Networkx DFS Tree

Networkx is a Python library used for analyzing and creating graphs. In this article, we will be discussing the DFS(Depth-First Search) algorithm in Networkx and how to generate a DFS tree.

DFS Algorithm

DFS is an algorithm used to traverse a graph or tree data structure. The algorithm starts at a root node and explores as far as possible along each branch. When the algorithm reaches the end of a branch, it backtracks to the last node with unexplored branches.

The DFS algorithm can be implemented using recursion or a stack data structure. In Networkx, the DFS algorithm is implemented using a stack.

Generating a DFS Tree

A DFS tree is a tree that is generated while performing a DFS traversal on a graph. The DFS tree is a tree data structure that represents the traversal of the graph. The DFS tree is generated by adding edges to a tree that connect nodes as the DFS traversal progresses.

In Networkx, the DFS algorithm can be used to generate the DFS tree. The dfs_tree() function takes a graph object and a starting node as parameters and returns a tree object representing the DFS traversal of the graph starting from the given node.

Here is an example of how to generate a DFS tree using Networkx:

import networkx as nx

# Create a graph object
G = nx.Graph()

# Add nodes to the graph object
G.add_nodes_from([1, 2, 3, 4, 5, 6])

# Add edges to the graph object
G.add_edges_from([(1, 2), (2, 3), (2, 4), (3, 5), (4, 5), (5, 6)])

# Generate DFS tree from node 1
T = nx.dfs_tree(G, source=1)

# Print the DFS tree
print(T.edges())

Output:

[(1, 2), (2, 3), (3, 5), (5, 4), (5, 6)]

The output shows the edges of the DFS tree generated from node 1.

Conclusion

The DFS algorithm in Networkx is a powerful graph traversal algorithm that can be used to generate a DFS tree. The DFS tree is a tree data structure that represents the traversal of the graph. The dfs_tree() function in Networkx can be used to generate the DFS tree.