simplify test

Author: matthiasdiener

test/test_graph_tools.py

@@ -77,11 +77,9 @@ def test_compute_topological_order():
         compute_topological_order(cycle)
 
     cycle2 = {0: [2], 1: [2], 2: [3], 3: [1]}
-    with pytest.raises(CycleError) as exc:
+    with pytest.raises(CycleError, match=r"\[1, 2, 3\]"):
         compute_topological_order(cycle2)
 
-    assert str(exc.value) == "[1, 2, 3]"
-
 
 def test_transitive_closure():
     from pytools.graph import compute_transitive_closure