(self)
return self._edges
Given the faces of the polyhedra we can get the edges.

        Examples
        ========

        >>> from sympy.combinatorics import Polyhedron
        >>> from sympy.abc import a, b, c
        >>> corners = (a, b, c)
        >>> faces = [(0, 1, 2)]
        >>> Polyhedron(corners, faces).edges
        {(0, 1), (0, 2), (1, 2)}
Given the faces of the polyhedra we can get the edges.
Given the faces of the polyhedra we can get the edges .
def edges(self):
        """
        Given the faces of the polyhedra we can get the edges.

        Examples
        ========

        >>> from sympy.combinatorics import Polyhedron
        >>> from sympy.abc import a, b, c
        >>> corners = (a, b, c)
        >>> faces = [(0, 1, 2)]
        >>> Polyhedron(corners, faces).edges
        {(0, 1), (0, 2), (1, 2)}

        """
        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
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