diff --git a/machine_learning/frequent_pattern_growth.py b/machine_learning/frequent_pattern_growth.py
index 21a502bd9..5d743a250 100644
--- a/machine_learning/frequent_pattern_growth.py
+++ b/machine_learning/frequent_pattern_growth.py
@@ -240,7 +240,7 @@ def ascend_tree(leaf_node: TreeNode, prefix_path: list[str]) -> None:
         ascend_tree(leaf_node.parent, prefix_path)
 
 
-def find_prefix_path(base_pat: frozenset, tree_node: TreeNode | None) -> dict:
+def find_prefix_path(_: frozenset, tree_node: TreeNode | None) -> dict:
     """
     Find the conditional pattern base for a given base pattern.