Path

Your task is to find a path from a node $a$ to a node $b$ in a given tree. A path is a route in the tree that follows the connections between the nodes.

For example, in the tree below, the path from the node $3$ to the node $2$ is $[3, 4, 1, 2]$, and the path from the node $1$ to the node $7$ is $[1, 4, 7]$.

In a file treepath.py, implement the function find_path, whose parameters are a reference to the root of a tree and the node identifiers $a$ and $b$. The function returns the path as a list, or None if there is no path.

class Node:
    def __init__(self, value, children=None):
        self.value = value
        self.children = children if children else []

    def __repr__(self):
        if self.children == []:
            return f"Node({self.value})"
        else:
            return f"Node({self.value}, {self.children})"

def find_path(node, a, b):
    # TODO

if __name__ == "__main__":
    tree1 = Node(1, [Node(4, [Node(3), Node(7)]),
                     Node(5),
                     Node(2, [Node(6)])])
    print(find_path(tree1, 3, 2)) # [3, 4, 1, 2]
    print(find_path(tree1, 1, 7)) # [1, 4, 7]
    print(find_path(tree1, 5, 5)) # [5]
    print(find_path(tree1, 7, 3)) # [7, 4, 3]
    print(find_path(tree1, 4, 8)) # None

    tree2 = Node(1, [Node(2, [Node(3, [Node(4)])])])
    print(find_path(tree2, 1, 4)) # [1, 2, 3, 4]
    print(find_path(tree2, 4, 1)) # [4, 3, 2, 1]
    print(find_path(tree2, 2, 3)) # [2, 3]

    tree3 = Node(1, [Node(2), Node(3), Node(4)])
    print(find_path(tree3, 2, 3)) # [2, 1, 3]
    print(find_path(tree3, 1, 2)) # [1, 2]
    print(find_path(tree3, 5, 5)) # None