Imagine you are given a network of nodes. Node objects contain no extra data except a list of neighbor nodes to which they are connected. Your goal is to write a copy function that will duplicate the entire structure of a graph that has already been instantiated in memory. The function takes a single starting node as input and outputs a complete…

copy_node.py

class Node:
    def __init__(self, nbrs):
        self.nbrs = nbrs
    
    def add_nbr(self, node_nbr):
        self.nbrs.append(node_nbr)
        
    def copy(self):
        return self.copy_recurse({})
        
    def copy_recurse(self, hash):
        if self in hash: return hash[self]
        node_return = Node([])
        hash[self] = node_return
        for i in self.nbrs:
            node_return.add_nbr(i.copy_recurse(hash))
        return node_return