[joss] How to get edges incident to a vertex?

[szhorvat]

I was wondering about how one might implement certain graph algorithms, such as basic graph traversal, or obtaining a cycle basis in terms of edges, perhaps compute the edge-cycle matrix (see #505).

For such operations, it is necessary to be able to access the incident edges of a node (similar to .neighbors() or .adj() but returning edges). How can I do this?

[IvanIsCoding]

For directed graphs, the methods you are looking for are:

• PyDiGraph.out_edges: for outgoing edges
• PyDiGraph.in_edges: for incident edges

To achieve an equivalent behaviour on undirected graphs, the current best way is to:

• Call PyGraph.neighbors, as you pointed out
• Then call PyGraph.get_edge_data with the node indices as you loop through the neighbors