Mercurial > repos > shellac > sam_consensus_v3
diff env/lib/python3.9/site-packages/networkx/algorithms/tree/tests/test_coding.py @ 0:4f3585e2f14b draft default tip
"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
author | shellac |
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date | Mon, 22 Mar 2021 18:12:50 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.9/site-packages/networkx/algorithms/tree/tests/test_coding.py Mon Mar 22 18:12:50 2021 +0000 @@ -0,0 +1,117 @@ +"""Unit tests for the :mod:`~networkx.algorithms.tree.coding` module.""" +from itertools import product + +import pytest +import networkx as nx +from networkx.testing import assert_nodes_equal +from networkx.testing import assert_edges_equal + + +class TestPruferSequence: + """Unit tests for the Prüfer sequence encoding and decoding + functions. + + """ + + def test_nontree(self): + with pytest.raises(nx.NotATree): + G = nx.cycle_graph(3) + nx.to_prufer_sequence(G) + + def test_null_graph(self): + with pytest.raises(nx.NetworkXPointlessConcept): + nx.to_prufer_sequence(nx.null_graph()) + + def test_trivial_graph(self): + with pytest.raises(nx.NetworkXPointlessConcept): + nx.to_prufer_sequence(nx.trivial_graph()) + + def test_bad_integer_labels(self): + with pytest.raises(KeyError): + T = nx.Graph(nx.utils.pairwise("abc")) + nx.to_prufer_sequence(T) + + def test_encoding(self): + """Tests for encoding a tree as a Prüfer sequence using the + iterative strategy. + + """ + # Example from Wikipedia. + tree = nx.Graph([(0, 3), (1, 3), (2, 3), (3, 4), (4, 5)]) + sequence = nx.to_prufer_sequence(tree) + assert sequence == [3, 3, 3, 4] + + def test_decoding(self): + """Tests for decoding a tree from a Prüfer sequence.""" + # Example from Wikipedia. + sequence = [3, 3, 3, 4] + tree = nx.from_prufer_sequence(sequence) + assert_nodes_equal(list(tree), list(range(6))) + edges = [(0, 3), (1, 3), (2, 3), (3, 4), (4, 5)] + assert_edges_equal(list(tree.edges()), edges) + + def test_decoding2(self): + # Example from "An Optimal Algorithm for Prufer Codes". + sequence = [2, 4, 0, 1, 3, 3] + tree = nx.from_prufer_sequence(sequence) + assert_nodes_equal(list(tree), list(range(8))) + edges = [(0, 1), (0, 4), (1, 3), (2, 4), (2, 5), (3, 6), (3, 7)] + assert_edges_equal(list(tree.edges()), edges) + + def test_inverse(self): + """Tests that the encoding and decoding functions are inverses. + + """ + for T in nx.nonisomorphic_trees(4): + T2 = nx.from_prufer_sequence(nx.to_prufer_sequence(T)) + assert_nodes_equal(list(T), list(T2)) + assert_edges_equal(list(T.edges()), list(T2.edges())) + + for seq in product(range(4), repeat=2): + seq2 = nx.to_prufer_sequence(nx.from_prufer_sequence(seq)) + assert list(seq) == seq2 + + +class TestNestedTuple: + """Unit tests for the nested tuple encoding and decoding functions. + + """ + + def test_nontree(self): + with pytest.raises(nx.NotATree): + G = nx.cycle_graph(3) + nx.to_nested_tuple(G, 0) + + def test_unknown_root(self): + with pytest.raises(nx.NodeNotFound): + G = nx.path_graph(2) + nx.to_nested_tuple(G, "bogus") + + def test_encoding(self): + T = nx.full_rary_tree(2, 2 ** 3 - 1) + expected = (((), ()), ((), ())) + actual = nx.to_nested_tuple(T, 0) + assert_nodes_equal(expected, actual) + + def test_canonical_form(self): + T = nx.Graph() + T.add_edges_from([(0, 1), (0, 2), (0, 3)]) + T.add_edges_from([(1, 4), (1, 5)]) + T.add_edges_from([(3, 6), (3, 7)]) + root = 0 + actual = nx.to_nested_tuple(T, root, canonical_form=True) + expected = ((), ((), ()), ((), ())) + assert actual == expected + + def test_decoding(self): + balanced = (((), ()), ((), ())) + expected = nx.full_rary_tree(2, 2 ** 3 - 1) + actual = nx.from_nested_tuple(balanced) + assert nx.is_isomorphic(expected, actual) + + def test_sensible_relabeling(self): + balanced = (((), ()), ((), ())) + T = nx.from_nested_tuple(balanced, sensible_relabeling=True) + edges = [(0, 1), (0, 2), (1, 3), (1, 4), (2, 5), (2, 6)] + assert_nodes_equal(list(T), list(range(2 ** 3 - 1))) + assert_edges_equal(list(T.edges()), edges)