'Walk back until first branch found in networkx graph

Given a directed graph, I want to start at a leaf node, and walk back (breadth first) until I find the first node with more than one successor (or a degree greater than 1).

I can do it with this code, but nx.ancestors() involves reading in all the nodes that have a path to the leaf node, which can be very large.

for ancestor in reversed(list(nx.ancestors(DG, leaf_node))):
   if DG.out_degree(ancestor) > 1:  # branching point reached
      # print("found")

Is there a way I can do this faster, potentially going back one node at a time and checking for degree? Thanks!

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source

'Walk back until first branch found in networkx graph

Sources

Related Questions