diff --git a/graphs/graph_adjacency_list.py b/graphs/graph_adjacency_list.py
index c901e2cf3dac..34014d69dfb8 100644
--- a/graphs/graph_adjacency_list.py
+++ b/graphs/graph_adjacency_list.py
@@ -61,6 +61,15 @@ def add_vertex(self, vertex: T) -> None:
         """
         Adds a vertex to the graph. If the given vertex already exists,
         a ValueError will be thrown.
+
+        >>> g = GraphAdjacencyList(vertices=[], edges=[], directed=False)
+        >>> g.add_vertex("A")
+        >>> g.adj_list
+        {'A': []}
+        >>> g.add_vertex("A")
+        Traceback (most recent call last):
+        ...
+        ValueError: Incorrect input: A is already in the graph.
         """
         if self.contains_vertex(vertex):
             msg = f"Incorrect input: {vertex} is already in the graph."
diff --git a/machine_learning/apriori_algorithm.py b/machine_learning/apriori_algorithm.py
index 09a89ac236bd..5c3e2baba2c2 100644
--- a/machine_learning/apriori_algorithm.py
+++ b/machine_learning/apriori_algorithm.py
@@ -11,6 +11,7 @@
 Examples: https://www.kaggle.com/code/earthian/apriori-association-rules-mining
 """
 
+from collections import Counter
 from itertools import combinations
 
 
@@ -44,11 +45,16 @@ def prune(itemset: list, candidates: list, length: int) -> list:
     >>> prune(itemset, candidates, 3)
     []
     """
+    itemset_counter = Counter(tuple(item) for item in itemset)
     pruned = []
     for candidate in candidates:
         is_subsequence = True
         for item in candidate:
-            if item not in itemset or itemset.count(item) < length - 1:
+            item_tuple = tuple(item)
+            if (
+                item_tuple not in itemset_counter
+                or itemset_counter[item_tuple] < length - 1
+            ):
                 is_subsequence = False
                 break
         if is_subsequence:
diff --git a/maths/test_factorial.py b/maths/test_factorial.py
index d80d88add745..1795ebba194f 100644
--- a/maths/test_factorial.py
+++ b/maths/test_factorial.py
@@ -33,5 +33,11 @@ def test_negative_number(function):
         function(-3)
 
 
+@pytest.mark.parametrize("function", [factorial, factorial_recursive])
+def test_float_number(function):
+    with pytest.raises(ValueError):
+        function(1.5)
+
+
 if __name__ == "__main__":
     pytest.main(["-v", __file__])