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Diffstat (limited to '.venv/lib/python3.12/site-packages/networkx/classes/tests/test_graph.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/networkx/classes/tests/test_graph.py | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_graph.py b/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_graph.py new file mode 100644 index 00000000..b0048a31 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_graph.py @@ -0,0 +1,920 @@ +import gc +import pickle +import platform +import weakref + +import pytest + +import networkx as nx +from networkx.utils import edges_equal, graphs_equal, nodes_equal + + +class BaseGraphTester: + """Tests for data-structure independent graph class features.""" + + def test_contains(self): + G = self.K3 + assert 1 in G + assert 4 not in G + assert "b" not in G + assert [] not in G # no exception for nonhashable + assert {1: 1} not in G # no exception for nonhashable + + def test_order(self): + G = self.K3 + assert len(G) == 3 + assert G.order() == 3 + assert G.number_of_nodes() == 3 + + def test_nodes(self): + G = self.K3 + assert isinstance(G._node, G.node_dict_factory) + assert isinstance(G._adj, G.adjlist_outer_dict_factory) + assert all( + isinstance(adj, G.adjlist_inner_dict_factory) for adj in G._adj.values() + ) + assert sorted(G.nodes()) == self.k3nodes + assert sorted(G.nodes(data=True)) == [(0, {}), (1, {}), (2, {})] + + def test_none_node(self): + G = self.Graph() + with pytest.raises(ValueError): + G.add_node(None) + with pytest.raises(ValueError): + G.add_nodes_from([None]) + with pytest.raises(ValueError): + G.add_edge(0, None) + with pytest.raises(ValueError): + G.add_edges_from([(0, None)]) + + def test_has_node(self): + G = self.K3 + assert G.has_node(1) + assert not G.has_node(4) + assert not G.has_node([]) # no exception for nonhashable + assert not G.has_node({1: 1}) # no exception for nonhashable + + def test_has_edge(self): + G = self.K3 + assert G.has_edge(0, 1) + assert not G.has_edge(0, -1) + + def test_neighbors(self): + G = self.K3 + assert sorted(G.neighbors(0)) == [1, 2] + with pytest.raises(nx.NetworkXError): + G.neighbors(-1) + + @pytest.mark.skipif( + platform.python_implementation() == "PyPy", reason="PyPy gc is different" + ) + def test_memory_leak(self): + G = self.Graph() + + def count_objects_of_type(_type): + # Iterating over all objects tracked by gc can include weak references + # whose weakly-referenced objects may no longer exist. Calling `isinstance` + # on such a weak reference will raise ReferenceError. There are at least + # three workarounds for this: one is to compare type names instead of using + # `isinstance` such as `type(obj).__name__ == typename`, another is to use + # `type(obj) == _type`, and the last is to ignore ProxyTypes as we do below. + # NOTE: even if this safeguard is deemed unnecessary to pass NetworkX tests, + # we should still keep it for maximum safety for other NetworkX backends. + return sum( + 1 + for obj in gc.get_objects() + if not isinstance(obj, weakref.ProxyTypes) and isinstance(obj, _type) + ) + + gc.collect() + before = count_objects_of_type(self.Graph) + G.copy() + gc.collect() + after = count_objects_of_type(self.Graph) + assert before == after + + # test a subgraph of the base class + class MyGraph(self.Graph): + pass + + gc.collect() + G = MyGraph() + before = count_objects_of_type(MyGraph) + G.copy() + gc.collect() + after = count_objects_of_type(MyGraph) + assert before == after + + def test_edges(self): + G = self.K3 + assert isinstance(G._adj, G.adjlist_outer_dict_factory) + assert edges_equal(G.edges(), [(0, 1), (0, 2), (1, 2)]) + assert edges_equal(G.edges(0), [(0, 1), (0, 2)]) + assert edges_equal(G.edges([0, 1]), [(0, 1), (0, 2), (1, 2)]) + with pytest.raises(nx.NetworkXError): + G.edges(-1) + + def test_degree(self): + G = self.K3 + assert sorted(G.degree()) == [(0, 2), (1, 2), (2, 2)] + assert dict(G.degree()) == {0: 2, 1: 2, 2: 2} + assert G.degree(0) == 2 + with pytest.raises(nx.NetworkXError): + G.degree(-1) # node not in graph + + def test_size(self): + G = self.K3 + assert G.size() == 3 + assert G.number_of_edges() == 3 + + def test_nbunch_iter(self): + G = self.K3 + assert nodes_equal(G.nbunch_iter(), self.k3nodes) # all nodes + assert nodes_equal(G.nbunch_iter(0), [0]) # single node + assert nodes_equal(G.nbunch_iter([0, 1]), [0, 1]) # sequence + # sequence with none in graph + assert nodes_equal(G.nbunch_iter([-1]), []) + # string sequence with none in graph + assert nodes_equal(G.nbunch_iter("foo"), []) + # node not in graph doesn't get caught upon creation of iterator + bunch = G.nbunch_iter(-1) + # but gets caught when iterator used + with pytest.raises(nx.NetworkXError, match="is not a node or a sequence"): + list(bunch) + # unhashable doesn't get caught upon creation of iterator + bunch = G.nbunch_iter([0, 1, 2, {}]) + # but gets caught when iterator hits the unhashable + with pytest.raises( + nx.NetworkXError, match="in sequence nbunch is not a valid node" + ): + list(bunch) + + def test_nbunch_iter_node_format_raise(self): + # Tests that a node that would have failed string formatting + # doesn't cause an error when attempting to raise a + # :exc:`nx.NetworkXError`. + + # For more information, see pull request #1813. + G = self.Graph() + nbunch = [("x", set())] + with pytest.raises(nx.NetworkXError): + list(G.nbunch_iter(nbunch)) + + def test_selfloop_degree(self): + G = self.Graph() + G.add_edge(1, 1) + assert sorted(G.degree()) == [(1, 2)] + assert dict(G.degree()) == {1: 2} + assert G.degree(1) == 2 + assert sorted(G.degree([1])) == [(1, 2)] + assert G.degree(1, weight="weight") == 2 + + def test_selfloops(self): + G = self.K3.copy() + G.add_edge(0, 0) + assert nodes_equal(nx.nodes_with_selfloops(G), [0]) + assert edges_equal(nx.selfloop_edges(G), [(0, 0)]) + assert nx.number_of_selfloops(G) == 1 + G.remove_edge(0, 0) + G.add_edge(0, 0) + G.remove_edges_from([(0, 0)]) + G.add_edge(1, 1) + G.remove_node(1) + G.add_edge(0, 0) + G.add_edge(1, 1) + G.remove_nodes_from([0, 1]) + + def test_cache_reset(self): + G = self.K3.copy() + old_adj = G.adj + assert id(G.adj) == id(old_adj) + G._adj = {} + assert id(G.adj) != id(old_adj) + + old_nodes = G.nodes + assert id(G.nodes) == id(old_nodes) + G._node = {} + assert id(G.nodes) != id(old_nodes) + + def test_attributes_cached(self): + G = self.K3.copy() + assert id(G.nodes) == id(G.nodes) + assert id(G.edges) == id(G.edges) + assert id(G.degree) == id(G.degree) + assert id(G.adj) == id(G.adj) + + +class BaseAttrGraphTester(BaseGraphTester): + """Tests of graph class attribute features.""" + + def test_weighted_degree(self): + G = self.Graph() + G.add_edge(1, 2, weight=2, other=3) + G.add_edge(2, 3, weight=3, other=4) + assert sorted(d for n, d in G.degree(weight="weight")) == [2, 3, 5] + assert dict(G.degree(weight="weight")) == {1: 2, 2: 5, 3: 3} + assert G.degree(1, weight="weight") == 2 + assert nodes_equal((G.degree([1], weight="weight")), [(1, 2)]) + + assert nodes_equal((d for n, d in G.degree(weight="other")), [3, 7, 4]) + assert dict(G.degree(weight="other")) == {1: 3, 2: 7, 3: 4} + assert G.degree(1, weight="other") == 3 + assert edges_equal((G.degree([1], weight="other")), [(1, 3)]) + + def add_attributes(self, G): + G.graph["foo"] = [] + G.nodes[0]["foo"] = [] + G.remove_edge(1, 2) + ll = [] + G.add_edge(1, 2, foo=ll) + G.add_edge(2, 1, foo=ll) + + def test_name(self): + G = self.Graph(name="") + assert G.name == "" + G = self.Graph(name="test") + assert G.name == "test" + + def test_str_unnamed(self): + G = self.Graph() + G.add_edges_from([(1, 2), (2, 3)]) + assert str(G) == f"{type(G).__name__} with 3 nodes and 2 edges" + + def test_str_named(self): + G = self.Graph(name="foo") + G.add_edges_from([(1, 2), (2, 3)]) + assert str(G) == f"{type(G).__name__} named 'foo' with 3 nodes and 2 edges" + + def test_graph_chain(self): + G = self.Graph([(0, 1), (1, 2)]) + DG = G.to_directed(as_view=True) + SDG = DG.subgraph([0, 1]) + RSDG = SDG.reverse(copy=False) + assert G is DG._graph + assert DG is SDG._graph + assert SDG is RSDG._graph + + def test_copy(self): + G = self.Graph() + G.add_node(0) + G.add_edge(1, 2) + self.add_attributes(G) + # copy edge datadict but any container attr are same + H = G.copy() + self.graphs_equal(H, G) + self.different_attrdict(H, G) + self.shallow_copy_attrdict(H, G) + + def test_class_copy(self): + G = self.Graph() + G.add_node(0) + G.add_edge(1, 2) + self.add_attributes(G) + # copy edge datadict but any container attr are same + H = G.__class__(G) + self.graphs_equal(H, G) + self.different_attrdict(H, G) + self.shallow_copy_attrdict(H, G) + + def test_fresh_copy(self): + G = self.Graph() + G.add_node(0) + G.add_edge(1, 2) + self.add_attributes(G) + # copy graph structure but use fresh datadict + H = G.__class__() + H.add_nodes_from(G) + H.add_edges_from(G.edges()) + assert len(G.nodes[0]) == 1 + ddict = G.adj[1][2][0] if G.is_multigraph() else G.adj[1][2] + assert len(ddict) == 1 + assert len(H.nodes[0]) == 0 + ddict = H.adj[1][2][0] if H.is_multigraph() else H.adj[1][2] + assert len(ddict) == 0 + + def is_deepcopy(self, H, G): + self.graphs_equal(H, G) + self.different_attrdict(H, G) + self.deep_copy_attrdict(H, G) + + def deep_copy_attrdict(self, H, G): + self.deepcopy_graph_attr(H, G) + self.deepcopy_node_attr(H, G) + self.deepcopy_edge_attr(H, G) + + def deepcopy_graph_attr(self, H, G): + assert G.graph["foo"] == H.graph["foo"] + G.graph["foo"].append(1) + assert G.graph["foo"] != H.graph["foo"] + + def deepcopy_node_attr(self, H, G): + assert G.nodes[0]["foo"] == H.nodes[0]["foo"] + G.nodes[0]["foo"].append(1) + assert G.nodes[0]["foo"] != H.nodes[0]["foo"] + + def deepcopy_edge_attr(self, H, G): + assert G[1][2]["foo"] == H[1][2]["foo"] + G[1][2]["foo"].append(1) + assert G[1][2]["foo"] != H[1][2]["foo"] + + def is_shallow_copy(self, H, G): + self.graphs_equal(H, G) + self.shallow_copy_attrdict(H, G) + + def shallow_copy_attrdict(self, H, G): + self.shallow_copy_graph_attr(H, G) + self.shallow_copy_node_attr(H, G) + self.shallow_copy_edge_attr(H, G) + + def shallow_copy_graph_attr(self, H, G): + assert G.graph["foo"] == H.graph["foo"] + G.graph["foo"].append(1) + assert G.graph["foo"] == H.graph["foo"] + + def shallow_copy_node_attr(self, H, G): + assert G.nodes[0]["foo"] == H.nodes[0]["foo"] + G.nodes[0]["foo"].append(1) + assert G.nodes[0]["foo"] == H.nodes[0]["foo"] + + def shallow_copy_edge_attr(self, H, G): + assert G[1][2]["foo"] == H[1][2]["foo"] + G[1][2]["foo"].append(1) + assert G[1][2]["foo"] == H[1][2]["foo"] + + def same_attrdict(self, H, G): + old_foo = H[1][2]["foo"] + H.adj[1][2]["foo"] = "baz" + assert G.edges == H.edges + H.adj[1][2]["foo"] = old_foo + assert G.edges == H.edges + + old_foo = H.nodes[0]["foo"] + H.nodes[0]["foo"] = "baz" + assert G.nodes == H.nodes + H.nodes[0]["foo"] = old_foo + assert G.nodes == H.nodes + + def different_attrdict(self, H, G): + old_foo = H[1][2]["foo"] + H.adj[1][2]["foo"] = "baz" + assert G._adj != H._adj + H.adj[1][2]["foo"] = old_foo + assert G._adj == H._adj + + old_foo = H.nodes[0]["foo"] + H.nodes[0]["foo"] = "baz" + assert G._node != H._node + H.nodes[0]["foo"] = old_foo + assert G._node == H._node + + def graphs_equal(self, H, G): + assert G._adj == H._adj + assert G._node == H._node + assert G.graph == H.graph + assert G.name == H.name + if not G.is_directed() and not H.is_directed(): + assert H._adj[1][2] is H._adj[2][1] + assert G._adj[1][2] is G._adj[2][1] + else: # at least one is directed + if not G.is_directed(): + G._pred = G._adj + G._succ = G._adj + if not H.is_directed(): + H._pred = H._adj + H._succ = H._adj + assert G._pred == H._pred + assert G._succ == H._succ + assert H._succ[1][2] is H._pred[2][1] + assert G._succ[1][2] is G._pred[2][1] + + def test_graph_attr(self): + G = self.K3.copy() + G.graph["foo"] = "bar" + assert isinstance(G.graph, G.graph_attr_dict_factory) + assert G.graph["foo"] == "bar" + del G.graph["foo"] + assert G.graph == {} + H = self.Graph(foo="bar") + assert H.graph["foo"] == "bar" + + def test_node_attr(self): + G = self.K3.copy() + G.add_node(1, foo="bar") + assert all( + isinstance(d, G.node_attr_dict_factory) for u, d in G.nodes(data=True) + ) + assert nodes_equal(G.nodes(), [0, 1, 2]) + assert nodes_equal(G.nodes(data=True), [(0, {}), (1, {"foo": "bar"}), (2, {})]) + G.nodes[1]["foo"] = "baz" + assert nodes_equal(G.nodes(data=True), [(0, {}), (1, {"foo": "baz"}), (2, {})]) + assert nodes_equal(G.nodes(data="foo"), [(0, None), (1, "baz"), (2, None)]) + assert nodes_equal( + G.nodes(data="foo", default="bar"), [(0, "bar"), (1, "baz"), (2, "bar")] + ) + + def test_node_attr2(self): + G = self.K3.copy() + a = {"foo": "bar"} + G.add_node(3, **a) + assert nodes_equal(G.nodes(), [0, 1, 2, 3]) + assert nodes_equal( + G.nodes(data=True), [(0, {}), (1, {}), (2, {}), (3, {"foo": "bar"})] + ) + + def test_edge_lookup(self): + G = self.Graph() + G.add_edge(1, 2, foo="bar") + assert edges_equal(G.edges[1, 2], {"foo": "bar"}) + + def test_edge_attr(self): + G = self.Graph() + G.add_edge(1, 2, foo="bar") + assert all( + isinstance(d, G.edge_attr_dict_factory) for u, v, d in G.edges(data=True) + ) + assert edges_equal(G.edges(data=True), [(1, 2, {"foo": "bar"})]) + assert edges_equal(G.edges(data="foo"), [(1, 2, "bar")]) + + def test_edge_attr2(self): + G = self.Graph() + G.add_edges_from([(1, 2), (3, 4)], foo="foo") + assert edges_equal( + G.edges(data=True), [(1, 2, {"foo": "foo"}), (3, 4, {"foo": "foo"})] + ) + assert edges_equal(G.edges(data="foo"), [(1, 2, "foo"), (3, 4, "foo")]) + + def test_edge_attr3(self): + G = self.Graph() + G.add_edges_from([(1, 2, {"weight": 32}), (3, 4, {"weight": 64})], foo="foo") + assert edges_equal( + G.edges(data=True), + [ + (1, 2, {"foo": "foo", "weight": 32}), + (3, 4, {"foo": "foo", "weight": 64}), + ], + ) + + G.remove_edges_from([(1, 2), (3, 4)]) + G.add_edge(1, 2, data=7, spam="bar", bar="foo") + assert edges_equal( + G.edges(data=True), [(1, 2, {"data": 7, "spam": "bar", "bar": "foo"})] + ) + + def test_edge_attr4(self): + G = self.Graph() + G.add_edge(1, 2, data=7, spam="bar", bar="foo") + assert edges_equal( + G.edges(data=True), [(1, 2, {"data": 7, "spam": "bar", "bar": "foo"})] + ) + G[1][2]["data"] = 10 # OK to set data like this + assert edges_equal( + G.edges(data=True), [(1, 2, {"data": 10, "spam": "bar", "bar": "foo"})] + ) + + G.adj[1][2]["data"] = 20 + assert edges_equal( + G.edges(data=True), [(1, 2, {"data": 20, "spam": "bar", "bar": "foo"})] + ) + G.edges[1, 2]["data"] = 21 # another spelling, "edge" + assert edges_equal( + G.edges(data=True), [(1, 2, {"data": 21, "spam": "bar", "bar": "foo"})] + ) + G.adj[1][2]["listdata"] = [20, 200] + G.adj[1][2]["weight"] = 20 + dd = { + "data": 21, + "spam": "bar", + "bar": "foo", + "listdata": [20, 200], + "weight": 20, + } + assert edges_equal(G.edges(data=True), [(1, 2, dd)]) + + def test_to_undirected(self): + G = self.K3 + self.add_attributes(G) + H = nx.Graph(G) + self.is_shallow_copy(H, G) + self.different_attrdict(H, G) + H = G.to_undirected() + self.is_deepcopy(H, G) + + def test_to_directed_as_view(self): + H = nx.path_graph(2, create_using=self.Graph) + H2 = H.to_directed(as_view=True) + assert H is H2._graph + assert H2.has_edge(0, 1) + assert H2.has_edge(1, 0) or H.is_directed() + pytest.raises(nx.NetworkXError, H2.add_node, -1) + pytest.raises(nx.NetworkXError, H2.add_edge, 1, 2) + H.add_edge(1, 2) + assert H2.has_edge(1, 2) + assert H2.has_edge(2, 1) or H.is_directed() + + def test_to_undirected_as_view(self): + H = nx.path_graph(2, create_using=self.Graph) + H2 = H.to_undirected(as_view=True) + assert H is H2._graph + assert H2.has_edge(0, 1) + assert H2.has_edge(1, 0) + pytest.raises(nx.NetworkXError, H2.add_node, -1) + pytest.raises(nx.NetworkXError, H2.add_edge, 1, 2) + H.add_edge(1, 2) + assert H2.has_edge(1, 2) + assert H2.has_edge(2, 1) + + def test_directed_class(self): + G = self.Graph() + + class newGraph(G.to_undirected_class()): + def to_directed_class(self): + return newDiGraph + + def to_undirected_class(self): + return newGraph + + class newDiGraph(G.to_directed_class()): + def to_directed_class(self): + return newDiGraph + + def to_undirected_class(self): + return newGraph + + G = newDiGraph() if G.is_directed() else newGraph() + H = G.to_directed() + assert isinstance(H, newDiGraph) + H = G.to_undirected() + assert isinstance(H, newGraph) + + def test_to_directed(self): + G = self.K3 + self.add_attributes(G) + H = nx.DiGraph(G) + self.is_shallow_copy(H, G) + self.different_attrdict(H, G) + H = G.to_directed() + self.is_deepcopy(H, G) + + def test_subgraph(self): + G = self.K3 + self.add_attributes(G) + H = G.subgraph([0, 1, 2, 5]) + self.graphs_equal(H, G) + self.same_attrdict(H, G) + self.shallow_copy_attrdict(H, G) + + H = G.subgraph(0) + assert H.adj == {0: {}} + H = G.subgraph([]) + assert H.adj == {} + assert G.adj != {} + + def test_selfloops_attr(self): + G = self.K3.copy() + G.add_edge(0, 0) + G.add_edge(1, 1, weight=2) + assert edges_equal( + nx.selfloop_edges(G, data=True), [(0, 0, {}), (1, 1, {"weight": 2})] + ) + assert edges_equal( + nx.selfloop_edges(G, data="weight"), [(0, 0, None), (1, 1, 2)] + ) + + +class TestGraph(BaseAttrGraphTester): + """Tests specific to dict-of-dict-of-dict graph data structure""" + + def setup_method(self): + self.Graph = nx.Graph + # build dict-of-dict-of-dict K3 + ed1, ed2, ed3 = ({}, {}, {}) + self.k3adj = {0: {1: ed1, 2: ed2}, 1: {0: ed1, 2: ed3}, 2: {0: ed2, 1: ed3}} + self.k3edges = [(0, 1), (0, 2), (1, 2)] + self.k3nodes = [0, 1, 2] + self.K3 = self.Graph() + self.K3._adj = self.k3adj + self.K3._node = {} + self.K3._node[0] = {} + self.K3._node[1] = {} + self.K3._node[2] = {} + + def test_pickle(self): + G = self.K3 + pg = pickle.loads(pickle.dumps(G, -1)) + self.graphs_equal(pg, G) + pg = pickle.loads(pickle.dumps(G)) + self.graphs_equal(pg, G) + + def test_data_input(self): + G = self.Graph({1: [2], 2: [1]}, name="test") + assert G.name == "test" + assert sorted(G.adj.items()) == [(1, {2: {}}), (2, {1: {}})] + + def test_adjacency(self): + G = self.K3 + assert dict(G.adjacency()) == { + 0: {1: {}, 2: {}}, + 1: {0: {}, 2: {}}, + 2: {0: {}, 1: {}}, + } + + def test_getitem(self): + G = self.K3 + assert G.adj[0] == {1: {}, 2: {}} + assert G[0] == {1: {}, 2: {}} + with pytest.raises(KeyError): + G.__getitem__("j") + with pytest.raises(TypeError): + G.__getitem__(["A"]) + + def test_add_node(self): + G = self.Graph() + G.add_node(0) + assert G.adj == {0: {}} + # test add attributes + G.add_node(1, c="red") + G.add_node(2, c="blue") + G.add_node(3, c="red") + assert G.nodes[1]["c"] == "red" + assert G.nodes[2]["c"] == "blue" + assert G.nodes[3]["c"] == "red" + # test updating attributes + G.add_node(1, c="blue") + G.add_node(2, c="red") + G.add_node(3, c="blue") + assert G.nodes[1]["c"] == "blue" + assert G.nodes[2]["c"] == "red" + assert G.nodes[3]["c"] == "blue" + + def test_add_nodes_from(self): + G = self.Graph() + G.add_nodes_from([0, 1, 2]) + assert G.adj == {0: {}, 1: {}, 2: {}} + # test add attributes + G.add_nodes_from([0, 1, 2], c="red") + assert G.nodes[0]["c"] == "red" + assert G.nodes[2]["c"] == "red" + # test that attribute dicts are not the same + assert G.nodes[0] is not G.nodes[1] + # test updating attributes + G.add_nodes_from([0, 1, 2], c="blue") + assert G.nodes[0]["c"] == "blue" + assert G.nodes[2]["c"] == "blue" + assert G.nodes[0] is not G.nodes[1] + # test tuple input + H = self.Graph() + H.add_nodes_from(G.nodes(data=True)) + assert H.nodes[0]["c"] == "blue" + assert H.nodes[2]["c"] == "blue" + assert H.nodes[0] is not H.nodes[1] + # specific overrides general + H.add_nodes_from([0, (1, {"c": "green"}), (3, {"c": "cyan"})], c="red") + assert H.nodes[0]["c"] == "red" + assert H.nodes[1]["c"] == "green" + assert H.nodes[2]["c"] == "blue" + assert H.nodes[3]["c"] == "cyan" + + def test_remove_node(self): + G = self.K3.copy() + G.remove_node(0) + assert G.adj == {1: {2: {}}, 2: {1: {}}} + with pytest.raises(nx.NetworkXError): + G.remove_node(-1) + + # generator here to implement list,set,string... + + def test_remove_nodes_from(self): + G = self.K3.copy() + G.remove_nodes_from([0, 1]) + assert G.adj == {2: {}} + G.remove_nodes_from([-1]) # silent fail + + def test_add_edge(self): + G = self.Graph() + G.add_edge(0, 1) + assert G.adj == {0: {1: {}}, 1: {0: {}}} + G = self.Graph() + G.add_edge(*(0, 1)) + assert G.adj == {0: {1: {}}, 1: {0: {}}} + G = self.Graph() + with pytest.raises(ValueError): + G.add_edge(None, "anything") + + def test_add_edges_from(self): + G = self.Graph() + G.add_edges_from([(0, 1), (0, 2, {"weight": 3})]) + assert G.adj == { + 0: {1: {}, 2: {"weight": 3}}, + 1: {0: {}}, + 2: {0: {"weight": 3}}, + } + G = self.Graph() + G.add_edges_from([(0, 1), (0, 2, {"weight": 3}), (1, 2, {"data": 4})], data=2) + assert G.adj == { + 0: {1: {"data": 2}, 2: {"weight": 3, "data": 2}}, + 1: {0: {"data": 2}, 2: {"data": 4}}, + 2: {0: {"weight": 3, "data": 2}, 1: {"data": 4}}, + } + + with pytest.raises(nx.NetworkXError): + G.add_edges_from([(0,)]) # too few in tuple + with pytest.raises(nx.NetworkXError): + G.add_edges_from([(0, 1, 2, 3)]) # too many in tuple + with pytest.raises(TypeError): + G.add_edges_from([0]) # not a tuple + with pytest.raises(ValueError): + G.add_edges_from([(None, 3), (3, 2)]) # None cannot be a node + + def test_remove_edge(self): + G = self.K3.copy() + G.remove_edge(0, 1) + assert G.adj == {0: {2: {}}, 1: {2: {}}, 2: {0: {}, 1: {}}} + with pytest.raises(nx.NetworkXError): + G.remove_edge(-1, 0) + + def test_remove_edges_from(self): + G = self.K3.copy() + G.remove_edges_from([(0, 1)]) + assert G.adj == {0: {2: {}}, 1: {2: {}}, 2: {0: {}, 1: {}}} + G.remove_edges_from([(0, 0)]) # silent fail + + def test_clear(self): + G = self.K3.copy() + G.graph["name"] = "K3" + G.clear() + assert list(G.nodes) == [] + assert G.adj == {} + assert G.graph == {} + + def test_clear_edges(self): + G = self.K3.copy() + G.graph["name"] = "K3" + nodes = list(G.nodes) + G.clear_edges() + assert list(G.nodes) == nodes + assert G.adj == {0: {}, 1: {}, 2: {}} + assert list(G.edges) == [] + assert G.graph["name"] == "K3" + + def test_edges_data(self): + G = self.K3 + all_edges = [(0, 1, {}), (0, 2, {}), (1, 2, {})] + assert edges_equal(G.edges(data=True), all_edges) + assert edges_equal(G.edges(0, data=True), [(0, 1, {}), (0, 2, {})]) + assert edges_equal(G.edges([0, 1], data=True), all_edges) + with pytest.raises(nx.NetworkXError): + G.edges(-1, True) + + def test_get_edge_data(self): + G = self.K3.copy() + assert G.get_edge_data(0, 1) == {} + assert G[0][1] == {} + assert G.get_edge_data(10, 20) is None + assert G.get_edge_data(-1, 0) is None + assert G.get_edge_data(-1, 0, default=1) == 1 + + def test_update(self): + # specify both edges and nodes + G = self.K3.copy() + G.update(nodes=[3, (4, {"size": 2})], edges=[(4, 5), (6, 7, {"weight": 2})]) + nlist = [ + (0, {}), + (1, {}), + (2, {}), + (3, {}), + (4, {"size": 2}), + (5, {}), + (6, {}), + (7, {}), + ] + assert sorted(G.nodes.data()) == nlist + if G.is_directed(): + elist = [ + (0, 1, {}), + (0, 2, {}), + (1, 0, {}), + (1, 2, {}), + (2, 0, {}), + (2, 1, {}), + (4, 5, {}), + (6, 7, {"weight": 2}), + ] + else: + elist = [ + (0, 1, {}), + (0, 2, {}), + (1, 2, {}), + (4, 5, {}), + (6, 7, {"weight": 2}), + ] + assert sorted(G.edges.data()) == elist + assert G.graph == {} + + # no keywords -- order is edges, nodes + G = self.K3.copy() + G.update([(4, 5), (6, 7, {"weight": 2})], [3, (4, {"size": 2})]) + assert sorted(G.nodes.data()) == nlist + assert sorted(G.edges.data()) == elist + assert G.graph == {} + + # update using only a graph + G = self.Graph() + G.graph["foo"] = "bar" + G.add_node(2, data=4) + G.add_edge(0, 1, weight=0.5) + GG = G.copy() + H = self.Graph() + GG.update(H) + assert graphs_equal(G, GG) + H.update(G) + assert graphs_equal(H, G) + + # update nodes only + H = self.Graph() + H.update(nodes=[3, 4]) + assert H.nodes ^ {3, 4} == set() + assert H.size() == 0 + + # update edges only + H = self.Graph() + H.update(edges=[(3, 4)]) + assert sorted(H.edges.data()) == [(3, 4, {})] + assert H.size() == 1 + + # No inputs -> exception + with pytest.raises(nx.NetworkXError): + nx.Graph().update() + + +class TestEdgeSubgraph: + """Unit tests for the :meth:`Graph.edge_subgraph` method.""" + + def setup_method(self): + # Create a path graph on five nodes. + G = nx.path_graph(5) + # Add some node, edge, and graph attributes. + for i in range(5): + G.nodes[i]["name"] = f"node{i}" + G.edges[0, 1]["name"] = "edge01" + G.edges[3, 4]["name"] = "edge34" + G.graph["name"] = "graph" + # Get the subgraph induced by the first and last edges. + self.G = G + self.H = G.edge_subgraph([(0, 1), (3, 4)]) + + def test_correct_nodes(self): + """Tests that the subgraph has the correct nodes.""" + assert [0, 1, 3, 4] == sorted(self.H.nodes()) + + def test_correct_edges(self): + """Tests that the subgraph has the correct edges.""" + assert [(0, 1, "edge01"), (3, 4, "edge34")] == sorted(self.H.edges(data="name")) + + def test_add_node(self): + """Tests that adding a node to the original graph does not + affect the nodes of the subgraph. + + """ + self.G.add_node(5) + assert [0, 1, 3, 4] == sorted(self.H.nodes()) + + def test_remove_node(self): + """Tests that removing a node in the original graph does + affect the nodes of the subgraph. + + """ + self.G.remove_node(0) + assert [1, 3, 4] == sorted(self.H.nodes()) + + def test_node_attr_dict(self): + """Tests that the node attribute dictionary of the two graphs is + the same object. + + """ + for v in self.H: + assert self.G.nodes[v] == self.H.nodes[v] + # Making a change to G should make a change in H and vice versa. + self.G.nodes[0]["name"] = "foo" + assert self.G.nodes[0] == self.H.nodes[0] + self.H.nodes[1]["name"] = "bar" + assert self.G.nodes[1] == self.H.nodes[1] + + def test_edge_attr_dict(self): + """Tests that the edge attribute dictionary of the two graphs is + the same object. + + """ + for u, v in self.H.edges(): + assert self.G.edges[u, v] == self.H.edges[u, v] + # Making a change to G should make a change in H and vice versa. + self.G.edges[0, 1]["name"] = "foo" + assert self.G.edges[0, 1]["name"] == self.H.edges[0, 1]["name"] + self.H.edges[3, 4]["name"] = "bar" + assert self.G.edges[3, 4]["name"] == self.H.edges[3, 4]["name"] + + def test_graph_attr_dict(self): + """Tests that the graph attribute dictionary of the two graphs + is the same object. + + """ + assert self.G.graph is self.H.graph |