Given an underlying graph G, to obtain all non-isomorphic directed graphs, I know that nauty has the directg function, and such function was been integrated in sagemath.
Read undirected loop-free graphs and replace their edges with multiple. Nauty's mulgraph can achieve this. (Isomorphic multigraphs derived from the same input are suppressed. If the input graphs are non-isomorphic then the output graphs are also.) Does SageMath have similar functionality, or is such functionality integrated?