The graph G can be grown in several ways. NetworkX includes many graph generator functions and facilities to read and write graphs in many formats. To get started though we’ll look at simple manipulations. You can add one node at a time,

G.add_node(1)

add a list of nodes,

G.add_nodes_from([2, 3])

or add any iterable container of nodes. You can also add nodes along with node attributes if your container yields 2-tuples (node, node_attribute_dict). Node attributes are discussed further below.

H = nx.path_graph(10)
G.add_nodes_from(H)

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Note that G now contains the nodes of H as nodes of G. In contrast, you could use the graph H as a node in G.

G.add_node(H)

The graph G now contains H as a node. This flexibility is very powerful as it allows graphs of graphs, graphs of files, graphs of functions and much more. It is worth thinking about how to structure your application so that the nodes are useful entities. Of course you can always use a unique identifier in G and have a separate dictionary keyed by identifier to the node information if you prefer.

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You should not change the node object if the hash depends on its contents.