Python Coding challenge - Day 793| What is the output of the following Python Code?

 

Code Explanation:

Import the Library

import networkx as nx

networkx is a Python library used for creating, analyzing, and visualizing graphs (networks).

It can represent relationships between nodes — like people in a social network or cities connected by roads.

In short: nx is the alias for NetworkX to make commands shorter.

Create an Empty Graph Object

G = nx.Graph()

nx.Graph() creates an empty, undirected graph named G.

At this point, there are:

0 nodes

0 edges

Think of G as a blank network where you’ll soon add connections.

Add Edges (Connections Between Nodes)

G.add_edges_from([(1,2), (2,3)])

.add_edges_from() takes a list of tuples, where each tuple (a, b) represents an edge between node a and node b.

Here:

(1, 2) connects node 1 to node 2

(2, 3) connects node 2 to node 3

After this line:

Nodes: {1, 2, 3}

Edges: {(1, 2), (2, 3)}

Note: NetworkX automatically adds any missing nodes when you add edges.

Count the Number of Edges

print(G.number_of_edges())

.number_of_edges() returns the total count of edges currently in the graph G.

Since we added two edges — (1,2) and (2,3) — it prints:

Output:

2

500 Days Python Coding Challenges with Explanation