two version of R2R are hereHEADmaster

1 files changed, 1035 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_function.py b/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_function.py
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+++ b/.venv/lib/python3.12/site-packages/networkx/classes/tests/test_function.py
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+import random
+
+import pytest
+
+import networkx as nx
+from networkx.utils import edges_equal, nodes_equal
+
+
+def test_degree_histogram_empty():
+    G = nx.Graph()
+    assert nx.degree_histogram(G) == []
+
+
+class TestFunction:
+    def setup_method(self):
+        self.G = nx.Graph({0: [1, 2, 3], 1: [1, 2, 0], 4: []}, name="Test")
+        self.Gdegree = {0: 3, 1: 2, 2: 2, 3: 1, 4: 0}
+        self.Gnodes = list(range(5))
+        self.Gedges = [(0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2)]
+        self.DG = nx.DiGraph({0: [1, 2, 3], 1: [1, 2, 0], 4: []})
+        self.DGin_degree = {0: 1, 1: 2, 2: 2, 3: 1, 4: 0}
+        self.DGout_degree = {0: 3, 1: 3, 2: 0, 3: 0, 4: 0}
+        self.DGnodes = list(range(5))
+        self.DGedges = [(0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2)]
+
+    def test_nodes(self):
+        assert nodes_equal(self.G.nodes(), list(nx.nodes(self.G)))
+        assert nodes_equal(self.DG.nodes(), list(nx.nodes(self.DG)))
+
+    def test_edges(self):
+        assert edges_equal(self.G.edges(), list(nx.edges(self.G)))
+        assert sorted(self.DG.edges()) == sorted(nx.edges(self.DG))
+        assert edges_equal(
+            self.G.edges(nbunch=[0, 1, 3]), list(nx.edges(self.G, nbunch=[0, 1, 3]))
+        )
+        assert sorted(self.DG.edges(nbunch=[0, 1, 3])) == sorted(
+            nx.edges(self.DG, nbunch=[0, 1, 3])
+        )
+
+    def test_degree(self):
+        assert edges_equal(self.G.degree(), list(nx.degree(self.G)))
+        assert sorted(self.DG.degree()) == sorted(nx.degree(self.DG))
+        assert edges_equal(
+            self.G.degree(nbunch=[0, 1]), list(nx.degree(self.G, nbunch=[0, 1]))
+        )
+        assert sorted(self.DG.degree(nbunch=[0, 1])) == sorted(
+            nx.degree(self.DG, nbunch=[0, 1])
+        )
+        assert edges_equal(
+            self.G.degree(weight="weight"), list(nx.degree(self.G, weight="weight"))
+        )
+        assert sorted(self.DG.degree(weight="weight")) == sorted(
+            nx.degree(self.DG, weight="weight")
+        )
+
+    def test_neighbors(self):
+        assert list(self.G.neighbors(1)) == list(nx.neighbors(self.G, 1))
+        assert list(self.DG.neighbors(1)) == list(nx.neighbors(self.DG, 1))
+
+    def test_number_of_nodes(self):
+        assert self.G.number_of_nodes() == nx.number_of_nodes(self.G)
+        assert self.DG.number_of_nodes() == nx.number_of_nodes(self.DG)
+
+    def test_number_of_edges(self):
+        assert self.G.number_of_edges() == nx.number_of_edges(self.G)
+        assert self.DG.number_of_edges() == nx.number_of_edges(self.DG)
+
+    def test_is_directed(self):
+        assert self.G.is_directed() == nx.is_directed(self.G)
+        assert self.DG.is_directed() == nx.is_directed(self.DG)
+
+    def test_add_star(self):
+        G = self.G.copy()
+        nlist = [12, 13, 14, 15]
+        nx.add_star(G, nlist)
+        assert edges_equal(G.edges(nlist), [(12, 13), (12, 14), (12, 15)])
+
+        G = self.G.copy()
+        nx.add_star(G, nlist, weight=2.0)
+        assert edges_equal(
+            G.edges(nlist, data=True),
+            [
+                (12, 13, {"weight": 2.0}),
+                (12, 14, {"weight": 2.0}),
+                (12, 15, {"weight": 2.0}),
+            ],
+        )
+
+        G = self.G.copy()
+        nlist = [12]
+        nx.add_star(G, nlist)
+        assert nodes_equal(G, list(self.G) + nlist)
+
+        G = self.G.copy()
+        nlist = []
+        nx.add_star(G, nlist)
+        assert nodes_equal(G.nodes, self.Gnodes)
+        assert edges_equal(G.edges, self.G.edges)
+
+    def test_add_path(self):
+        G = self.G.copy()
+        nlist = [12, 13, 14, 15]
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges(nlist), [(12, 13), (13, 14), (14, 15)])
+        G = self.G.copy()
+        nx.add_path(G, nlist, weight=2.0)
+        assert edges_equal(
+            G.edges(nlist, data=True),
+            [
+                (12, 13, {"weight": 2.0}),
+                (13, 14, {"weight": 2.0}),
+                (14, 15, {"weight": 2.0}),
+            ],
+        )
+
+        G = self.G.copy()
+        nlist = ["node"]
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges(nlist), [])
+        assert nodes_equal(G, list(self.G) + ["node"])
+
+        G = self.G.copy()
+        nlist = iter(["node"])
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges(["node"]), [])
+        assert nodes_equal(G, list(self.G) + ["node"])
+
+        G = self.G.copy()
+        nlist = [12]
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges(nlist), [])
+        assert nodes_equal(G, list(self.G) + [12])
+
+        G = self.G.copy()
+        nlist = iter([12])
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges([12]), [])
+        assert nodes_equal(G, list(self.G) + [12])
+
+        G = self.G.copy()
+        nlist = []
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges, self.G.edges)
+        assert nodes_equal(G, list(self.G))
+
+        G = self.G.copy()
+        nlist = iter([])
+        nx.add_path(G, nlist)
+        assert edges_equal(G.edges, self.G.edges)
+        assert nodes_equal(G, list(self.G))
+
+    def test_add_cycle(self):
+        G = self.G.copy()
+        nlist = [12, 13, 14, 15]
+        oklists = [
+            [(12, 13), (12, 15), (13, 14), (14, 15)],
+            [(12, 13), (13, 14), (14, 15), (15, 12)],
+        ]
+        nx.add_cycle(G, nlist)
+        assert sorted(G.edges(nlist)) in oklists
+        G = self.G.copy()
+        oklists = [
+            [
+                (12, 13, {"weight": 1.0}),
+                (12, 15, {"weight": 1.0}),
+                (13, 14, {"weight": 1.0}),
+                (14, 15, {"weight": 1.0}),
+            ],
+            [
+                (12, 13, {"weight": 1.0}),
+                (13, 14, {"weight": 1.0}),
+                (14, 15, {"weight": 1.0}),
+                (15, 12, {"weight": 1.0}),
+            ],
+        ]
+        nx.add_cycle(G, nlist, weight=1.0)
+        assert sorted(G.edges(nlist, data=True)) in oklists
+
+        G = self.G.copy()
+        nlist = [12]
+        nx.add_cycle(G, nlist)
+        assert nodes_equal(G, list(self.G) + nlist)
+
+        G = self.G.copy()
+        nlist = []
+        nx.add_cycle(G, nlist)
+        assert nodes_equal(G.nodes, self.Gnodes)
+        assert edges_equal(G.edges, self.G.edges)
+
+    def test_subgraph(self):
+        assert (
+            self.G.subgraph([0, 1, 2, 4]).adj == nx.subgraph(self.G, [0, 1, 2, 4]).adj
+        )
+        assert (
+            self.DG.subgraph([0, 1, 2, 4]).adj == nx.subgraph(self.DG, [0, 1, 2, 4]).adj
+        )
+        assert (
+            self.G.subgraph([0, 1, 2, 4]).adj
+            == nx.induced_subgraph(self.G, [0, 1, 2, 4]).adj
+        )
+        assert (
+            self.DG.subgraph([0, 1, 2, 4]).adj
+            == nx.induced_subgraph(self.DG, [0, 1, 2, 4]).adj
+        )
+        # subgraph-subgraph chain is allowed in function interface
+        H = nx.induced_subgraph(self.G.subgraph([0, 1, 2, 4]), [0, 1, 4])
+        assert H._graph is not self.G
+        assert H.adj == self.G.subgraph([0, 1, 4]).adj
+
+    def test_edge_subgraph(self):
+        assert (
+            self.G.edge_subgraph([(1, 2), (0, 3)]).adj
+            == nx.edge_subgraph(self.G, [(1, 2), (0, 3)]).adj
+        )
+        assert (
+            self.DG.edge_subgraph([(1, 2), (0, 3)]).adj
+            == nx.edge_subgraph(self.DG, [(1, 2), (0, 3)]).adj
+        )
+
+    def test_create_empty_copy(self):
+        G = nx.create_empty_copy(self.G, with_data=False)
+        assert nodes_equal(G, list(self.G))
+        assert G.graph == {}
+        assert G._node == {}.fromkeys(self.G.nodes(), {})
+        assert G._adj == {}.fromkeys(self.G.nodes(), {})
+        G = nx.create_empty_copy(self.G)
+        assert nodes_equal(G, list(self.G))
+        assert G.graph == self.G.graph
+        assert G._node == self.G._node
+        assert G._adj == {}.fromkeys(self.G.nodes(), {})
+
+    def test_degree_histogram(self):
+        assert nx.degree_histogram(self.G) == [1, 1, 1, 1, 1]
+
+    def test_density(self):
+        assert nx.density(self.G) == 0.5
+        assert nx.density(self.DG) == 0.3
+        G = nx.Graph()
+        G.add_node(1)
+        assert nx.density(G) == 0.0
+
+    def test_density_selfloop(self):
+        G = nx.Graph()
+        G.add_edge(1, 1)
+        assert nx.density(G) == 0.0
+        G.add_edge(1, 2)
+        assert nx.density(G) == 2.0
+
+    def test_freeze(self):
+        G = nx.freeze(self.G)
+        assert G.frozen
+        pytest.raises(nx.NetworkXError, G.add_node, 1)
+        pytest.raises(nx.NetworkXError, G.add_nodes_from, [1])
+        pytest.raises(nx.NetworkXError, G.remove_node, 1)
+        pytest.raises(nx.NetworkXError, G.remove_nodes_from, [1])
+        pytest.raises(nx.NetworkXError, G.add_edge, 1, 2)
+        pytest.raises(nx.NetworkXError, G.add_edges_from, [(1, 2)])
+        pytest.raises(nx.NetworkXError, G.remove_edge, 1, 2)
+        pytest.raises(nx.NetworkXError, G.remove_edges_from, [(1, 2)])
+        pytest.raises(nx.NetworkXError, G.clear_edges)
+        pytest.raises(nx.NetworkXError, G.clear)
+
+    def test_is_frozen(self):
+        assert not nx.is_frozen(self.G)
+        G = nx.freeze(self.G)
+        assert G.frozen == nx.is_frozen(self.G)
+        assert G.frozen
+
+    def test_node_attributes_are_still_mutable_on_frozen_graph(self):
+        G = nx.freeze(nx.path_graph(3))
+        node = G.nodes[0]
+        node["node_attribute"] = True
+        assert node["node_attribute"] == True
+
+    def test_edge_attributes_are_still_mutable_on_frozen_graph(self):
+        G = nx.freeze(nx.path_graph(3))
+        edge = G.edges[(0, 1)]
+        edge["edge_attribute"] = True
+        assert edge["edge_attribute"] == True
+
+    def test_neighbors_complete_graph(self):
+        graph = nx.complete_graph(100)
+        pop = random.sample(list(graph), 1)
+        nbors = list(nx.neighbors(graph, pop[0]))
+        # should be all the other vertices in the graph
+        assert len(nbors) == len(graph) - 1
+
+        graph = nx.path_graph(100)
+        node = random.sample(list(graph), 1)[0]
+        nbors = list(nx.neighbors(graph, node))
+        # should be all the other vertices in the graph
+        if node != 0 and node != 99:
+            assert len(nbors) == 2
+        else:
+            assert len(nbors) == 1
+
+        # create a star graph with 99 outer nodes
+        graph = nx.star_graph(99)
+        nbors = list(nx.neighbors(graph, 0))
+        assert len(nbors) == 99
+
+    def test_non_neighbors(self):
+        graph = nx.complete_graph(100)
+        pop = random.sample(list(graph), 1)
+        nbors = nx.non_neighbors(graph, pop[0])
+        # should be all the other vertices in the graph
+        assert len(nbors) == 0
+
+        graph = nx.path_graph(100)
+        node = random.sample(list(graph), 1)[0]
+        nbors = nx.non_neighbors(graph, node)
+        # should be all the other vertices in the graph
+        if node != 0 and node != 99:
+            assert len(nbors) == 97
+        else:
+            assert len(nbors) == 98
+
+        # create a star graph with 99 outer nodes
+        graph = nx.star_graph(99)
+        nbors = nx.non_neighbors(graph, 0)
+        assert len(nbors) == 0
+
+        # disconnected graph
+        graph = nx.Graph()
+        graph.add_nodes_from(range(10))
+        nbors = nx.non_neighbors(graph, 0)
+        assert len(nbors) == 9
+
+    def test_non_edges(self):
+        # All possible edges exist
+        graph = nx.complete_graph(5)
+        nedges = list(nx.non_edges(graph))
+        assert len(nedges) == 0
+
+        graph = nx.path_graph(4)
+        expected = [(0, 2), (0, 3), (1, 3)]
+        nedges = list(nx.non_edges(graph))
+        for u, v in expected:
+            assert (u, v) in nedges or (v, u) in nedges
+
+        graph = nx.star_graph(4)
+        expected = [(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]
+        nedges = list(nx.non_edges(graph))
+        for u, v in expected:
+            assert (u, v) in nedges or (v, u) in nedges
+
+        # Directed graphs
+        graph = nx.DiGraph()
+        graph.add_edges_from([(0, 2), (2, 0), (2, 1)])
+        expected = [(0, 1), (1, 0), (1, 2)]
+        nedges = list(nx.non_edges(graph))
+        for e in expected:
+            assert e in nedges
+
+    def test_is_weighted(self):
+        G = nx.Graph()
+        assert not nx.is_weighted(G)
+
+        G = nx.path_graph(4)
+        assert not nx.is_weighted(G)
+        assert not nx.is_weighted(G, (2, 3))
+
+        G.add_node(4)
+        G.add_edge(3, 4, weight=4)
+        assert not nx.is_weighted(G)
+        assert nx.is_weighted(G, (3, 4))
+
+        G = nx.DiGraph()
+        G.add_weighted_edges_from(
+            [
+                ("0", "3", 3),
+                ("0", "1", -5),
+                ("1", "0", -5),
+                ("0", "2", 2),
+                ("1", "2", 4),
+                ("2", "3", 1),
+            ]
+        )
+        assert nx.is_weighted(G)
+        assert nx.is_weighted(G, ("1", "0"))
+
+        G = G.to_undirected()
+        assert nx.is_weighted(G)
+        assert nx.is_weighted(G, ("1", "0"))
+
+        pytest.raises(nx.NetworkXError, nx.is_weighted, G, (1, 2))
+
+    def test_is_negatively_weighted(self):
+        G = nx.Graph()
+        assert not nx.is_negatively_weighted(G)
+
+        G.add_node(1)
+        G.add_nodes_from([2, 3, 4, 5])
+        assert not nx.is_negatively_weighted(G)
+
+        G.add_edge(1, 2, weight=4)
+        assert not nx.is_negatively_weighted(G, (1, 2))
+
+        G.add_edges_from([(1, 3), (2, 4), (2, 6)])
+        G[1][3]["color"] = "blue"
+        assert not nx.is_negatively_weighted(G)
+        assert not nx.is_negatively_weighted(G, (1, 3))
+
+        G[2][4]["weight"] = -2
+        assert nx.is_negatively_weighted(G, (2, 4))
+        assert nx.is_negatively_weighted(G)
+
+        G = nx.DiGraph()
+        G.add_weighted_edges_from(
+            [
+                ("0", "3", 3),
+                ("0", "1", -5),
+                ("1", "0", -2),
+                ("0", "2", 2),
+                ("1", "2", -3),
+                ("2", "3", 1),
+            ]
+        )
+        assert nx.is_negatively_weighted(G)
+        assert not nx.is_negatively_weighted(G, ("0", "3"))
+        assert nx.is_negatively_weighted(G, ("1", "0"))
+
+        pytest.raises(nx.NetworkXError, nx.is_negatively_weighted, G, (1, 4))
+
+
+class TestCommonNeighbors:
+    @classmethod
+    def setup_class(cls):
+        cls.func = staticmethod(nx.common_neighbors)
+
+        def test_func(G, u, v, expected):
+            result = sorted(cls.func(G, u, v))
+            assert result == expected
+
+        cls.test = staticmethod(test_func)
+
+    def test_K5(self):
+        G = nx.complete_graph(5)
+        self.test(G, 0, 1, [2, 3, 4])
+
+    def test_P3(self):
+        G = nx.path_graph(3)
+        self.test(G, 0, 2, [1])
+
+    def test_S4(self):
+        G = nx.star_graph(4)
+        self.test(G, 1, 2, [0])
+
+    def test_digraph(self):
+        with pytest.raises(nx.NetworkXNotImplemented):
+            G = nx.DiGraph()
+            G.add_edges_from([(0, 1), (1, 2)])
+            self.func(G, 0, 2)
+
+    def test_nonexistent_nodes(self):
+        G = nx.complete_graph(5)
+        pytest.raises(nx.NetworkXError, nx.common_neighbors, G, 5, 4)
+        pytest.raises(nx.NetworkXError, nx.common_neighbors, G, 4, 5)
+        pytest.raises(nx.NetworkXError, nx.common_neighbors, G, 5, 6)
+
+    def test_custom1(self):
+        """Case of no common neighbors."""
+        G = nx.Graph()
+        G.add_nodes_from([0, 1])
+        self.test(G, 0, 1, [])
+
+    def test_custom2(self):
+        """Case of equal nodes."""
+        G = nx.complete_graph(4)
+        self.test(G, 0, 0, [1, 2, 3])
+
+
+@pytest.mark.parametrize(
+    "graph_type", (nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph)
+)
+def test_set_node_attributes(graph_type):
+    # Test single value
+    G = nx.path_graph(3, create_using=graph_type)
+    vals = 100
+    attr = "hello"
+    nx.set_node_attributes(G, vals, attr)
+    assert G.nodes[0][attr] == vals
+    assert G.nodes[1][attr] == vals
+    assert G.nodes[2][attr] == vals
+
+    # Test dictionary
+    G = nx.path_graph(3, create_using=graph_type)
+    vals = dict(zip(sorted(G.nodes()), range(len(G))))
+    attr = "hi"
+    nx.set_node_attributes(G, vals, attr)
+    assert G.nodes[0][attr] == 0
+    assert G.nodes[1][attr] == 1
+    assert G.nodes[2][attr] == 2
+
+    # Test dictionary of dictionaries
+    G = nx.path_graph(3, create_using=graph_type)
+    d = {"hi": 0, "hello": 200}
+    vals = dict.fromkeys(G.nodes(), d)
+    vals.pop(0)
+    nx.set_node_attributes(G, vals)
+    assert G.nodes[0] == {}
+    assert G.nodes[1]["hi"] == 0
+    assert G.nodes[2]["hello"] == 200
+
+
+@pytest.mark.parametrize(
+    ("values", "name"),
+    (
+        ({0: "red", 1: "blue"}, "color"),  # values dictionary
+        ({0: {"color": "red"}, 1: {"color": "blue"}}, None),  # dict-of-dict
+    ),
+)
+def test_set_node_attributes_ignores_extra_nodes(values, name):
+    """
+    When `values` is a dict or dict-of-dict keyed by nodes, ensure that keys
+    that correspond to nodes not in G are ignored.
+    """
+    G = nx.Graph()
+    G.add_node(0)
+    nx.set_node_attributes(G, values, name)
+    assert G.nodes[0]["color"] == "red"
+    assert 1 not in G.nodes
+
+
+@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph))
+def test_set_edge_attributes(graph_type):
+    # Test single value
+    G = nx.path_graph(3, create_using=graph_type)
+    attr = "hello"
+    vals = 3
+    nx.set_edge_attributes(G, vals, attr)
+    assert G[0][1][attr] == vals
+    assert G[1][2][attr] == vals
+
+    # Test multiple values
+    G = nx.path_graph(3, create_using=graph_type)
+    attr = "hi"
+    edges = [(0, 1), (1, 2)]
+    vals = dict(zip(edges, range(len(edges))))
+    nx.set_edge_attributes(G, vals, attr)
+    assert G[0][1][attr] == 0
+    assert G[1][2][attr] == 1
+
+    # Test dictionary of dictionaries
+    G = nx.path_graph(3, create_using=graph_type)
+    d = {"hi": 0, "hello": 200}
+    edges = [(0, 1)]
+    vals = dict.fromkeys(edges, d)
+    nx.set_edge_attributes(G, vals)
+    assert G[0][1]["hi"] == 0
+    assert G[0][1]["hello"] == 200
+    assert G[1][2] == {}
+
+
+@pytest.mark.parametrize(
+    ("values", "name"),
+    (
+        ({(0, 1): 1.0, (0, 2): 2.0}, "weight"),  # values dict
+        ({(0, 1): {"weight": 1.0}, (0, 2): {"weight": 2.0}}, None),  # values dod
+    ),
+)
+def test_set_edge_attributes_ignores_extra_edges(values, name):
+    """If `values` is a dict or dict-of-dicts containing edges that are not in
+    G, data associate with these edges should be ignored.
+    """
+    G = nx.Graph([(0, 1)])
+    nx.set_edge_attributes(G, values, name)
+    assert G[0][1]["weight"] == 1.0
+    assert (0, 2) not in G.edges
+
+
+@pytest.mark.parametrize("graph_type", (nx.MultiGraph, nx.MultiDiGraph))
+def test_set_edge_attributes_multi(graph_type):
+    # Test single value
+    G = nx.path_graph(3, create_using=graph_type)
+    attr = "hello"
+    vals = 3
+    nx.set_edge_attributes(G, vals, attr)
+    assert G[0][1][0][attr] == vals
+    assert G[1][2][0][attr] == vals
+
+    # Test multiple values
+    G = nx.path_graph(3, create_using=graph_type)
+    attr = "hi"
+    edges = [(0, 1, 0), (1, 2, 0)]
+    vals = dict(zip(edges, range(len(edges))))
+    nx.set_edge_attributes(G, vals, attr)
+    assert G[0][1][0][attr] == 0
+    assert G[1][2][0][attr] == 1
+
+    # Test dictionary of dictionaries
+    G = nx.path_graph(3, create_using=graph_type)
+    d = {"hi": 0, "hello": 200}
+    edges = [(0, 1, 0)]
+    vals = dict.fromkeys(edges, d)
+    nx.set_edge_attributes(G, vals)
+    assert G[0][1][0]["hi"] == 0
+    assert G[0][1][0]["hello"] == 200
+    assert G[1][2][0] == {}
+
+
+@pytest.mark.parametrize(
+    ("values", "name"),
+    (
+        ({(0, 1, 0): 1.0, (0, 2, 0): 2.0}, "weight"),  # values dict
+        ({(0, 1, 0): {"weight": 1.0}, (0, 2, 0): {"weight": 2.0}}, None),  # values dod
+    ),
+)
+def test_set_edge_attributes_multi_ignores_extra_edges(values, name):
+    """If `values` is a dict or dict-of-dicts containing edges that are not in
+    G, data associate with these edges should be ignored.
+    """
+    G = nx.MultiGraph([(0, 1, 0), (0, 1, 1)])
+    nx.set_edge_attributes(G, values, name)
+    assert G[0][1][0]["weight"] == 1.0
+    assert G[0][1][1] == {}
+    assert (0, 2) not in G.edges()
+
+
+def test_get_node_attributes():
+    graphs = [nx.Graph(), nx.DiGraph(), nx.MultiGraph(), nx.MultiDiGraph()]
+    for G in graphs:
+        G = nx.path_graph(3, create_using=G)
+        attr = "hello"
+        vals = 100
+        nx.set_node_attributes(G, vals, attr)
+        attrs = nx.get_node_attributes(G, attr)
+        assert attrs[0] == vals
+        assert attrs[1] == vals
+        assert attrs[2] == vals
+        default_val = 1
+        G.add_node(4)
+        attrs = nx.get_node_attributes(G, attr, default=default_val)
+        assert attrs[4] == default_val
+
+
+def test_get_edge_attributes():
+    graphs = [nx.Graph(), nx.DiGraph(), nx.MultiGraph(), nx.MultiDiGraph()]
+    for G in graphs:
+        G = nx.path_graph(3, create_using=G)
+        attr = "hello"
+        vals = 100
+        nx.set_edge_attributes(G, vals, attr)
+        attrs = nx.get_edge_attributes(G, attr)
+        assert len(attrs) == 2
+
+        for edge in G.edges:
+            assert attrs[edge] == vals
+
+        default_val = vals
+        G.add_edge(4, 5)
+        deafult_attrs = nx.get_edge_attributes(G, attr, default=default_val)
+        assert len(deafult_attrs) == 3
+
+        for edge in G.edges:
+            assert deafult_attrs[edge] == vals
+
+
+@pytest.mark.parametrize(
+    "graph_type", (nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph)
+)
+def test_remove_node_attributes(graph_type):
+    # Test removing single attribute
+    G = nx.path_graph(3, create_using=graph_type)
+    vals = 100
+    attr = "hello"
+    nx.set_node_attributes(G, vals, attr)
+    nx.remove_node_attributes(G, attr)
+    assert attr not in G.nodes[0]
+    assert attr not in G.nodes[1]
+    assert attr not in G.nodes[2]
+
+    # Test removing single attribute when multiple present
+    G = nx.path_graph(3, create_using=graph_type)
+    other_vals = 200
+    other_attr = "other"
+    nx.set_node_attributes(G, vals, attr)
+    nx.set_node_attributes(G, other_vals, other_attr)
+    nx.remove_node_attributes(G, attr)
+    assert attr not in G.nodes[0]
+    assert G.nodes[0][other_attr] == other_vals
+    assert attr not in G.nodes[1]
+    assert G.nodes[1][other_attr] == other_vals
+    assert attr not in G.nodes[2]
+    assert G.nodes[2][other_attr] == other_vals
+
+    # Test removing multiple attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_node_attributes(G, vals, attr)
+    nx.set_node_attributes(G, other_vals, other_attr)
+    nx.remove_node_attributes(G, attr, other_attr)
+    assert attr not in G.nodes[0] and other_attr not in G.nodes[0]
+    assert attr not in G.nodes[1] and other_attr not in G.nodes[1]
+    assert attr not in G.nodes[2] and other_attr not in G.nodes[2]
+
+    # Test removing multiple (but not all) attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    third_vals = 300
+    third_attr = "three"
+    nx.set_node_attributes(
+        G,
+        {
+            n: {attr: vals, other_attr: other_vals, third_attr: third_vals}
+            for n in G.nodes()
+        },
+    )
+    nx.remove_node_attributes(G, other_attr, third_attr)
+    assert other_attr not in G.nodes[0] and third_attr not in G.nodes[0]
+    assert other_attr not in G.nodes[1] and third_attr not in G.nodes[1]
+    assert other_attr not in G.nodes[2] and third_attr not in G.nodes[2]
+    assert G.nodes[0][attr] == vals
+    assert G.nodes[1][attr] == vals
+    assert G.nodes[2][attr] == vals
+
+    # Test incomplete node attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_node_attributes(
+        G,
+        {
+            1: {attr: vals, other_attr: other_vals},
+            2: {attr: vals, other_attr: other_vals},
+        },
+    )
+    nx.remove_node_attributes(G, attr)
+    assert attr not in G.nodes[0]
+    assert attr not in G.nodes[1]
+    assert attr not in G.nodes[2]
+    assert G.nodes[1][other_attr] == other_vals
+    assert G.nodes[2][other_attr] == other_vals
+
+    # Test removing on a subset of nodes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_node_attributes(
+        G,
+        {
+            n: {attr: vals, other_attr: other_vals, third_attr: third_vals}
+            for n in G.nodes()
+        },
+    )
+    nx.remove_node_attributes(G, attr, other_attr, nbunch=[0, 1])
+    assert attr not in G.nodes[0] and other_attr not in G.nodes[0]
+    assert attr not in G.nodes[1] and other_attr not in G.nodes[1]
+    assert attr in G.nodes[2] and other_attr in G.nodes[2]
+    assert third_attr in G.nodes[0] and G.nodes[0][third_attr] == third_vals
+    assert third_attr in G.nodes[1] and G.nodes[1][third_attr] == third_vals
+
+
+@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph))
+def test_remove_edge_attributes(graph_type):
+    # Test removing single attribute
+    G = nx.path_graph(3, create_using=graph_type)
+    attr = "hello"
+    vals = 100
+    nx.set_edge_attributes(G, vals, attr)
+    nx.remove_edge_attributes(G, attr)
+    assert len(nx.get_edge_attributes(G, attr)) == 0
+
+    # Test removing only some attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    other_attr = "other"
+    other_vals = 200
+    nx.set_edge_attributes(G, vals, attr)
+    nx.set_edge_attributes(G, other_vals, other_attr)
+    nx.remove_edge_attributes(G, attr)
+
+    assert attr not in G[0][1]
+    assert attr not in G[1][2]
+    assert G[0][1][other_attr] == 200
+    assert G[1][2][other_attr] == 200
+
+    # Test removing multiple attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_edge_attributes(G, vals, attr)
+    nx.set_edge_attributes(G, other_vals, other_attr)
+    nx.remove_edge_attributes(G, attr, other_attr)
+    assert attr not in G[0][1] and other_attr not in G[0][1]
+    assert attr not in G[1][2] and other_attr not in G[1][2]
+
+    # Test removing multiple (not all) attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    third_attr = "third"
+    third_vals = 300
+    nx.set_edge_attributes(
+        G,
+        {
+            (u, v): {attr: vals, other_attr: other_vals, third_attr: third_vals}
+            for u, v in G.edges()
+        },
+    )
+    nx.remove_edge_attributes(G, other_attr, third_attr)
+    assert other_attr not in G[0][1] and third_attr not in G[0][1]
+    assert other_attr not in G[1][2] and third_attr not in G[1][2]
+    assert G[0][1][attr] == vals
+    assert G[1][2][attr] == vals
+
+    # Test removing incomplete edge attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_edge_attributes(G, {(0, 1): {attr: vals, other_attr: other_vals}})
+    nx.remove_edge_attributes(G, other_attr)
+    assert other_attr not in G[0][1] and G[0][1][attr] == vals
+    assert other_attr not in G[1][2]
+
+    # Test removing subset of edge attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    nx.set_edge_attributes(
+        G,
+        {
+            (u, v): {attr: vals, other_attr: other_vals, third_attr: third_vals}
+            for u, v in G.edges()
+        },
+    )
+    nx.remove_edge_attributes(G, other_attr, third_attr, ebunch=[(0, 1)])
+    assert other_attr not in G[0][1] and third_attr not in G[0][1]
+    assert other_attr in G[1][2] and third_attr in G[1][2]
+
+
+@pytest.mark.parametrize("graph_type", (nx.MultiGraph, nx.MultiDiGraph))
+def test_remove_multi_edge_attributes(graph_type):
+    # Test removing single attribute
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    attr = "hello"
+    vals = 100
+    nx.set_edge_attributes(G, vals, attr)
+    nx.remove_edge_attributes(G, attr)
+    assert attr not in G[0][1][0]
+    assert attr not in G[1][2][0]
+    assert attr not in G[1][2][1]
+
+    # Test removing only some attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    other_attr = "other"
+    other_vals = 200
+    nx.set_edge_attributes(G, vals, attr)
+    nx.set_edge_attributes(G, other_vals, other_attr)
+    nx.remove_edge_attributes(G, attr)
+    assert attr not in G[0][1][0]
+    assert attr not in G[1][2][0]
+    assert attr not in G[1][2][1]
+    assert G[0][1][0][other_attr] == other_vals
+    assert G[1][2][0][other_attr] == other_vals
+    assert G[1][2][1][other_attr] == other_vals
+
+    # Test removing multiple attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    nx.set_edge_attributes(G, vals, attr)
+    nx.set_edge_attributes(G, other_vals, other_attr)
+    nx.remove_edge_attributes(G, attr, other_attr)
+    assert attr not in G[0][1][0] and other_attr not in G[0][1][0]
+    assert attr not in G[1][2][0] and other_attr not in G[1][2][0]
+    assert attr not in G[1][2][1] and other_attr not in G[1][2][1]
+
+    # Test removing multiple (not all) attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    third_attr = "third"
+    third_vals = 300
+    nx.set_edge_attributes(
+        G,
+        {
+            (u, v, k): {attr: vals, other_attr: other_vals, third_attr: third_vals}
+            for u, v, k in G.edges(keys=True)
+        },
+    )
+    nx.remove_edge_attributes(G, other_attr, third_attr)
+    assert other_attr not in G[0][1][0] and third_attr not in G[0][1][0]
+    assert other_attr not in G[1][2][0] and other_attr not in G[1][2][0]
+    assert other_attr not in G[1][2][1] and other_attr not in G[1][2][1]
+    assert G[0][1][0][attr] == vals
+    assert G[1][2][0][attr] == vals
+    assert G[1][2][1][attr] == vals
+
+    # Test removing incomplete edge attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    nx.set_edge_attributes(
+        G,
+        {
+            (0, 1, 0): {attr: vals, other_attr: other_vals},
+            (1, 2, 1): {attr: vals, other_attr: other_vals},
+        },
+    )
+    nx.remove_edge_attributes(G, other_attr)
+    assert other_attr not in G[0][1][0] and G[0][1][0][attr] == vals
+    assert other_attr not in G[1][2][0]
+    assert other_attr not in G[1][2][1]
+
+    # Test removing subset of edge attributes
+    G = nx.path_graph(3, create_using=graph_type)
+    G.add_edge(1, 2)
+    nx.set_edge_attributes(
+        G,
+        {
+            (0, 1, 0): {attr: vals, other_attr: other_vals},
+            (1, 2, 0): {attr: vals, other_attr: other_vals},
+            (1, 2, 1): {attr: vals, other_attr: other_vals},
+        },
+    )
+    nx.remove_edge_attributes(G, attr, ebunch=[(0, 1, 0), (1, 2, 0)])
+    assert attr not in G[0][1][0] and other_attr in G[0][1][0]
+    assert attr not in G[1][2][0] and other_attr in G[1][2][0]
+    assert attr in G[1][2][1] and other_attr in G[1][2][1]
+
+
+def test_is_empty():
+    graphs = [nx.Graph(), nx.DiGraph(), nx.MultiGraph(), nx.MultiDiGraph()]
+    for G in graphs:
+        assert nx.is_empty(G)
+        G.add_nodes_from(range(5))
+        assert nx.is_empty(G)
+        G.add_edges_from([(1, 2), (3, 4)])
+        assert not nx.is_empty(G)
+
+
+@pytest.mark.parametrize(
+    "graph_type", [nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph]
+)
+def test_selfloops(graph_type):
+    G = nx.complete_graph(3, create_using=graph_type)
+    G.add_edge(0, 0)
+    assert nodes_equal(nx.nodes_with_selfloops(G), [0])
+    assert edges_equal(nx.selfloop_edges(G), [(0, 0)])
+    assert edges_equal(nx.selfloop_edges(G, data=True), [(0, 0, {})])
+    assert nx.number_of_selfloops(G) == 1
+
+
+@pytest.mark.parametrize(
+    "graph_type", [nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph]
+)
+def test_selfloop_edges_attr(graph_type):
+    G = nx.complete_graph(3, create_using=graph_type)
+    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)])
+
+
+def test_selfloop_edges_multi_with_data_and_keys():
+    G = nx.complete_graph(3, create_using=nx.MultiGraph)
+    G.add_edge(0, 0, weight=10)
+    G.add_edge(0, 0, weight=100)
+    assert edges_equal(
+        nx.selfloop_edges(G, data="weight", keys=True), [(0, 0, 0, 10), (0, 0, 1, 100)]
+    )
+
+
+@pytest.mark.parametrize("graph_type", [nx.Graph, nx.DiGraph])
+def test_selfloops_removal(graph_type):
+    G = nx.complete_graph(3, create_using=graph_type)
+    G.add_edge(0, 0)
+    G.remove_edges_from(nx.selfloop_edges(G, keys=True))
+    G.add_edge(0, 0)
+    G.remove_edges_from(nx.selfloop_edges(G, data=True))
+    G.add_edge(0, 0)
+    G.remove_edges_from(nx.selfloop_edges(G, keys=True, data=True))
+
+
+@pytest.mark.parametrize("graph_type", [nx.MultiGraph, nx.MultiDiGraph])
+def test_selfloops_removal_multi(graph_type):
+    """test removing selfloops behavior vis-a-vis altering a dict while iterating.
+    cf. gh-4068"""
+    G = nx.complete_graph(3, create_using=graph_type)
+    # Defaults - see gh-4080
+    G.add_edge(0, 0)
+    G.add_edge(0, 0)
+    G.remove_edges_from(nx.selfloop_edges(G))
+    assert (0, 0) not in G.edges()
+    # With keys
+    G.add_edge(0, 0)
+    G.add_edge(0, 0)
+    with pytest.raises(RuntimeError):
+        G.remove_edges_from(nx.selfloop_edges(G, keys=True))
+    # With data
+    G.add_edge(0, 0)
+    G.add_edge(0, 0)
+    with pytest.raises(TypeError):
+        G.remove_edges_from(nx.selfloop_edges(G, data=True))
+    # With keys and data
+    G.add_edge(0, 0)
+    G.add_edge(0, 0)
+    with pytest.raises(RuntimeError):
+        G.remove_edges_from(nx.selfloop_edges(G, data=True, keys=True))
+
+
+def test_pathweight():
+    valid_path = [1, 2, 3]
+    invalid_path = [1, 3, 2]
+    graphs = [nx.Graph(), nx.DiGraph(), nx.MultiGraph(), nx.MultiDiGraph()]
+    edges = [
+        (1, 2, {"cost": 5, "dist": 6}),
+        (2, 3, {"cost": 3, "dist": 4}),
+        (1, 2, {"cost": 1, "dist": 2}),
+    ]
+    for graph in graphs:
+        graph.add_edges_from(edges)
+        assert nx.path_weight(graph, valid_path, "cost") == 4
+        assert nx.path_weight(graph, valid_path, "dist") == 6
+        pytest.raises(nx.NetworkXNoPath, nx.path_weight, graph, invalid_path, "cost")
+
+
+@pytest.mark.parametrize(
+    "G", (nx.Graph(), nx.DiGraph(), nx.MultiGraph(), nx.MultiDiGraph())
+)
+def test_ispath(G):
+    G.add_edges_from([(1, 2), (2, 3), (1, 2), (3, 4)])
+    valid_path = [1, 2, 3, 4]
+    invalid_path = [1, 2, 4, 3]  # wrong node order
+    another_invalid_path = [1, 2, 3, 4, 5]  # contains node not in G
+    assert nx.is_path(G, valid_path)
+    assert not nx.is_path(G, invalid_path)
+    assert not nx.is_path(G, another_invalid_path)
+
+
+@pytest.mark.parametrize("G", (nx.Graph(), nx.DiGraph()))
+def test_restricted_view(G):
+    G.add_edges_from([(0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2)])
+    G.add_node(4)
+    H = nx.restricted_view(G, [0, 2, 5], [(1, 2), (3, 4)])
+    assert set(H.nodes()) == {1, 3, 4}
+    assert set(H.edges()) == {(1, 1)}
+
+
+@pytest.mark.parametrize("G", (nx.MultiGraph(), nx.MultiDiGraph()))
+def test_restricted_view_multi(G):
+    G.add_edges_from(
+        [(0, 1, 0), (0, 2, 0), (0, 3, 0), (0, 1, 1), (1, 0, 0), (1, 1, 0), (1, 2, 0)]
+    )
+    G.add_node(4)
+    H = nx.restricted_view(G, [0, 2, 5], [(1, 2, 0), (3, 4, 0)])
+    assert set(H.nodes()) == {1, 3, 4}
+    assert set(H.edges()) == {(1, 1)}