Depth First Search Python Implementation : Prints all the nodes of the graph

depth_first_search.py

def depth_first_search(graph, start_node):
    visited_neighbours = set() #Keep track of the node we have visited like breadcrumbs to know the path
    neighbours = [start_node] #list to store the neighbors. We will start with neigbors of void, the start node
    
    while (len(neighbours) != 0): #All the elements will be transversed by the time we have this list size as zero
        neighbour = neighbours.pop() #pop will take out randomly any one element and deletes from the list
        if neighbour not in visited_neighbours:
            visited_neighbours.add(neighbour)
            new_prospected_neighbours = graph[neighbour]
            #Need to remove neighbours which are already visted
            new_neighbours = new_prospected_neighbours - visited_neighbours 
            neighbours.extend(new_neighbours)
    return visited_neighbours        
            
    
depth_first_search(graph, 'A') 
#output: {'A', 'B', 'C', 'D', 'E', 'F', 'G'}