Qiskit · IvanIsCoding · Sep 21, 2025 · Sep 21, 2025 · Sep 21, 2025 · Sep 21, 2025
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
@@ -37,8 +37,8 @@ jobs:
         run: cargo fmt --all -- --check
       - name: Clippy
         run: cargo clippy --workspace --all-targets -- -D warnings
-      - name: Black Codestyle Format
-        run: black --check --diff rustworkx tests
+      - name: Ruff Codestyle Format
+        run: ruff format --check --diff rustworkx tests
       - name: Python Lint
         run: ruff check rustworkx setup.py tests
       - name: Check stray release notes

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -285,7 +285,7 @@ cargo clippy --workspace --all-targets -- -D warnings
 
 Python is used primarily for tests and some small pieces of packaging
 and namespace configuration code in the actual library.
-[black](https://github.com/psf/black) and [flake8](https://flake8.pycqa.org/en/latest/) are used to enforce consistent
+[ruff](https://github.com/astral-sh/ruff) is used to enforce consistent
 style in the python code in the repository. You can run them via Nox using:
 
 ```bash
@@ -295,7 +295,7 @@ nox -e lint
 This will also run `cargo fmt` in check mode to ensure that you ran `cargo fmt`
 and will fail if the Rust code doesn't conform to the style rules.
 
-If black returns a code formatting error you can run `nox -e black` to automatically
+If ruff returns a code formatting error you can run `nox -e format` to automatically
 update the code formatting to conform to the style.
 
 ### Building documentation

diff --git a/noxfile.py b/noxfile.py
@@ -31,7 +31,7 @@ def test_with_version(session):
 
 @nox.session(python=["3"])
 def lint(session):
-    black(session)
+    format(session)
     typos(session)
     session.install(*lint_deps)
     session.run("ruff", "check", "rustworkx", "setup.py")
@@ -71,10 +71,15 @@ def docs_clean(session):
     session.chdir("docs")
     session.run("rm", "-rf", "build", "source/apiref", external=True)
 
+@nox.session(python=["3"])
+def format(session):
+    session.install(*[d for d in lint_deps if "ruff" in d])
+    session.run("ruff", "format", "rustworkx", "tests", *session.posargs)
+
 @nox.session(python=["3"])
 def black(session):
-    session.install(*[d for d in lint_deps if "black" in d])
-    session.run("black", "rustworkx", "tests", *session.posargs)
+    # Legacy black formatting session is aliased
+    format(session)
 
 @nox.session(python=["3"])
 def typos(session):

diff --git a/pyproject.toml b/pyproject.toml
@@ -76,7 +76,6 @@ test = [
   "stestr>=4.1",
 ]
 lint = [
-    "black~=25.9",
     "ruff==0.14.3",
     "setuptools-rust",
     "typos~=1.39",
@@ -103,12 +102,8 @@ releaseinfra = [
     "cibuildwheel==3.3.0; python_version >= '3.11'",
 ]
 
-[tool.black]
-line-length = 100
-target-version = ['py310', 'py311', 'py312', 'py313', 'py314']
-
 [tool.ruff]
-line-length = 105 # more lenient than black due to long function signatures
+line-length = 100
 src = ["rustworkx", "setup.py", "tests"]
 lint.select = [
     "E",   # pycodestyle
@@ -124,6 +119,14 @@ extend-exclude = ["doc"]
 "rustworkx/__init__.py" = ["F405", "F403"]
 "*.pyi" = ["F403", "F405", "PYI001", "PYI002"]
 
+[tool.ruff.lint.pycodestyle]
+max-line-length = 105 #  lint has a larger limit than the formatter because of long signatures
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"
+docstring-code-format = true
+
 [tool.typos.default]
 extend-ignore-words-re = [
   "[Ss]toer",

diff --git a/rustworkx/__init__.py b/rustworkx/__init__.py
@@ -85,12 +85,14 @@ class PyDAG(PyDiGraph):
     attribute to True. For example::
 
         import rustworkx as rx
+
         dag = rx.PyDAG()
         dag.check_cycle = True
 
     or at object creation::
 
         import rustworkx as rx
+
         dag = rx.PyDAG(check_cycle=True)
 
     With check_cycle set to true any calls to :meth:`PyDAG.add_edge` will
@@ -110,6 +112,7 @@ class PyDAG(PyDiGraph):
     For example::
 
         import rustworkx as rx
+
         dag = rx.PyDAG(multigraph=False)
 
     This can only be set at ``PyDiGraph`` initialization and not adjusted after
@@ -303,7 +306,7 @@ def floyd_warshall(
         tells rustworkx/rust how to extract a numerical weight as a ``float``
         for edge object. Some simple examples are::
 
-            floyd_warshall(graph, weight_fn= lambda x: 1)
+            floyd_warshall(graph, weight_fn=lambda x: 1)
 
         to return a weight of 1 for all edges. Also::
 
@@ -489,7 +492,7 @@ def all_pairs_dijkstra_shortest_paths(graph, edge_cost_fn):
         of node indices making the path. For example::
 
             {
-                0: {1: [0, 1],  2: [0, 1, 2]},
+                0: {1: [0, 1], 2: [0, 1, 2]},
                 1: {2: [1, 2]},
                 2: {0: [2, 0]},
             }
@@ -669,8 +672,7 @@ def is_isomorphic(
 
             graph_a = rustworkx.PyGraph()
             graph_b = rustworkx.PyGraph()
-            rustworkx.is_isomorphic(graph_a, graph_b,
-                                lambda x, y: x == y)
+            rustworkx.is_isomorphic(graph_a, graph_b, lambda x, y: x == y)
 
     .. note::
 
@@ -717,8 +719,7 @@ def is_isomorphic_node_match(first, second, matcher, id_order=True):
 
         graph_a = rustworkx.PyDAG()
         graph_b = rustworkx.PyDAG()
-        rustworkx.is_isomorphic_node_match(graph_a, graph_b,
-                                        lambda x, y: x == y)
+        rustworkx.is_isomorphic_node_match(graph_a, graph_b, lambda x, y: x == y)
 
     .. note::
 
@@ -768,8 +769,7 @@ def is_subgraph_isomorphic(
 
             graph_a = rustworkx.PyGraph()
             graph_b = rustworkx.PyGraph()
-            rustworkx.is_subgraph_isomorphic(graph_a, graph_b,
-                                            lambda x, y: x == y)
+            rustworkx.is_subgraph_isomorphic(graph_a, graph_b, lambda x, y: x == y)
 
 
     :param first: The first graph to compare. Can either be a
@@ -2018,7 +2018,7 @@ def all_pairs_bellman_ford_shortest_paths(graph, edge_cost_fn):
         of node indices making the path. For example::
 
             {
-                0: {1: [0, 1],  2: [0, 1, 2]},
+                0: {1: [0, 1], 2: [0, 1, 2]},
                 1: {2: [1, 2]},
                 2: {0: [2, 0]},
             }

diff --git a/rustworkx/visualization/matplotlib.py b/rustworkx/visualization/matplotlib.py
@@ -142,23 +142,23 @@ def mpl_draw(graph, pos=None, ax=None, arrows=True, with_labels=False, **kwds):
     :param func labels: An optional callback function that will be passed a
         node payload and return a string label for the node. For example::
 
-            labels=str
+            labels = str
 
         could be used to just return a string cast of the node's data payload.
         Or something like::
 
-            labels=lambda node: node['label']
+            labels = lambda node: node["label"]
 
         could be used if the node payloads are dictionaries.
     :param func edge_labels: An optional callback function that will be passed
         an edge payload and return a string label for the edge. For example::
 
-            edge_labels=str
+            edge_labels = str
 
         could be used to just return a string cast of the edge's data payload.
         Or something like::
 
-            edge_labels=lambda edge: edge['label']
+            edge_labels = lambda edge: edge["label"]
 
         could be used if the edge payloads are dictionaries. If this is set
         edge labels will be drawn in the visualization.

diff --git a/tests/digraph/test_bfs_search.py b/tests/digraph/test_bfs_search.py
@@ -57,7 +57,6 @@ def tree_edge(self, edge):
 
     def test_digraph_bfs_tree_edges_restricted(self):
         class TreeEdgesRecorderRestricted(rustworkx.visit.BFSVisitor):
-
             prohibited = [(0, 2), (1, 2)]
 
             def __init__(self):
@@ -75,7 +74,6 @@ def tree_edge(self, edge):
 
     def test_digraph_bfs_goal_search_with_stop_search_exception(self):
         class GoalSearch(rustworkx.visit.BFSVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -107,7 +105,6 @@ class StopIfGoalFound(Exception):
             pass
 
         class GoalSearch(rustworkx.visit.BFSVisitor):
-
             goal = 3
 
             def __init__(self):

diff --git a/tests/digraph/test_dfs_search.py b/tests/digraph/test_dfs_search.py
@@ -57,7 +57,6 @@ def tree_edge(self, edge):
 
     def test_digraph_dfs_tree_edges_restricted(self):
         class TreeEdgesRecorderRestricted(rustworkx.visit.DFSVisitor):
-
             prohibited = [(0, 1), (5, 3)]
 
             def __init__(self):
@@ -75,7 +74,6 @@ def tree_edge(self, edge):
 
     def test_digraph_dfs_goal_search(self):
         class GoalSearch(rustworkx.visit.DFSVisitor):
-
             goal = 3
 
             def __init__(self):

diff --git a/tests/digraph/test_dijkstra_search.py b/tests/digraph/test_dijkstra_search.py
@@ -71,7 +71,6 @@ def edge_relaxed(self, edge):
 
     def test_digraph_dijkstra_goal_search_with_stop_search_exception(self):
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -107,7 +106,6 @@ class StopIfGoalFound(Exception):
             pass
 
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -143,7 +141,6 @@ def reconstruct_path(self):
 
     def test_digraph_dijkstra_goal_search_with_prohibited_edges(self):
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
             prohibited = [(5, 3)]
 

diff --git a/tests/graph/test_bfs_search.py b/tests/graph/test_bfs_search.py
@@ -57,7 +57,6 @@ def tree_edge(self, edge):
 
     def test_graph_bfs_tree_edges_restricted(self):
         class TreeEdgesRecorderRestricted(rustworkx.visit.BFSVisitor):
-
             prohibited = [(0, 2), (1, 2)]
 
             def __init__(self):
@@ -75,7 +74,6 @@ def tree_edge(self, edge):
 
     def test_graph_bfs_goal_search_with_stop_search_exception(self):
         class GoalSearch(rustworkx.visit.BFSVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -107,7 +105,6 @@ class StopIfGoalFound(Exception):
             pass
 
         class GoalSearch(rustworkx.visit.BFSVisitor):
-
             goal = 3
 
             def __init__(self):

diff --git a/tests/graph/test_dfs_search.py b/tests/graph/test_dfs_search.py
@@ -57,7 +57,6 @@ def tree_edge(self, edge):
 
     def test_graph_dfs_tree_edges_restricted(self):
         class TreeEdgesRecorderRestricted(rustworkx.visit.DFSVisitor):
-
             prohibited = [(0, 2), (1, 2)]
 
             def __init__(self):
@@ -75,7 +74,6 @@ def tree_edge(self, edge):
 
     def test_graph_dfs_goal_search(self):
         class GoalSearch(rustworkx.visit.DFSVisitor):
-
             goal = 3
 
             def __init__(self):

diff --git a/tests/graph/test_dijkstra_search.py b/tests/graph/test_dijkstra_search.py
@@ -71,7 +71,6 @@ def edge_relaxed(self, edge):
 
     def test_graph_dijkstra_goal_search_with_stop_search_exception(self):
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -107,7 +106,6 @@ class StopIfGoalFound(Exception):
             pass
 
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
 
             def __init__(self):
@@ -143,7 +141,6 @@ def reconstruct_path(self):
 
     def test_graph_dijkstra_goal_search_with_prohibited_edges(self):
         class GoalSearch(rustworkx.visit.DijkstraVisitor):
-
             goal = 3
             prohibited = [(5, 3)]
 

diff --git a/tests/graph/test_dot.py b/tests/graph/test_dot.py
@@ -112,15 +112,15 @@ def test_graph_empty_dicts(self):
         graph = rustworkx.undirected_gnp_random_graph(3, 0.9, seed=42)
         dot_str = graph.to_dot(lambda _: {}, lambda _: {})
         self.assertEqual(
-            "graph {\n0 ;\n1 ;\n2 ;\n1 -- 0 ;\n2 -- 0 ;\n" "2 -- 1 ;\n}\n",
+            "graph {\n0 ;\n1 ;\n2 ;\n1 -- 0 ;\n2 -- 0 ;\n2 -- 1 ;\n}\n",
             dot_str,
         )
 
     def test_graph_graph_attrs(self):
         graph = rustworkx.undirected_gnp_random_graph(3, 0.9, seed=42)
         dot_str = graph.to_dot(lambda _: {}, lambda _: {}, {"bgcolor": "red"})
         self.assertEqual(
-            "graph {\nbgcolor=red ;\n0 ;\n1 ;\n2 ;\n1 -- 0 ;\n" "2 -- 0 ;\n2 -- 1 ;\n}\n",
+            "graph {\nbgcolor=red ;\n0 ;\n1 ;\n2 ;\n1 -- 0 ;\n2 -- 0 ;\n2 -- 1 ;\n}\n",
             dot_str,
         )
 
@@ -150,7 +150,6 @@ def test_from_dot_digraph(self):
         self.assertEqual(len(g.edges()), 1)
 
     def test_graph_roundtrip_with_attrs(self):
-
         graph = rustworkx.PyGraph()
         graph.add_node(
             {

diff --git a/tests/graph/test_geometry.py b/tests/graph/test_geometry.py
@@ -18,7 +18,6 @@
 
 
 class TestHyperbolicGreedyRouting(unittest.TestCase):
-
     def test_invalid_node_error(self):
         graph = rx.PyGraph()
         positions = []

diff --git a/tests/graph/test_steiner_tree.py b/tests/graph/test_steiner_tree.py
@@ -64,7 +64,6 @@ def test_metric_closure(self):
             if edge in edges:
                 found = True
             if not found:
-
                 if (
                     edge[1],
                     edge[0],

diff --git a/tests/test_custom_return_types.py b/tests/test_custom_return_types.py
@@ -1202,10 +1202,8 @@ def test_str(self):
         # Since all_pairs_dijkstra_path_lengths() is parallel the order of the
         # output is non-deterministic
         valid_values = [
-            "AllPairsPathLengthMapping{1: PathLengthMapping{}, " "0: PathLengthMapping{1: 3.14}}",
-            "AllPairsPathLengthMapping{"
-            "0: PathLengthMapping{1: 3.14}, "
-            "1: PathLengthMapping{}}",
+            "AllPairsPathLengthMapping{1: PathLengthMapping{}, 0: PathLengthMapping{1: 3.14}}",
+            "AllPairsPathLengthMapping{0: PathLengthMapping{1: 3.14}, 1: PathLengthMapping{}}",
         ]
         self.assertIn(str(res), valid_values)
 

diff --git a/tests/test_dispatch.py b/tests/test_dispatch.py
@@ -17,7 +17,6 @@
 
 
 class TestDispatchPyGraph(unittest.TestCase):
-
     class_type = "PyGraph"
 
     def setUp(self):
@@ -103,5 +102,4 @@ def test_betweenness_centrality(self):
 
 
 class TestDispatchPyDiGraph(TestDispatchPyGraph):
-
     class_type = "PyDiGraph"