import networkx as nx

def main():
    G = nx.Graph()
    G.add_node("A")
    G.add_node("B")
    G.add_node(3)
    G.add_edge("A", "B")
    G.add_edge("B", 3)
    print(G.nodes())
    print(G.edges())
    print(G.degree())

    nx.draw(G, with_labels=True)

if __name__ == "__main__":
    main()