Is there an easy way to prune disconnected networks in a NetworkX graph?

Question

I'm using Python's NetworkX package to calculate a bunch of network statistics for networks of varying size. I'm sweeping an independent parameter that systematically prunes edges, so sometimes a small network will become disconnected from the main network. Is there an easy way to detect and remove those smaller disconnected networks in NetworkX?

Answer 1

Sorin is correct. The function is called connected_component_subgraphs in NetworkX.

Documentation: http://networkx.github.io/documentation/latest/reference/generated/networkx.algorithms.components.connected.connected_component_subgraphs.html#networkx.algorithms.components.connected.connected_component_subgraphs

Here's some code that finds the largest network in a NetworkX graph:

cur_graph = # whatever graph you're working with

if not nx.is_connected(cur_graph):
    # get a list of unconnected networks
    sub_graphs = nx.connected_component_subgraphs(cur_graph)

    main_graph = sub_graphs[0]

    # find the largest network in that list
    for sg in sub_graphs:
        if len(sg.nodes()) > len(main_graph.nodes()):
            main_graph = sg

    cur_graph = main_graph