networkx.algorithms.boundary.edge_boundary¶

edge_boundary
(G, nbunch1, nbunch2=None, data=False, keys=False, default=None)[source]¶ Returns the edge boundary of
nbunch1
.The edge boundary of a set S with respect to a set T is the set of edges (u, v) such that u is in S and v is in T. If T is not specified, it is assumed to be the set of all nodes not in S.
Parameters:  G (NetworkX graph)
 nbunch1 (iterable) – Iterable of nodes in the graph representing the set of nodes whose edge boundary will be returned. (This is the set S from the definition above.)
 nbunch2 (iterable) – Iterable of nodes representing the target (or “exterior”) set of
nodes. (This is the set T from the definition above.) If not
specified, this is assumed to be the set of all nodes in
G
not innbunch1
.  keys (bool) – This parameter has the same meaning as in
MultiGraph.edges()
.  data (bool or object) – This parameter has the same meaning as in
MultiGraph.edges()
.  default (object) – This parameter has the same meaning as in
MultiGraph.edges()
.
Returns: An iterator over the edges in the boundary of
nbunch1
with respect tonbunch2
. Ifkeys
,data
, ordefault
are specified andG
is a multigraph, then edges are returned with keys and/or data, as inMultiGraph.edges()
.Return type: iterator
Notes
Any element of
nbunch
that is not in the graphG
will be ignored.nbunch1
andnbunch2
are usually meant to be disjoint, but in the interest of speed and generality, that is not required here.