Graph([('A',1)]).adjacency_matrix() raises exception

[Georgi Guninski]

In both 9.6 and https://sagecell.sagemath.org/

Graph([('A',1)]).adjacency_matrix()

raises exception

TypeError: '<' not supported between instances of 'int' and 'str'

[John H Palmieri]

Please read the help message for adjaceny_matrix.

    g = Graph([('A',1)])

    g.adjacency_matrix?

prints, among other things:

   * "vertices" -- list (default: "None"); the ordering of the
     vertices defining how they should appear in the matrix. By
     default, the ordering given by "GenericGraph.vertices()" with
     "sort=True" is used. If the vertices are not comparable, the
     keyword "vertices" must be used to specify an ordering, or a
     TypeError exception will be raised.

Your vertices are not comparable.

[John H Palmieri]

By the way, I see this error message:

    TypeError: Vertex labels are not comparable. You must specify an ordering using parameter ``vertices``

Indeed, this works:

    g.adjacency_matrix(vertices=['A', 1])