Iterator over isolates in the graph. An *isolate* is a node with no neighbors (that is, with degree zero). For directed graphs, this means no in-neighbors and no out-neighbors. Parameters ---------- G : EasyGraph graph Returns ------- iterator An iterat
(G)
| 38 | |
| 39 | |
| 40 | def isolates(G): |
| 41 | """Iterator over isolates in the graph. |
| 42 | |
| 43 | An *isolate* is a node with no neighbors (that is, with degree |
| 44 | zero). For directed graphs, this means no in-neighbors and no |
| 45 | out-neighbors. |
| 46 | |
| 47 | Parameters |
| 48 | ---------- |
| 49 | G : EasyGraph graph |
| 50 | |
| 51 | Returns |
| 52 | ------- |
| 53 | iterator |
| 54 | An iterator over the isolates of `G`. |
| 55 | |
| 56 | Examples |
| 57 | -------- |
| 58 | To get a list of all isolates of a graph, use the :class:`list` |
| 59 | constructor:: |
| 60 | |
| 61 | >>> G = eg.Graph() |
| 62 | >>> G.add_edge(1, 2) |
| 63 | >>> G.add_node(3) |
| 64 | >>> list(eg.isolates(G)) |
| 65 | [3] |
| 66 | |
| 67 | To remove all isolates in the graph, first create a list of the |
| 68 | isolates, then use :meth:`Graph.remove_nodes_from`:: |
| 69 | |
| 70 | >>> G.remove_nodes_from(list(eg.isolates(G))) |
| 71 | >>> list(G) |
| 72 | [1, 2] |
| 73 | |
| 74 | For digraphs, isolates have zero in-degree and zero out_degre:: |
| 75 | |
| 76 | >>> G = eg.DiGraph([(0, 1), (1, 2)]) |
| 77 | >>> G.add_node(3) |
| 78 | >>> list(eg.isolates(G)) |
| 79 | [3] |
| 80 | |
| 81 | """ |
| 82 | return (n for n, d in G.degree().items() if d == 0) |
| 83 | |
| 84 | |
| 85 | def number_of_isolates(G): |
no test coverage detected