def test_remove_isolated_vertices(self) -> None:
g = Graph([(1, 2), (2, 3), (5, 5)])
g.remove_edge(1, 2, remove_semi_isolated_vertices=False)
g.add_vertex(4)
assert set(g.vertices()) == {g[1], g[2], g[3], g[4], g[5]}
g.remove_isolated_vertices(ignore_self_loops=False)
assert set(g.vertices()) == {
g[2],
g[3],
g[5],
}, "isolated vertices 1 and 4 should have been removed"
g.remove_isolated_vertices(ignore_self_loops=True)
assert set(g.vertices()) == {
g[2], g[3]
}, "semi-isolated vertex 5 should have been removed"
def test_vertices(self) -> None:
g = Graph([(1, 2), (2, 3), (3, 4)])
assert set(g.vertices()) == {
g[1],
g[2],
g[3],
g[4],
}, "graph should have vertices 1, 2, 3, 4"
def test_deepcopy(self) -> None:
g = Graph([(1, 2, {"color": "blue"}), (3, 4)])
g.add_vertex(42)
g_copy = g.deepcopy()
assert set(g.vertices()) == set(
g_copy.vertices()), "graph copy should have same vertices"
assert (
g[1] is not g_copy[1]
), "graph copy vertex objects should be distinct from original graph"
assert set(g.edges()) == set(
g_copy.edges()), "graph copy should have same edges"
assert g.get_edge(1, 2) is not g_copy.get_edge(
1, 2
), "graph copy edge objects should be distinct from original graph"
assert (
g.get_edge(1, 2)._attr == g_copy.get_edge(1, 2)._attr
), "graph copy edge object `_attr` dictionary should contain logically equal contents"
assert (
g.get_edge(1, 2)._attr is not g_copy.get_edge(1, 2)._attr
), "graph copy edge object `_attr` dictionary should be distinct from original graph"