networkx.algorithms.dag.ancestors

ancestors(G, source)[source]

Returns all nodes having a path to source in G.

Parameters
GNetworkX Graph
sourcenode in G
Returns
set()

The ancestors of source in G

Raises
NetworkXError

If node source is not in G.

See also

descendants

Examples

>>> DG = nx.path_graph(5, create_using=nx.DiGraph)
>>> sorted(list(nx.ancestors(DG, 2)))
[0, 1]