File: //lib/python3/dist-packages/networkx/classes/tests/test_graph.py
import pickle
import gc
import networkx as nx
from networkx.testing.utils import *
import pytest
class BaseGraphTester(object):
""" 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 sorted(G.nodes()) == self.k3nodes
assert sorted(G.nodes(data=True)) == [(0, {}), (1, {}), (2, {})]
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) == True
assert G.has_edge(0, -1) == False
def test_neighbors(self):
G = self.K3
assert sorted(G.neighbors(0)) == [1, 2]
with pytest.raises(nx.NetworkXError):
G.neighbors(-1)
def test_memory_leak(self):
G = self.Graph()
def count_objects_of_type(_type):
return sum(1 for obj in gc.get_objects() if isinstance(obj, _type))
gc.collect()
before = count_objects_of_type(self.Graph)
G.copy()
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()
after = count_objects_of_type(MyGraph)
assert before == after
def test_edges(self):
G = self.K3
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_weighted_degree(self):
G = self.Graph()
G.add_edge(1, 2, weight=2)
G.add_edge(2, 3, weight=3)
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 G.degree([1], weight='weight') == [(1, 2)]
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):
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):
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])
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.__str__() == "test"
assert G.name == "test"
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
G.graph['foo'] = 'bar'
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
G.add_node(1, foo='bar')
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
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_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(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: {}})]
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[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
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
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: {}}}
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
def test_remove_edge(self):
G = self.K3
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
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
G.clear()
assert G.adj == {}
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
assert G.get_edge_data(0, 1) == {}
assert G[0][1] == {}
assert G.get_edge_data(10, 20) == None
assert G.get_edge_data(-1, 0) == None
assert G.get_edge_data(-1, 0, default=1) == 1
def test_update(self):
# specify both edgees 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(object):
"""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'] = 'node{}'.format(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