networkx.algorithms.reciprocity.reciprocity¶

reciprocity
(G, nodes=None)[source]¶ Compute the reciprocity in a directed graph.
The reciprocity of a directed graph is defined as the ratio of the number of edges pointing in both directions to the total number of edges in the graph. Formally, \(r = {(u,v) \in G(v,u) \in G} / {(u,v) \in G}\).
The reciprocity of a single node u is defined similarly, it is the ratio of the number of edges in both directions to the total number of edges attached to node u.
Parameters:  G (graph) – A networkx directed graph
 nodes (container of nodes, optional (default=whole graph)) – Compute reciprocity for nodes in this container.
Returns: out – Reciprocity keyed by node label.
Return type: dictionary
Notes
The reciprocity is not defined for isolated nodes. In such cases this function will return None.