class SearchTree(object):
    def __init__(self, number, children):
        self.number = number
        self.children = children

foo = SearchTree(1,[SearchTree(2, [ SearchTree(4, [SearchTree(5, [])]) ] ), SearchTree(3, [])])

def larve_search(tree, goal):
    if not tree:
        # safety check
        return None
    elif tree.number == goal:
        return [tree.number]
    else:
        for node in tree.children:
            path = larve_search(node, goal)
            if path != None:
                return [tree.number] + path
        # no goal found in children, aborting
        return None