Note

This is the documentation for the current state of the development branch of rustworkx. The documentation or APIs here can change prior to being released.

rustworkx.PyDiGraph.predecessor_indices#

PyDiGraph.predecessor_indices(node, /)#

Return a list of predecessor node indices in a directed graph

A predecessor is defined as a node that has a directed edge pointing to the specified node. In a multigraph, where two nodes can be connected by multiple edges, each predecessor node index is returned only once.

>>> G = rx.PyDiGraph()
>>> G.add_nodes_from(["A", "B", "C", "D", "E"])
NodeIndices[0, 1, 2, 3, 4]
>>> G.extend_from_edge_list([(0, 3), (1, 3), (2, 3), (3, 4)])
>>> G.predecessor_indices(3)  # predecessors of the 'D' node
NodeIndices[2, 1, 0]

To get the data of these nodes, see [predecessors]

To filter the predecessors by the attributes of the connecting edge, see find_predecessors_by_edge().