sorts: type cocktail shaker sort for comparable items (#15278)

Co-authored-by: Gavin-Yau <2695188238@qq.com>

Author: ElenaGe216

sorts/cocktail_shaker_sort.py

@@ -4,8 +4,14 @@
 https://en.wikipedia.org/wiki/Cocktail_shaker_sort
 """
 
+from typing import Protocol
 
-def cocktail_shaker_sort(arr: list[int]) -> list[int]:
+
+class Comparable(Protocol):
+    def __lt__(self, other: object, /) -> bool: ...
+
+
+def cocktail_shaker_sort[T: Comparable](arr: list[T]) -> list[T]:
     """
     Sorts a list using the Cocktail Shaker Sort algorithm.
 
@@ -28,6 +34,10 @@ def cocktail_shaker_sort(arr: list[int]) -> list[int]:
     Traceback (most recent call last):
         ...
     TypeError: 'tuple' object does not support item assignment
+    >>> cocktail_shaker_sort([1, "a"])  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+        ...
+    TypeError: ...
     """
     start, end = 0, len(arr) - 1
 

tests/test_sorts.py

@@ -115,6 +115,7 @@ def test_sort_matches_builtin(sort, case):
         bubble_sort_iterative,
         bubble_sort_recursive,
         circle_sort,
+        cocktail_shaker_sort,
         gnome_sort,
         insertion_sort,
         merge_sort,