how to add subgraph with (new nodes, new edges) to an existed graph in python

Question

I'm trying to add new nodes (red dots) with new edges (green lines) to be places diagonaly new color and positions to this grid graph

import networkx as nx
import matplotlib.pyplot as plt

G = nx.grid_graph(dim=[5, 5])

nodes = list(G.nodes)
edges = list(G.edges)

p = []
for i in range(0, 5):
    for j in range(0, 5):
        p.append([i, j])


for i in range(0, len(nodes)):
    G.nodes[nodes[i]]['pos'] = p[i]

pos = {}
for i in range(0, len(nodes)):
    pos[nodes[i]] = p[i]

nx.draw(G, pos)
plt.show()

Answer 1

Sorry, your question is not clear for me, but you can create list of edges and then use G.add_edges_from() to add nodes & edges to your initial graph

Probably you should define algorithm to find coordinates / labels of new nodes, then construct edges and add by G.add_edges_from()

G = nx.grid_graph(dim=[5, 5])

new_edges = [((0.5, 1.5), (0.5, 2.5)),
             ((0.5, 1.5), (0, 2)),
             ((0.5, 2.5), (0, 2))]

G.add_edges_from(new_edges)

nx.draw(G, pos={n:n for n in G.nodes()})
plt.show()