networkx.algorithms.tree.recognition.is_forest

is_forest(G)[source]

Returns True if G is a forest.

A forest is a graph with no undirected cycles.

For directed graphs, G is a forest if the underlying graph is a forest. The underlying graph is obtained by treating each directed edge as a single undirected edge in a multigraph.

Parameters
Ggraph

The graph to test.

Returns
bbool

A boolean that is True if G is a forest.

See also

is_branching

Notes

In another convention, a directed forest is known as a polyforest and then forest corresponds to a branching.