Return an iterator over all neighbors of node n.
Notes
It is faster to use the idiom “in G[0]”, e.g.
>>> G = nx.path_graph(4)
>>> [n for n in G[0]]
[1]
Examples
>>> G = nx.Graph() # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> G.add_path([0,1,2,3])
>>> [n for n in G.neighbors_iter(0)]
[1]