Warning

This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.

topological_sort_recursive

topological_sort_recursive(G, nbunch=None, reverse=False)

Return a list of nodes in topological sort order.

A topological sort is a nonunique permutation of the nodes such that an edge from u to v implies that u appears before v in the topological sort order.

Parameters:

• G (NetworkX digraph) –
• nbunch (container of nodes (optional)) – Explore graph in specified order given in nbunch
• reverse (bool, optional) – Return postorder instead of preorder if True. Reverse mode is a bit more efficient.

Raises:

• NetworkXError – Topological sort is defined for directed graphs only. If the graph G is undirected, a NetworkXError is raised.
• NetworkXUnfeasible – If G is not a directed acyclic graph (DAG) no topological sort exists and a NetworkXUnfeasible exception is raised.

Notes

This is a recursive version of topological sort.

See also

topological_sort(), is_directed_acyclic_graph()