Note

This documents the development version of NetworkX. Documentation for the current release can be found here.

networkx.algorithms.lowest_common_ancestors.lowest_common_ancestor

lowest_common_ancestor(G, node1, node2, default=None)[source]

Compute the lowest common ancestor of the given pair of nodes.

Parameters
GNetworkX directed graph
node1, node2nodes in the graph.
defaultobject

Returned if no common ancestor between node1 and node2

Returns
The lowest common ancestor of node1 and node2,
or default if they have no common ancestors.

Notes

Only defined on non-null directed acyclic graphs. Takes n log(n) time in the size of the graph. See all_pairs_lowest_common_ancestor when you have more than one pair of nodes of interest.