Function ascend_tree

machine_learning/frequent_pattern_growth.py:213–240

Ascend the FP-Tree from a leaf node to its root, adding item names to the prefix path. Args: leaf_node: The leaf node to start ascending from. prefix_path: A list to store the item as they are ascended. Example: >>> data_set = [ ... ['A', 'B', 'C'],

(leaf_node: TreeNode, prefix_path: list[str])

def ascend_tree(leaf_node: TreeNode, prefix_path: list[str]) -> None:
    """
    Ascend the FP-Tree from a leaf node to its root, adding item names to the prefix
    path.

    Args:
        leaf_node: The leaf node to start ascending from.
        prefix_path: A list to store the item as they are ascended.

    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)

    >>> path = []
    >>> ascend_tree(fp_tree.children['A'], path)
    >>> path # ascending from a leaf node 'A'
    ['A']
    """
    if leaf_node.parent is not None:
        prefix_path.append(leaf_node.name)
        ascend_tree(leaf_node.parent, prefix_path)


def find_prefix_path(base_pat: frozenset, tree_node: TreeNode | None) -> dict:  # noqa: ARG001