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_issubclass_and_isinstance(self) -> None:
g = MultiDiGraph()
v1 = g.add_vertex(1)
assert isinstance(
v1, vertex_module.VertexBase
), "v1 should be an instance of superclass VertexBase"
assert isinstance(
v1, MultiDiVertex), "v1 should be a MultiDiVertex instance"
assert issubclass(MultiDiVertex, vertex_module.VertexBase
), "MultiDiVertex should be VertexBase subclass"
def test_issubclass_and_isinstance(self) -> None:
g = MultiDiGraph()
edge: MultiDiEdge = g.add_edge(1, 2)
assert isinstance(
edge, edge_module.MultiEdgeBase
), "edge should be an instance of superclass MultiEdgeBase"
assert isinstance(
edge, MultiDiEdge), "edge should be an MultiDiEdge instance"
assert issubclass(MultiDiEdge, edge_module.MultiEdgeBase
), "MultiDiEdge should be MultiEdgeBase subclass"
def test_repr_str_and_label(self) -> None:
mdg = MultiDiGraph([(2, 1), (2, 1)])
assert mdg.get_edge(
2,
1).label == "(2, 1)", "directed multiedge label should be (2, 1)"
assert (mdg.get_edge(2, 1).__str__() == mdg.get_edge(
2, 1).__repr__()), "edge __repr__ should equal __str__"
assert (mdg.get_edge(2, 1).__str__() == "(2, 1), (2, 1)"
), "__str__ should be '(2, 1), (2, 1)'"
mdg.add_edge(3, 4, weight=1.5)
assert mdg.get_edge(
2,
1).label == "(2, 1)", "directed multiedge label should be (2, 1)"
assert (
mdg.get_edge(2, 1).__str__() == "(2, 1, 1.0), (2, 1, 1.0)"
), "edge __str__ should be '(2, 1, 1.0), (2, 1, 1.0)' after adding weighted edge to graph"
def test_degree(self) -> None:
g = MultiDiGraph([(1, 1), (1, 1), (2, 3), (2, 3)])
assert g[
1].degree == 4, "vertex with two self loops should have degree 4"
assert g[
1].indegree == 2, "vertex with two loops should have indegree 2"
assert g[
1].outdegree == 2, "vertex with two loops should have outdegree 2"
assert g[2].outdegree == 2, "vertex 2 should have outdegree 2"
assert g[2].indegree == 0, "vertex 2 should have indegree 0"
assert g[3].indegree == 2, "vertex 3 should have indegree 2"
def test_is_vertex_type(self) -> None:
g = Graph()
v: Vertex = g.add_vertex(1)
assert vertex_module.is_vertex_type(
v), "Vertex object should be a VertexType"
g2 = DiGraph()
di_v: DiVertex = g2.add_vertex(1)
assert vertex_module.is_vertex_type(
di_v), "DiVertex object should be a VertexType"
g3 = MultiGraph()
multi_v: MultiVertex = g3.add_vertex(1)
assert vertex_module.is_vertex_type(
multi_v), "MultiVertex object should be a VertexType"
g4 = MultiDiGraph()
multi_di_v: MultiDiVertex = g4.add_vertex(1)
assert vertex_module.is_vertex_type(
multi_di_v), "MultiDiVertex should be a VertexType"
assert vertex_module.is_vertex_type(
10), "int vertex label should be a VertexType"
assert vertex_module.is_vertex_type(
"s"), "str vertex label should be a VertexType"
assert vertex_module.is_vertex_type(("s", {
"color": "blue"
})), "vertex tuple should be a VertexType"
assert not vertex_module.is_vertex_type(
10.99), "float should not be a VertexType"
assert not vertex_module.is_vertex_type(
("s", "t")), "edge tuple should not be a VertexType"
assert not vertex_module.is_vertex_type(
("s", "t",
4.5)), "edge tuple with edge weight should not be a VertexType"
g.add_edge("s", "t")
assert not vertex_module.is_vertex_type(g.get_edge(
"s", "t")), "edge object should not be a VertexType"
def test_loop_edge(self) -> None:
g = MultiDiGraph()
g.add_vertex(0)
assert not g[0].loop_edge, "vertex 0 should not have a loop edge"
g.add_edge(1, 1)
g.add_edge(1, 1)
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 g[
1].loop_edge.multiplicity == 2, "vertex 1 should have two loops"
def test_incident_edges(self) -> None:
g = MultiDiGraph([(1, 1), (1, 1), (2, 3), (2, 3)])
assert g[1].incident_edges() == {g.get_edge(
1, 1)}, "vertex 1 should be incident on (1, 1)"
assert g[1].incident_edges_incoming() == {g.get_edge(
1, 1)}, "incoming edge should be (1, 1)"
assert g[1].incident_edges_outgoing() == {g.get_edge(
1, 1)}, "outgoing edge should be (1, 1)"
assert g[2].incident_edges_outgoing() == {g.get_edge(
2, 3)}, "outgoing edges should (2, 3)"
assert not g[2].incident_edges_incoming(
), "should be no incoming edges"
def test_adj_vertices(self) -> None:
g = MultiDiGraph([(1, 1), (1, 1), (2, 3), (2, 3)])
assert g[1].adj_vertices() == {
g[1]
}, "vertex with directed self-loop should be adjacent to itself"
assert g[1].adj_vertices_incoming() == {
g[1]
}, "vertex with directed self-loop should connect to itself via an incoming edge"
assert g[1].adj_vertices_outgoing() == {
g[1]
}, "vertex with directed self-loop should connect to itself via an outgoing edge"
assert g[2].adj_vertices() == {
g[3]
}, "vertex 2 should be adjacent to vertex 3"
assert not g[2].adj_vertices_incoming(
), "vertex 2 should have no incoming adjacent vertices"
assert g[2].adj_vertices_outgoing() == {
g[3]
}, "vertex 2 should have vertex 3 as outgoing adjacent vertex"
def test_equality_operator(self) -> None:
mdg = MultiDiGraph([(1, 2), (2, 1), (3, 4), (3, 4, 1.5),
(6, 7, 9.5, {
"k": "v1"
})])
mdg2 = MultiDiGraph([(2, 1), (2, 1), (3, 4), (3, 4, 5.5),
(6, 7, 9.5, {
"k": "v2"
})])
assert mdg.get_edge(1, 2) != mdg2.get_edge(
2, 1), "multiedges (1, 2) and (2, 1) should not be equal"
assert mdg.get_edge(2, 1) != mdg2.get_edge(
2, 1
), "multiedges (2, 1) should not be equal due to different multiplicities)"
assert mdg.get_edge(3, 4) != mdg2.get_edge(
3, 4
), "multiedges (3, 4) should not be equal due to different weights"
assert mdg.get_edge(6, 7) == mdg2.get_edge(
6, 7
), "multiedges (6, 7) should be equal (attributes of parallel connections not checked)"