TreeNode¶

The TreeNode class is a recursive representation of a tree.

TreeNode Structure¶

Each node is a TreeNode object.

Example Structure:

We can import JSON data into a TreeNode object as follows:

TreeNode.from_dict(
  {
    "name": "root",
    "value": "root_value",
    "children": [
      {
        "name": "child1",
        "value": "child1_value",
        "children": [
          {
            "name": "child1_1",
            "value": "child1_1_value"
          }
        ]
      },
      {
        "name": "child2",
        "value": "child2_value",
        "children": [
          {
            "name": "child2_1",
            "value": "child2_1_value"
          }
        ]
      }
    ]
  })

Where:

name (optional) is a key that maps to the name of the node. If not provided, the name defaults to a UUID.
children is a list of child nodes, each of which is a TreeNode object.
Other key-value pairs can be stored in the node as needed, which in total form the payload of the node, which can be accessed using the payload property.

Attributes and Methods¶

Initialization¶

Each TreeNode can be initialized with an optional parent, name, and additional key-value pairs.

def __init__(self, *args, parent: Optional['TreeNode'] = None, name: Optional[str] = None,
             payload: Optional[Any], *args, **kwargs):
    # Initialization code here

If the payload argument is provided, that is used as payload. However, we also allow for the payload to be specified by arguments and key-word arguments, *args and **kwargs. If the name argument is provided, it is stored as the name of the node, otherwise a UUID is generated. If the parent argument is provided, the node is added as a child of the parent node.

Properties¶

name: Returns the name of the node.
children: Returns the list of children of the node.
payload: Returns the data stored in the node.

Methods¶

node(name: str) -> ‘TreeNode’: Retrieves the node with the given name.
add_child(name: Optional[str] = None, payload: Optional[Any], *args, **kwargs) -> ‘TreeNode’: Adds a child node to the tree.
root: Returns the root of the tree.

Tree API¶

The TreeNode class also provides a tree API that allows manipulation and construction of tree. Unlike the FlatForestNode class, it is not backed by a dictionary. It is a recursive representation of a tree that has fewer restrictions on what kind of objects can be stored in, for instance, the payload.

Example Usage¶

root = TreeNode(name='root', value='root_value')
child1 = root.add_child(name='child1', value='child1_value')
child1_1 = child1.add_child(name='child1_1', value='child1_1_value')
child2 = root.add_child(name='child2', value='child2_value')
child2_1 = child2.add_child(name='child2_1', value='child2_1_value')

other = TreeNode(name="other", value="other_value", parent=child1_1)
TreeNode(name="other2", value="other2_value", parent=other)

print(root.node('child1').value)  # Output: 'child1_value'
print(child1_1.root.name)         # Output: 'root'