer(UnixViewer):
             command += f" -name {quote(title)}"
         return command, executable
 
-    def show_file(self, path, **options):
+    def show_file(self, path: str, **options: Any) -> int:
         """
         Display given file.
         """
@@ -304,7 +314,7 @@ if sys.platform not in ("win32", "darwin"):  # unixoids
 class IPythonViewer(Viewer):
     """The viewer for IPython frontends."""
 
-    def show_image(self, image, **options):
+    def show_image(self, image: Image.Image, **options: Any) -> int:
         ipython_display(image)
         return 1
 

tox.ini

@@ -33,6 +33,7 @@ commands =
 [testenv:mypy]
 skip_install = true
 deps =
+    ipython
     mypy==1.7.1
     numpy
 extras =