Function update_header

machine_learning/frequent_pattern_growth.py:173–210

Update the header table with a node link. Args: node_to_test: The node to be updated in the header table. target_node: The node to link to. Example: >>> data_set = [ ... ['A', 'B', 'C'], ... ['A', 'C'], ... ['A', 'B', 'E'], ... ['A', 'B'

(node_to_test: TreeNode, target_node: TreeNode)

def update_header(node_to_test: TreeNode, target_node: TreeNode) -> TreeNode:
    """
    Update the header table with a node link.

    Args:
        node_to_test: The node to be updated in the header table.
        target_node: The node to link to.

    Example:
    >>> data_set = [
    ...    ['A', 'B', 'C'],
    ...    ['A', 'C'],
    ...    ['A', 'B', 'E'],
    ...    ['A', 'B', 'C', 'E'],
    ...    ['B', 'E']
    ... ]
    >>> min_sup = 2
    >>> fp_tree, header_table = create_tree(data_set, min_sup)
    >>> fp_tree
    TreeNode('Null Set', 1, None)
    >>> node1 = TreeNode("A", 3, None)
    >>> node2 = TreeNode("B", 4, None)
    >>> node1
    TreeNode('A', 3, None)
    >>> node1 = update_header(node1, node2)
    >>> node1
    TreeNode('A', 3, None)
    >>> node1.node_link
    TreeNode('B', 4, None)
    >>> node2.node_link is None
    True
    """
    while node_to_test.node_link is not None:
        node_to_test = node_to_test.node_link
    if node_to_test.node_link is None:
        node_to_test.node_link = target_node
    # Return the updated node
    return node_to_test


def ascend_tree(leaf_node: TreeNode, prefix_path: list[str]) -> None: