Return the number of nodes of the graph with degree equal to 1.
A vertex with degree equal to 1 is also called a leaf.
- G : graph
- A NetworkX graph.
- numNodes : int
- The number of nodes in the graph with degree equal to 1.
number_of_nodes_of_degree_k, number_of_min_degree_nodes, number_of_max_degree_nodes
>>> G = nx.path_graph(3) # Path on 3 nodes >>> nx.number_of_leaves(G) 2