# How to use stable_topological_sort method in tox

Best Python code snippet using tox_python

utils.py

Source:utils.py

`...11 if item_key < key(cur):12 coll.insert(idx, item)13 return14 coll.insert(len(coll), item)15def stable_topological_sort(items, partial_order):16 """Perform topological sort.17 items is a list or iterator of items to be sorted.18 partial_order is a list or iterator of pairs. If pair (a,b) is in it, it means19 that item a should appear before item b.20 Returns a list of the items in one of the possible orders, or raises21 LoopError if partial_order contains a loop.22 This is a stable sort so the relative order of the elements are kept.23 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c')]))24 ['a', 'b', 'c', 'd']25 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c'), ('b', 'c')]))26 ['a', 'b', 'c', 'd']27 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c'), ('b', 'c'), ('d', 'c')]))28 ['a', 'b', 'd', 'c']29 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c'), ('b', 'c'), ('d', 'c'), ('d', 'a')]))30 ['b', 'd', 'a', 'c']31 >>> list(stable_topological_sort(['b', 'a', 'c', 'd'], [('a', 'c'), ('b', 'c')]))32 ['b', 'a', 'c', 'd']33 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c'), ('b', 'c'), ('b', 'a')]))34 ['b', 'a', 'c', 'd']35 >>> list(stable_topological_sort(['a', 'b', 'c', 'd'], [('a', 'c'), ('b', 'c'), ('c', 'd'), ('d', 'a')]))36 Traceback (most recent call last):37 ...38 LoopError: Loop in DAG, cannot sort39 """40 graph = {}41 for idx, item in enumerate(items):42 if item not in graph:43 graph[item] = [0, idx]44 for a,b in partial_order:45 graph[a].append(b)46 graph[b][0] += 147 roots = [(node, info[1]) for (node, info) in graph.items() if info[0] == 0]48 roots.sort(key=lambda i: i[1])49 while roots:...`

test_graph.py

Source:test_graph.py

`...3from tox.util.graph import stable_topological_sort4def test_topological_order_specified_only():5 graph = OrderedDict()6 graph["A"] = "B", "C"7 result = stable_topological_sort(graph)8 assert result == ["A"]9def test_topological_order():10 graph = OrderedDict()11 graph["A"] = "B", "C"12 graph["B"] = ()13 graph["C"] = ()14 result = stable_topological_sort(graph)15 assert result == ["B", "C", "A"]16def test_topological_order_cycle():17 graph = OrderedDict()18 graph["A"] = "B", "C"19 graph["B"] = ("A",)20 with pytest.raises(ValueError, match="A | B"):21 stable_topological_sort(graph)22def test_topological_complex():23 graph = OrderedDict()24 graph["A"] = "B", "C"25 graph["B"] = "C", "D"26 graph["C"] = ("D",)27 graph["D"] = ()28 result = stable_topological_sort(graph)29 assert result == ["D", "C", "B", "A"]30def test_two_sub_graph():31 graph = OrderedDict()32 graph["F"] = ()33 graph["E"] = ()34 graph["D"] = "E", "F"35 graph["A"] = "B", "C"36 graph["B"] = ()37 graph["C"] = ()38 result = stable_topological_sort(graph)39 assert result == ["F", "E", "D", "B", "C", "A"]40def test_two_sub_graph_circle():41 graph = OrderedDict()42 graph["F"] = ()43 graph["E"] = ()44 graph["D"] = "E", "F"45 graph["A"] = "B", "C"46 graph["B"] = ("A",)47 graph["C"] = ()48 with pytest.raises(ValueError, match="A | B"):...`

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