# Eulerian Cycle of a Digraph

 2 Hello, Is there a function to do an Eulerian cycle of a digraph? eulerian_cycle works on undirected graphs, but not on digraphs. Basically I'm looking for an equivalent to Mathematica's EulerianCycle. Does this exist? Thanks in advance. asked Jan 06 '11 Eviatar Bach 653 ● 4 ● 22 ● 34

 2 Are you sure about eulerian_cycle? I think it's eulerian_circuit in Sage (?). But it does seem to only work for undirected graphs... I would say this is a start. sage: D = DiGraph('IRAaDCIIOWEOKcPWAo') sage: D.is_eulerian() True  In fact, the code basically finds the circuit, but doesn't keep it like eulerian_circuit does. So it could be modified to keep it, just like eulerian_circuit. However, things get bad when we convert, because it doesn't keep double edges... hmmm... sage: E = D.to_undirected() sage: E.eulerian_circuit() False  Anyway, this could probably be implemented pretty easily. I highly suggest you post about this on sage-devel, and/or file a ticket at trac.sagemath.org if one doesn't already exist for this. posted Jan 06 '11 kcrisman 7427 ● 17 ● 76 ● 166 Thank you! I will take a look. Eviatar Bach (Jan 07 '11)

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