Creating a Path Graph Using Networkx in Python

Last Updated : 29 Apr, 2021

A path graph is a connected graph denoted by P_n if it contains n nodes. Nodes are connected in form of a straight line in a path graph. Here we will discuss how networkx module can be used to generate one using its inbuilt path_graph() function.

Properties of Path Graph:

The number of nodes in a path graph(P_n) is N.
The number of edges in a path graph(P_n) is N-1.
The diameter of the path graph(P_n) i.e maximum distance between any pair of vertices is N-1 which is between 1st and last node.
The chromatic number of Path Graph is 2.
Nodes are assigned labels from 0 to N-1
Terminal vertices have degree 1 and every other vertex has degree 2.
A path graph is a connected graph.
Path graph contains no cycle in it.
Although the path graph is connected but the removal of any edge will make it unconnected as no cycle is there in Path Graph.
It is a Planar Graph.

Functions used

We will use the networkx module for realizing a Path graph. It comes with an inbuilt function networkx.path_graph() and can be illustrated using the networkx.draw() method. This method is straightforward method of creating a desired path graph using appropriate parameters.

Syntax: path_graph(n, create_using=None)

Parameter:

n: Number of nodes we want in path graph.

create_using: We can simply pass None or pass nx.DiGraph() as a value to this argument sending nx.Digraph() will lead to creation of a directed path graph.

Approach:

Import module
Create path graph object using path_graph() function as mentioned above.
Pass appropriate parameters to the functions
Display plot

Program:

Python3

# import required module
import networkx as nx
 
# create object
G = nx.path_graph(5, create_using=nx.DiGraph())
 
# illustrate graph
nx.draw(G, node_color='green')