hobbsCalc.py 文件源码

def traverse_tree(tree, pro):
    """ Traverse a tree in a left-to-right, breadth-first manner,
    proposing any NP encountered as an antecedent. Returns the 
    tree and the position of the first possible antecedent.

    Args:
        tree: the tree being searched
        pro: the pronoun being resolved (string)
    """
    # Initialize a queue and enqueue the root of the tree
    queue = Queue.Queue()
    queue.put(tree)
    while not queue.empty():
        node = queue.get()
        # if the node is an NP, return it as a potential antecedent
        if "NP" in node.label() and match(tree, get_pos(tree,node), pro):
            return tree, get_pos(tree, node)
        for child in node:
            if isinstance(child, nltk.Tree):
                queue.put(child)
    # if no antecedent is found, return None
    return None, None