in_degree

DiGraph.in_degree(nbunch=None, weight=None)[source]

Return an iterator for (node, in-degree) or in-degree for single node.

The node in-degree is the number of edges pointing in to the node. This function returns the in-degree for a single node or an iterator for a bunch of nodes or if nothing is passed as argument.

Parameters:
  • nbunch (iterable container, optional (default=all nodes)) – A container of nodes. The container will be iterated through once.
  • weight (string or None, optional (default=None)) – The edge attribute that holds the numerical value used as a weight. If None, then each edge has weight 1. The degree is the sum of the edge weights adjacent to the node.
Returns:

  • If a single node is requested
  • deg (int) – In-degree of the node
  • OR if multiple nodes are requested
  • nd_iter (iterator) – The iterator returns two-tuples of (node, in-degree).

See also

degree(), out_degree()

Examples

>>> G = nx.DiGraph()
>>> nx.add_path(G, [0, 1, 2, 3])
>>> G.in_degree(0) # node 0 with degree 0
0
>>> list(G.in_degree([0,1]))
[(0, 0), (1, 1)]