fix: forward extra kwargs from create_node to node_class

docs/source/index.rst

@@ -703,8 +703,8 @@ Extend the Node class for specialized functionality:
     from treelib import Node, Tree
 
     class FileNode(Node):
-        def __init__(self, tag, identifier=None, size=0, file_type="unknown"):
-            super().__init__(tag, identifier)
+        def __init__(self, tag, identifier=None, size=0, file_type="unknown", **kwargs):
+            super().__init__(tag, identifier, **kwargs)
             self.size = size
             self.file_type = file_type
 

tests/test_tree.py

@@ -711,6 +711,18 @@ class SubTree(Tree):
         node = tree.create_node()
         self.assertTrue(isinstance(node, SubNode))
 
+    def test_create_node_forwards_kwargs_to_node_class(self):
+        class FileNode(Node):
+            def __init__(self, tag=None, identifier=None, size=0, **kwargs):
+                super().__init__(tag=tag, identifier=identifier, **kwargs)
+                self.size = size
+
+        tree = Tree(node_class=FileNode)
+        node = tree.create_node("Large File", "big_file", size=1024)
+        self.assertTrue(isinstance(node, FileNode))
+        self.assertEqual(node.size, 1024)
+        self.assertEqual(tree["big_file"].size, 1024)
+
     def test_shallow_copy_hermetic_pointers(self):
         # tree 1
         # Hárry

treelib/tree.py

@@ -853,6 +853,7 @@ def create_node(
         identifier: Optional[str] = None,
         parent: Optional[Union[Node, str]] = None,
         data: Any = None,
+        **kwargs: Any,
     ) -> Node:
         """
         Create and add a new node to the tree.
@@ -867,6 +868,8 @@ def create_node(
             parent: Parent node identifier, Node object, or None for root.
                    Must be None if tree is empty, must exist if tree has nodes.
             data: Optional user data to associate with this node.
+            **kwargs: Extra keyword arguments forwarded to the tree's
+                     ``node_class`` constructor, for custom Node subclasses.
 
         Returns:
             Node: The newly created Node object.
@@ -896,7 +899,7 @@ def create_node(
                 tree.create_node("Baby", "baby", parent="me",
                                data={"age": 1, "cute": True})
         """
-        node = self.node_class(tag=tag, identifier=identifier, data=data)
+        node = self.node_class(tag=tag, identifier=identifier, data=data, **kwargs)
         self.add_node(node, parent)
         return node