def test_contract(self) -> None:
g = MultiGraph([(1, 2), (1, 3), (2, 3), (2, 4), (2, 2), (2, 2)])
assert g[1].adj_vertices() == {
g[2],
g[3],
}, "vertex 1 should be adjacent to vertices 2 and 3"
assert (
g.get_edge(1, 3).multiplicity == 1
), "before edge contraction, edge (1, 3) should have multiplicity 1"
assert g.get_edge(
2, 2).multiplicity == 2, "vertex 2 should have two loops"
g.get_edge(1, 2).contract(remove_loops=False)
assert g[1].adj_vertices() == {
g[1],
g[3],
g[4],
}, "after edge contraction, vertex 1 should be adjacent to vertices 1, 3, and 4"
assert (
g.get_edge(1, 3).multiplicity == 2
), "after edge contraction, edge (1, 3) should have multiplicity 2"
assert g[1].loop_edge, "vertex 1 should have loop edge (1, 1)"
print(f"\nDEBUG: g[1].loop_edge => {g[1].loop_edge}\n")
assert g[
1].loop_edge.multiplicity == 3, "loop edge should have multiplicity 3"
assert not g.has_vertex(
2), "after edge contraction, vertex 2 should be removed"
g2 = MultiDiGraph([(1, 2), (2, 4), (2, 2), (2, 2)])
g2.get_edge(1, 2).contract(remove_loops=True)
assert not g2[
1].loop_edge, "loop edge should be removed after edge contraction"
def test_edgeview(self) -> None:
mg = MultiGraph([(1, 1), (1, 1), (3, 2), (2, 3)])
loops: MultiEdge = mg.get_edge(1, 1)
loop_view: EdgeConnectionView[MultiVertex,
MultiEdge] = loops.connections()[0]
assert loop_view.is_loop(), "edge connection should be a loop"
assert loop_view.label == "(1, 1)", "label should be '(1, 1)'"
assert (str(loop_view) == "EdgeConnectionView(1, 1)"
), "__str__() should return '<class name><connection label>'"
assert loop_view.vertex1 == 1, "vertex1 should have label 1"
assert loop_view.vertex2 == 1, "vertex2 should have label 1"
assert loop_view.weight == edge_module.DEFAULT_WEIGHT, "edge should have default weight"
assert not loop_view.has_attributes_dict(
), "edge attr dict should not be instantiated"
loop_view["color"] = "blue"
assert loop_view[
"color"] == "blue", "connection should have 'color' attribute"
assert loop_view.attr[
"color"] == "blue", "connection should have 'color' attribute"
assert (
loop_view.has_attributes_dict()
), "edge attr dictionary should be instantiated after using property accessor"
with pytest.raises(KeyError):
_ = loop_view["unknown_key"]
multiedge = mg.get_edge(2, 3)
view = multiedge.connections()[0]
assert view.vertex1 == mg[3], "vertex1 should be vertex 2"
assert view.vertex2 == mg[2], "vertex2 should be vertex 3"
assert view.label == "(2, 3)", "label should be '(2, 3)'"
def test_loop(self) -> None:
g = MultiGraph([(1, 1), (1, 1)])
assert g.get_edge(
1, 1).is_loop(), "edge (1, 1) should self identify as a loop"
assert g.get_edge(1, 1).vertex1 == 1, "loop edge vertex1 should be 1"
assert g.get_edge(1, 1).vertex2 == 1, "loop edge vertex2 should be 1"
assert (g.get_edge(1, 1).multiplicity == 2
), "there should be two parallel loop edge connections"
def test_weight(self) -> None:
g = MultiGraph([(1, 2), (1, 2), (3, 4, 9.5), (3, 4, 0.5)])
assert (
g.get_edge(1, 2).weight == 2 * edge_module.DEFAULT_WEIGHT
), "each parallel connection should default to edge_module.DEFAULT_WEIGHT"
assert (g.get_edge(3, 4).weight == 10.0
), "multiedge weight should be cumulative of all connections"
assert (
g.get_edge(1,
2).connections()[0].weight == edge_module.DEFAULT_WEIGHT
), "Individual connections should default to edge_module.DEFAULT_WEIGHT"
def test_connections_and_connection_items(self) -> None:
g = MultiGraph([(1, 2), (1, 2), (2, 2), (2, 2), (2, 2)])
c12 = list(g.get_edge(1, 2).connections())
assert len(c12) == 2, "edge (1, 2) should have 2 connections"
keys = set()
for key, connection in g.get_edge(2, 2).connection_items():
assert not connection.has_attributes_dict(
), "loop connection should not have attr dict"
keys.add(key)
assert len(
keys) == 3, "edge (2, 2) should have 3 parallel loop connections"
def test_remove(self) -> None:
g = MultiGraph([(1, 2), (1, 2), (2, 3)])
assert g.has_edge(1,
2), "prior to removal, graph should have edge (1, 2)"
assert not g[1].is_isolated(
), "vertex 1 should not be isolated prior to edge removal"
g.get_edge(1, 2).remove(remove_semi_isolated_vertices=False)
assert not g.has_edge(
1, 2), "after removal, graph should not have edge (1, 2)"
assert g.has_vertex(
1
), "after edge removal, isolated vertex 1 should still be in graph"
assert g[1].is_isolated(
), "vertex 1 should be isolated after edge removal"
g2 = MultiGraph([(1, 2), (1, 2), (1, 1), (1, 1), (2, 3)])
g2.get_edge(1, 2).remove(remove_semi_isolated_vertices=True)
assert not g2.has_vertex(
1
), "after edge removal, semi-isolated vertex 1 should have been removed"
def test_incident_edges_and_loop_edge(self) -> None:
g = MultiGraph()
g.add_vertex(0)
assert not g[0].loop_edge, "vertex 0 should not have a loop edge"
g.add_edges_from([(1, 1), (1, 1), (2, 3), (2, 3)])
assert g[1].incident_edges() == {g.get_edge(
1, 1)}, "vertex 1 should have self loop as incident edge"
assert g[1].loop_edge, "vertex 1 should have a self loop"
assert len(g[2].incident_edges()
) == 1, "vertex 2 should have one incident multiedge"
assert (next(iter(g[2].incident_edges())).multiplicity == 2
), "multiedge (2, 3) should have multiplicity 2"
def test_add_remove_get_connection(self) -> None:
g = MultiGraph([(1, 2)])
assert g.get_edge(
1, 2).multiplicity == 1, "edge (1, 2) should have multiplicity 1"
g.get_edge(1, 2).add_connection(weight=3.5,
key="connection2",
color="blue")
assert (
g.get_edge(1, 2).multiplicity == 2
), "edge (1, 2) should have multiplicity 2 after adding parallel connection"
connection = g.get_edge(1, 2).get_connection("connection2")
assert connection[
"color"] == "blue", "new connection should have color attribute 'blue'"
assert connection.weight == 3.5, "new connection should have weight 3.5"
g.get_edge(1, 2).remove_connection("connection2")
assert (
g.get_edge(1, 2).multiplicity == 1
), "edge (1, 2) should have multiplicity 1 after removing parallel connection"
def test_repr_str_and_label(self) -> None:
mg = MultiGraph([(2, 1), (1, 2)])
assert mg.get_edge(
2, 1).label == "(1, 2)", "multiedge label should be (1, 2)"
assert (mg.get_edge(2, 1).__str__() == mg.get_edge(
2, 1).__repr__()), "edge __repr__ should equal __str__"
assert (mg.get_edge(2, 1).__str__() == "(1, 2), (1, 2)"
), "edge __str__ should be '(1, 2), (1, 2)'"
mg.add_edge(3, 4, weight=1.5)
assert mg.get_edge(
2, 1).label == "(1, 2)", "multiedge label should be (1, 2)"
assert (
mg.get_edge(2, 1).__str__() == "(1, 2, 1.0), (1, 2, 1.0)"
), "edge __str__ should be '(1, 2, 1.0), (1, 2, 1.0)' after adding weighted edge to graph"
def test_equality_operator(self) -> None:
mg = MultiGraph([(1, 2), (2, 1), (3, 4), (3, 4, 1.5),
(6, 7, 9.5, {
"k": "v1"
})])
mg2 = MultiGraph([(2, 1), (2, 1), (3, 4), (3, 4, 5.5),
(6, 7, 9.5, {
"k": "v2"
})])
assert mg.get_edge(1, 2) == mg2.get_edge(
2, 1), "multiedges (1, 2) should be equal"
assert mg.get_edge(3, 4) != mg2.get_edge(
3, 4
), "multiedges (3, 4) should not be equal due to different weights"
assert mg.get_edge(6, 7) == mg2.get_edge(
6, 7
), "multiedges (6, 7) should be equal (attributes of parallel connections not checked)"
def test_parse_edge_type(self) -> None:
g = Graph()
g.add_edge(1, 2)
edge_data1 = pp_module.parse_edge_type(g.get_edge(1, 2))
assert edge_data1.vertex1.label == "1"
assert edge_data1.vertex2.label == "2"
mg = MultiGraph([(3, 4), (3, 4)])
edge_data2 = pp_module.parse_edge_type(mg.get_edge(3, 4))
assert edge_data2.vertex1.label == "3"
assert edge_data2.vertex2.label == "4"
edge_tuple = (1, 2)
edge_data3 = pp_module.parse_edge_type(edge_tuple)
assert edge_data3.vertex1.label == "1"
assert edge_data3.vertex2.label == "2"
edge_tuple_weighted = (3, 4, 3.5)
edge_data4 = pp_module.parse_edge_type(edge_tuple_weighted)
assert edge_data4.vertex1.label == "3"
assert edge_data4.vertex2.label == "4"
assert edge_data4.weight == 3.5
edge_tuple_attr = (4, 5, {"color": "blue"})
edge_data5 = pp_module.parse_edge_type(edge_tuple_attr)
assert edge_data5.vertex1.label == "4"
assert edge_data5.vertex2.label == "5"
assert edge_data5.weight == edge_module.DEFAULT_WEIGHT
assert edge_data5.attr["color"] == "blue"
edge_tuple_weighted_attr = (6, 7, 9.5, {"k": "v"})
edge_data6 = pp_module.parse_edge_type(edge_tuple_weighted_attr)
assert edge_data6.vertex1.label == "6"
assert edge_data6.vertex2.label == "7"
assert edge_data6.weight == 9.5
assert edge_data6.attr["k"] == "v"
def test_vertex1_vertex2(self) -> None:
g = MultiGraph([(2, 1), (1, 2)])
assert g.get_edge(
1, 2).multiplicity == 2, "multiedge should have multiplicity 2"
assert g.get_edge(1, 2).vertex1 == 2, "vertex1 should be 2"
assert g.get_edge(1, 2).vertex2 == 1, "vertex2 should be 1"