@property
    def edges(self):
        if self._edges is None:
            output = set()
            for face in self.faces:
                for i in range(len(face)):
                    edge = tuple(sorted([face[i], face[i - 1]]))
                    output.add(edge)
            self._edges = FiniteSet(*output)
        return self._edges
Given the faces of the polyhedra we can get the edges.
dataset/ETHPy150Open sympy/sympy/sympy/combinatorics/polyhedron.py/Polyhedron.edges