test_digraph_arc a Python code which defines a number of examples of directed graphs ("digraphs") in terms of an arc list (pairs of nodes connected by a link).
The information on this web page is distributed under the MIT license.
test_digraph_arc is available in a Fortran90 version and a MATLAB version and an Octave version and a Python version.
test_digraph_adj, a Python code which defines a number of examples of directed graphs ("digraphs"), The definition is stored as an adjacency matrix.