CODEWITHSUNDEEP
pythonpandasnetworkx
LdM
LdM

Reputation: 704

How to get new edgelists after manipulating graphs

Is there any way to create a dataframe with data from a network?

For example, if I build a graph from an edgelist

G = nx.from_pandas_edgelist(df, 'Col1', 'Col2')

and then I manipulate the network a bit (e.g., removing nodes or calculating all the triangles), and I draw it

G1 = nx.triangles(G)
nx.draw(G1, with_labels=True)

would it be possible to extract the new data that I am plotting? How?

Upvotes: 0

Views: 137

Answers (1)

adrianop01
adrianop01

Reputation: 600

Try G.subgraph(list_of_node_indices).copy(). In the case of nx.triangles, it will return a dict with node name as the keys. What you can do is to extract keys with zero value (assuming you want to filter all nodes containing at least one triangle).

Example

G = nx.Graph()
G.add_edge(1,2)
G.add_edge(2,3)
G.add_edge(3,4)
G.add_edge(4,2)
G.add_edge(4,1)
G.add_edge(5,1)
G.add_edge(6,1)
G.add_edge(6,7)
G.add_edge(7,8)
G1 = G.subgraph([ i[0] for i in nx.triangles(G).items() if not i[1]]).copy()

nx.draw(G)

enter image description here

print(nx.triangles(G))

{1: 1, 2: 2, 3: 1, 4: 2, 5: 0, 6: 0, 7: 0, 8: 0}

#only node 6,7,8 is included
print(nx.to_pandas_edgelist(G1))

   source  target
0       6       7
1       7       8

Upvotes: 1

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