"""
Unit tests for edgelists.
"""
import io
import textwrap
import pytest
import networkx as nx
from networkx.utils import edges_equal, graphs_equal, nodes_equal
edges_no_data = textwrap.dedent(
"""
# comment line
1 2
# comment line
2 3
"""
)
edges_with_values = textwrap.dedent(
"""
# comment line
1 2 2.0
# comment line
2 3 3.0
"""
)
edges_with_weight = textwrap.dedent(
"""
# comment line
1 2 {'weight':2.0}
# comment line
2 3 {'weight':3.0}
"""
)
edges_with_multiple_attrs = textwrap.dedent(
"""
# comment line
1 2 {'weight':2.0, 'color':'green'}
# comment line
2 3 {'weight':3.0, 'color':'red'}
"""
)
edges_with_multiple_attrs_csv = textwrap.dedent(
"""
# comment line
1, 2, {'weight':2.0, 'color':'green'}
# comment line
2, 3, {'weight':3.0, 'color':'red'}
"""
)
_expected_edges_weights = [(1, 2, {"weight": 2.0}), (2, 3, {"weight": 3.0})]
_expected_edges_multiattr = [
(1, 2, {"weight": 2.0, "color": "green"}),
(2, 3, {"weight": 3.0, "color": "red"}),
]
@pytest.mark.parametrize(
("data", "extra_kwargs"),
(
(edges_no_data, {}),
(edges_with_values, {}),
(edges_with_weight, {}),
(edges_with_multiple_attrs, {}),
(edges_with_multiple_attrs_csv, {"delimiter": ","}),
),
)
def test_read_edgelist_no_data(data, extra_kwargs):
bytesIO = io.BytesIO(data.encode("utf-8"))
G = nx.read_edgelist(bytesIO, nodetype=int, data=False, **extra_kwargs)
assert edges_equal(G.edges(), [(1, 2), (2, 3)])
def test_read_weighted_edgelist():
bytesIO = io.BytesIO(edges_with_values.encode("utf-8"))
G = nx.read_weighted_edgelist(bytesIO, nodetype=int)
assert edges_equal(G.edges(data=True), _expected_edges_weights)
@pytest.mark.parametrize(
("data", "extra_kwargs", "expected"),
(
(edges_with_weight, {}, _expected_edges_weights),
(edges_with_multiple_attrs, {}, _expected_edges_multiattr),
(edges_with_multiple_attrs_csv, {"delimiter": ","}, _expected_edges_multiattr),
),
)
def test_read_edgelist_with_data(data, extra_kwargs, expected):
bytesIO = io.BytesIO(data.encode("utf-8"))
G = nx.read_edgelist(bytesIO, nodetype=int, **extra_kwargs)
assert edges_equal(G.edges(data=True), expected)
@pytest.fixture
def example_graph():
G = nx.Graph()
G.add_weighted_edges_from([(1, 2, 3.0), (2, 3, 27.0), (3, 4, 3.0)])
return G
def test_parse_edgelist_no_data(example_graph):
G = example_graph
H = nx.parse_edgelist(["1 2", "2 3", "3 4"], nodetype=int)
assert nodes_equal(G.nodes, H.nodes)
assert edges_equal(G.edges, H.edges)
def test_parse_edgelist_with_data_dict(example_graph):
G = example_graph
H = nx.parse_edgelist(
["1 2 {'weight': 3}", "2 3 {'weight': 27}", "3 4 {'weight': 3.0}"], nodetype=int
)
assert nodes_equal(G.nodes, H.nodes)
assert edges_equal(G.edges(data=True), H.edges(data=True))
def test_parse_edgelist_with_data_list(example_graph):
G = example_graph
H = nx.parse_edgelist(
["1 2 3", "2 3 27", "3 4 3.0"], nodetype=int, data=(("weight", float),)
)
assert nodes_equal(G.nodes, H.nodes)
assert edges_equal(G.edges(data=True), H.edges(data=True))
def test_parse_edgelist():
# ignore lines with less than 2 nodes
lines = ["1;2", "2 3", "3 4"]
G = nx.parse_edgelist(lines, nodetype=int)
assert list(G.edges()) == [(2, 3), (3, 4)]
# unknown nodetype
with pytest.raises(TypeError, match="Failed to convert nodes"):
lines = ["1 2", "2 3", "3 4"]
nx.parse_edgelist(lines, nodetype="nope")
# lines have invalid edge format
with pytest.raises(TypeError, match="Failed to convert edge data"):
lines = ["1 2 3", "2 3", "3 4"]
nx.parse_edgelist(lines, nodetype=int)
# edge data and data_keys not the same length
with pytest.raises(IndexError, match="not the same length"):
lines = ["1 2 3", "2 3 27", "3 4 3.0"]
nx.parse_edgelist(
lines, nodetype=int, data=(("weight", float), ("capacity", int))
)
# edge data can't be converted to edge type
with pytest.raises(TypeError, match="Failed to convert"):
lines = ["1 2 't1'", "2 3 't3'", "3 4 't3'"]
nx.parse_edgelist(lines, nodetype=int, data=(("weight", float),))
def test_comments_None():
edgelist = ["node#1 node#2", "node#2 node#3"]
# comments=None supported to ignore all comment characters
G = nx.parse_edgelist(edgelist, comments=None)
H = nx.Graph([e.split(" ") for e in edgelist])
assert edges_equal(G.edges, H.edges)
class TestEdgelist:
@classmethod
def setup_class(cls):
cls.G = nx.Graph(name="test")
e = [("a", "b"), ("b", "c"), ("c", "d"), ("d", "e"), ("e", "f"), ("a", "f")]
cls.G.add_edges_from(e)
cls.G.add_node("g")
cls.DG = nx.DiGraph(cls.G)
cls.XG = nx.MultiGraph()
cls.XG.add_weighted_edges_from([(1, 2, 5), (1, 2, 5), (1, 2, 1), (3, 3, 42)])
cls.XDG = nx.MultiDiGraph(cls.XG)
def test_write_edgelist_1(self):
fh = io.BytesIO()
G = nx.Graph()
G.add_edges_from([(1, 2), (2, 3)])
nx.write_edgelist(G, fh, data=False)
fh.seek(0)
assert fh.read() == b"1 2\n2 3\n"
def test_write_edgelist_2(self):
fh = io.BytesIO()
G = nx.Graph()
G.add_edges_from([(1, 2), (2, 3)])
nx.write_edgelist(G, fh, data=True)
fh.seek(0)
assert fh.read() == b"1 2 {}\n2 3 {}\n"
def test_write_edgelist_3(self):
fh = io.BytesIO()
G = nx.Graph()
G.add_edge(1, 2, weight=2.0)
G.add_edge(2, 3, weight=3.0)
nx.write_edgelist(G, fh, data=True)
fh.seek(0)
assert fh.read() == b"1 2 {'weight': 2.0}\n2 3 {'weight': 3.0}\n"
def test_write_edgelist_4(self):
fh = io.BytesIO()
G = nx.Graph()
G.add_edge(1, 2, weight=2.0)
G.add_edge(2, 3, weight=3.0)
nx.write_edgelist(G, fh, data=[("weight")])
fh.seek(0)
assert fh.read() == b"1 2 2.0\n2 3 3.0\n"
def test_unicode(self, tmp_path):
G = nx.Graph()
name1 = chr(2344) + chr(123) + chr(6543)
name2 = chr(5543) + chr(1543) + chr(324)
G.add_edge(name1, "Radiohead", **{name2: 3})
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname)
assert graphs_equal(G, H)
def test_latin1_issue(self, tmp_path):
G = nx.Graph()
name1 = chr(2344) + chr(123) + chr(6543)
name2 = chr(5543) + chr(1543) + chr(324)
G.add_edge(name1, "Radiohead", **{name2: 3})
fname = tmp_path / "el.txt"
with pytest.raises(UnicodeEncodeError):
nx.write_edgelist(G, fname, encoding="latin-1")
def test_latin1(self, tmp_path):
G = nx.Graph()
name1 = "Bj" + chr(246) + "rk"
name2 = chr(220) + "ber"
G.add_edge(name1, "Radiohead", **{name2: 3})
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname, encoding="latin-1")
H = nx.read_edgelist(fname, encoding="latin-1")
assert graphs_equal(G, H)
def test_edgelist_graph(self, tmp_path):
G = self.G
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname)
H2 = nx.read_edgelist(fname)
assert H is not H2 # they should be different graphs
G.remove_node("g") # isolated nodes are not written in edgelist
assert nodes_equal(list(H), list(G))
assert edges_equal(list(H.edges()), list(G.edges()))
def test_edgelist_digraph(self, tmp_path):
G = self.DG
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname, create_using=nx.DiGraph())
H2 = nx.read_edgelist(fname, create_using=nx.DiGraph())
assert H is not H2 # they should be different graphs
G.remove_node("g") # isolated nodes are not written in edgelist
assert nodes_equal(list(H), list(G))
assert edges_equal(list(H.edges()), list(G.edges()))
def test_edgelist_integers(self, tmp_path):
G = nx.convert_node_labels_to_integers(self.G)
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname, nodetype=int)
# isolated nodes are not written in edgelist
G.remove_nodes_from(list(nx.isolates(G)))
assert nodes_equal(list(H), list(G))
assert edges_equal(list(H.edges()), list(G.edges()))
def test_edgelist_multigraph(self, tmp_path):
G = self.XG
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname, nodetype=int, create_using=nx.MultiGraph())
H2 = nx.read_edgelist(fname, nodetype=int, create_using=nx.MultiGraph())
assert H is not H2 # they should be different graphs
assert nodes_equal(list(H), list(G))
assert edges_equal(list(H.edges()), list(G.edges()))
def test_edgelist_multidigraph(self, tmp_path):
G = self.XDG
fname = tmp_path / "el.txt"
nx.write_edgelist(G, fname)
H = nx.read_edgelist(fname, nodetype=int, create_using=nx.MultiDiGraph())
H2 = nx.read_edgelist(fname, nodetype=int, create_using=nx.MultiDiGraph())
assert H is not H2 # they should be different graphs
assert nodes_equal(list(H), list(G))
assert edges_equal(list(H.edges()), list(G.edges()))
def test_edgelist_consistent_strip_handling():
"""See gh-7462
Input when printed looks like::
1 2 3
2 3
3 4 3.0
Note the trailing \\t after the `3` in the second row, indicating an empty
data value.
"""
s = io.StringIO("1\t2\t3\n2\t3\t\n3\t4\t3.0")
G = nx.parse_edgelist(s, delimiter="\t", nodetype=int, data=[("value", str)])
assert sorted(G.edges(data="value")) == [(1, 2, "3"), (2, 3, ""), (3, 4, "3.0")]
