Doctests + typehints in cocktail shaker sort (#2061)

* Doctests in cocktail shaker sort

* import doctest

* print(f"{cocktail_shaker_sort(unsorted) = }")

Co-authored-by: John Law <johnlaw.po@gmail.com>
Co-authored-by: Christian Clauss <cclauss@me.com>

sorts/cocktail_shaker_sort.py

@@ -1,6 +1,23 @@
-def cocktail_shaker_sort(unsorted):
+""" https://en.wikipedia.org/wiki/Cocktail_shaker_sort """
+
+
+def cocktail_shaker_sort(unsorted: list) -> list:
     """
     Pure implementation of the cocktail shaker sort algorithm in Python.
+    >>> cocktail_shaker_sort([4, 5, 2, 1, 2])
+    [1, 2, 2, 4, 5]
+
+    >>> cocktail_shaker_sort([-4, 5, 0, 1, 2, 11])
+    [-4, 0, 1, 2, 5, 11]
+
+    >>> cocktail_shaker_sort([0.1, -2.4, 4.4, 2.2])
+    [-2.4, 0.1, 2.2, 4.4]
+
+    >>> cocktail_shaker_sort([1, 2, 3, 4, 5])
+    [1, 2, 3, 4, 5]
+
+    >>> cocktail_shaker_sort([-4, -5, -24, -7, -11])
+    [-24, -11, -7, -5, -4]
     """
     for i in range(len(unsorted) - 1, 0, -1):
         swapped = False
@@ -20,7 +37,9 @@ def cocktail_shaker_sort(unsorted):
 
 
 if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
     user_input = input("Enter numbers separated by a comma:\n").strip()
     unsorted = [int(item) for item in user_input.split(",")]
-    cocktail_shaker_sort(unsorted)
+    print(f"{cocktail_shaker_sort(unsorted) = }")
-    print(unsorted)