Find all parent nodes of a node in a tree

Question

I am creating a tree in python, and I had a method to find a path from the parent to the root node of the tree. That is as follows:

def get_sub_net(self, index):
    node = self.nodes[index]
    sub_net = []
    sub_net.append(node)
    while node.parent is not None:
        node = node.parent
        sub_net.append(node)
    return sub_net[::-1]

Now I am trying to allow for each node to have multiple parents, and I am running into trouble.

def sub_net(self, index):
    node = self.nodes[index]
    sub_net = []
    if node.parents == None:
        return sub_net
    else:
        sub_net += node.parents
        for i in node.parents:
            while i is not None:
                sub_net += i.parents
                node = i
                break
    return sub_net[::-1]

@Noreddine-Kessa pointed out that this would be a graph, and not a tree, which is correct. However, I also solved my own problem, the solution I used i

def recursive_sub_net(self, node):
    sub_net = []
    sub_net.append(node)

    if node.parents is not None:
        for i in node.parents:
            sub_net += self.recursive_sub_net(i)

    return sub_net

Answer 1

根据定义，树中的每个节点都有一个父节点（并且可以有许多祖先），如果需要使用节点网络（而不是树），则应该使用图。