typing: fix invalid-assignment errors

computer_vision/mean_threshold.py

@@ -21,7 +21,7 @@ def mean_threshold(image: Image.Image) -> Image.Image:
 
     for j in range(width):
         for i in range(height):
-            pixels[i, j] = 255 if pixels[i, j] > mean else 0
+            image.putpixel((i, j), 255 if pixels[i, j] > mean else 0)
     return image
 
 

other/dancing_links.py

@@ -21,6 +21,12 @@
 class DLXNode:
     """Represents a node in the Dancing Links structure."""
 
+    left: "DLXNode"
+    right: "DLXNode"
+    up: "DLXNode"
+    down: "DLXNode"
+    column: "ColumnNode | None"
+
     def __init__(self) -> None:
         self.left = self.right = self.up = self.down = self
         self.column = None

sorts/benchmark_sorts.py

@@ -20,25 +20,30 @@
 
 import random
 import sys
 from collections.abc import Callable, Sequence
 from itertools import pairwise
 from timeit import timeit
 from typing import Protocol
 
+
+class SortFunction(Protocol):
+    def __call__[T](self, collection: list[T], /) -> Sequence[T]: ...
+
+
 from sorts.bubble_sort import bubble_sort_iterative
 from sorts.cocktail_shaker_sort import cocktail_shaker_sort
 from sorts.comb_sort import comb_sort
 from sorts.gnome_sort import gnome_sort
 from sorts.heap_sort import heap_sort
 from sorts.insertion_sort import insertion_sort
 from sorts.merge_sort import merge_sort
 from sorts.quick_sort import quick_sort
 from sorts.selection_sort import selection_sort
 from sorts.shell_sort import shell_sort
 from sorts.tim_sort import tim_sort
 
 # name -> callable.  Every callable accepts a list and returns the sorted list.
-SORTS: dict[str, Callable[[list[int]], Sequence[int]]] = {
+SORTS: dict[str, SortFunction] = {
     "bubble_sort": bubble_sort_iterative,
     "cocktail_shaker_sort": cocktail_shaker_sort,
     "comb_sort": comb_sort,