def test_undirected_vertex_has_attr(self):
""" Check if a directed vertex has a particular attribute """
v0 = DirectedVertex(val='v0', attrs={'city': 'Modena', 0: 1})
self.assertTrue(v0.has_attr('city'))
self.assertFalse(v0.has_attr('town'))
v0.del_attr('city')
self.assertFalse(v0.has_attr('city'))
def test_directed_vertex_del_attr(self):
""" Delete an attribute of a directed vertex """
v0 = DirectedVertex(val='v0', attrs={'city': 'Modena', 0: 1})
v0.del_attr('city')
self.assertEqual(v0.attrs, {0: 1})
v0.del_attr(0)
self.assertEqual(v0.attrs, {})
