diff --git a/docs/assets/ttt/ttt-ppp0101.py b/docs/assets/ttt/ttt-ppp0101.py
index 8a78180e..b36acb24 100644
--- a/docs/assets/ttt/ttt-ppp0101.py
+++ b/docs/assets/ttt/ttt-ppp0101.py
@@ -41,7 +41,7 @@
             l3 = Line(l2 @ 1, (0, 8))
             mirror(about=Plane.YZ)
         make_face()
-    extrude(amount=115/2, both=True, mode=Mode.SUBTRACT)
+    extrude(amount=115 / 2, both=True, mode=Mode.SUBTRACT)
 
 show_object(p)
 print(f"\npart mass = {p.part.volume*densa:0.2f}")
diff --git a/docs/pack_demo.py b/docs/pack_demo.py
index a5231541..7fd62594 100644
--- a/docs/pack_demo.py
+++ b/docs/pack_demo.py
@@ -10,8 +10,6 @@
 
 """
 
-
-
 # [import]
 from build123d import *
 from ocp_vscode import *
@@ -24,8 +22,6 @@
 b4 = Box(24, 24, 24, align=(Align.MAX, Align.MAX, Align.CENTER), mode=Mode.SUBTRACT)
 
 
-
-
 # [Export SVG files]
 def write_svg(part, filename: str, view_port_origin=(-100, 100, 150)):
     """Save an image of the BuildPart object as SVG"""
@@ -39,12 +35,15 @@ def write_svg(part, filename: str, view_port_origin=(-100, 100, 150)):
     exporter.write(f"assets/{filename}.svg")
 
 
-
-
 write_svg(
     Compound(
-        [b1, b2, b3, b4,],
-        "pack_demo_initial_state"
+        [
+            b1,
+            b2,
+            b3,
+            b4,
+        ],
+        "pack_demo_initial_state",
     ),
     "pack_demo_initial_state.svg",
     (50, 0, 100),
@@ -52,11 +51,7 @@ def write_svg(part, filename: str, view_port_origin=(-100, 100, 150)):
 
 # [pack 2D]
 
-xy_pack = pack(
-    [b1, b2, b3, b4],
-    padding=5,
-    align_z=False
-)
+xy_pack = pack([b1, b2, b3, b4], padding=5, align_z=False)
 
 write_svg(Compound(xy_pack), "pack_demo_packed_xy.svg", (50, 0, 100))
 
@@ -64,15 +59,11 @@ def write_svg(part, filename: str, view_port_origin=(-100, 100, 150)):
 # [Pack and align_z]
 
 
-z_pack = pack(
-    [b1, b2, b3, b4],
-    padding=5,
-    align_z=True
-)
+z_pack = pack([b1, b2, b3, b4], padding=5, align_z=True)
 
 write_svg(Compound(z_pack), "pack_demo_packed_z.svg", (50, 0, 100))
 
 
 # [bounding box]
 print(Compound(xy_pack).bounding_box())
-print(Compound(z_pack).bounding_box())
\ No newline at end of file
+print(Compound(z_pack).bounding_box())
diff --git a/examples/boxes_on_faces.py b/examples/boxes_on_faces.py
index 5698f7a3..002cf57a 100644
--- a/examples/boxes_on_faces.py
+++ b/examples/boxes_on_faces.py
@@ -23,6 +23,7 @@
     limitations under the License.
 
 """
+
 # [Imports]
 import build123d as bd
 from ocp_vscode import *
@@ -38,4 +39,4 @@
 
 if "show_object" in locals():
     show_object(bp.part.wrapped, name="box on faces")
-# [End]
\ No newline at end of file
+# [End]
diff --git a/examples/boxes_on_faces_algebra.py b/examples/boxes_on_faces_algebra.py
index 7f440583..b6cd56bc 100644
--- a/examples/boxes_on_faces_algebra.py
+++ b/examples/boxes_on_faces_algebra.py
@@ -11,4 +11,4 @@
 
 if "show_object" in locals():
     show_object(b, name="box on faces")
-# [End]
\ No newline at end of file
+# [End]
diff --git a/examples/build123d_logo.py b/examples/build123d_logo.py
index f5f03733..57db7b84 100644
--- a/examples/build123d_logo.py
+++ b/examples/build123d_logo.py
@@ -17,6 +17,7 @@
 image_files:
     - "example_build123d_logo_01.png"
 """
+
 # [Imports]
 from build123d import *
 from build123d import Shape
@@ -118,4 +119,4 @@ def add_svg_shape(svg: ExportSVG, shape: Shape, color: tuple[float, float, float
 show_object(three_d, name="three_d")
 show_object(extension_lines, name="extension_lines")
 show_object(build, name="build")
-# [End]
\ No newline at end of file
+# [End]
diff --git a/examples/circuit_board.py b/examples/circuit_board.py
index c222e409..0619bc19 100644
--- a/examples/circuit_board.py
+++ b/examples/circuit_board.py
@@ -46,4 +46,4 @@
     extrude(amount=pcb_height)
 
 show_object(pcb.part.wrapped)
-# [End]
\ No newline at end of file
+# [End]
diff --git a/examples/circuit_board_algebra.py b/examples/circuit_board_algebra.py
index 7e0e015a..132fa27a 100644
--- a/examples/circuit_board_algebra.py
+++ b/examples/circuit_board_algebra.py
@@ -1,6 +1,7 @@
 """
 for details see `circuit_board.py`
 """
+
 # [Imports]
 from itertools import product
 from build123d import *
@@ -23,4 +24,4 @@
 pcb = extrude(pcb, pcb_height)
 
 show(pcb)
-# [End]
\ No newline at end of file
+# [End]
diff --git a/examples/dual_color_3mf.py b/examples/dual_color_3mf.py
index b2c35d47..1f02c330 100644
--- a/examples/dual_color_3mf.py
+++ b/examples/dual_color_3mf.py
@@ -27,6 +27,7 @@
     limitations under the License.
 
 """
+
 from build123d import *
 from ocp_vscode import *
 
diff --git a/examples/joints.py b/examples/joints.py
index f143af5e..0bfb669a 100644
--- a/examples/joints.py
+++ b/examples/joints.py
@@ -1,6 +1,7 @@
 """
 Experimental Joint development file
 """
+
 from build123d import *
 from ocp_vscode import *
 
diff --git a/examples/lego.py b/examples/lego.py
index cbd7cadd..1a3d8d99 100644
--- a/examples/lego.py
+++ b/examples/lego.py
@@ -26,6 +26,7 @@
     See the License for the specific language governing permissions and
     limitations under the License.
 """
+
 from build123d import *
 from ocp_vscode import *
 
diff --git a/examples/packed_boxes.py b/examples/packed_boxes.py
index f037d2ca..1e53a08a 100644
--- a/examples/packed_boxes.py
+++ b/examples/packed_boxes.py
@@ -7,20 +7,24 @@
 desc: Demo packing a bunch of boxes in 2D.
 
 """
+
 import functools
 import operator
 import random
 import build123d as bd
 
 random.seed(123456)
-test_boxes = [bd.Box(random.randint(1, 20), random.randint(1, 20), random.randint(1, 5))
-              for _ in range(50)]
+test_boxes = [
+    bd.Box(random.randint(1, 20), random.randint(1, 20), random.randint(1, 5))
+    for _ in range(50)
+]
 packed = bd.pack(test_boxes, 3)
 
+
 # Lifted from https://build123d.readthedocs.io/en/latest/import_export.html#d-to-2d-projection
 def export_svg(parts, name):
     part = functools.reduce(operator.add, parts, bd.Part())
-    view_port_origin=(0, 0, 150)
+    view_port_origin = (0, 0, 150)
     visible, hidden = part.project_to_viewport(view_port_origin)
     max_dimension = max(*bd.Compound(children=visible + hidden).bounding_box().size)
     exporter = bd.ExportSVG(scale=100 / max_dimension)
@@ -30,5 +34,6 @@ def export_svg(parts, name):
     exporter.add_shape(hidden, layer="Hidden")
     exporter.write(f"../docs/assets/{name}.svg")
 
+
 export_svg(test_boxes, "packed_boxes_input")
 export_svg(packed, "packed_boxes_output")
diff --git a/examples/python_logo.py b/examples/python_logo.py
index cacd020a..a926ccdb 100644
--- a/examples/python_logo.py
+++ b/examples/python_logo.py
@@ -25,6 +25,7 @@
     limitations under the License.
 
 """
+
 from build123d import *
 from ocp_vscode import show
 
diff --git a/examples/roller_coaster.py b/examples/roller_coaster.py
index 75be1d95..4e513d8d 100644
--- a/examples/roller_coaster.py
+++ b/examples/roller_coaster.py
@@ -25,6 +25,7 @@
     See the License for the specific language governing permissions and
     limitations under the License.
 """
+
 from build123d import *
 from ocp_vscode import show_object
 
diff --git a/src/build123d/objects_curve.py b/src/build123d/objects_curve.py
index 0bce7c78..90f92873 100644
--- a/src/build123d/objects_curve.py
+++ b/src/build123d/objects_curve.py
@@ -584,7 +584,9 @@ def __init__(
         else:
             jern_workplane = copy.copy(WorkplaneList._get_context().workplanes[0])
         jern_workplane.origin = start
-        start_tangent = Vector(tangent).transform(jern_workplane.reverse_transform, is_direction=True)
+        start_tangent = Vector(tangent).transform(
+            jern_workplane.reverse_transform, is_direction=True
+        )
 
         arc_direction = copysign(1.0, arc_size)
         self.center_point = start + start_tangent.rotate(
diff --git a/src/build123d/pack.py b/src/build123d/pack.py
index 88ca5804..63b01cfa 100644
--- a/src/build123d/pack.py
+++ b/src/build123d/pack.py
@@ -119,7 +119,9 @@ def grow_down(w, h):
     return [(t[1], t[2]) for t in sorted(translations, key=lambda t: t[0])]
 
 
-def pack(objects: Collection[Shape], padding: float, align_z: bool = False) -> Collection[Shape]:
+def pack(
+    objects: Collection[Shape], padding: float, align_z: bool = False
+) -> Collection[Shape]:
     """Pack objects in a squarish area in Plane.XY.
 
     Args:
@@ -138,7 +140,9 @@ def pack(objects: Collection[Shape], padding: float, align_z: bool = False) -> C
         length_fn=lambda o: bounding_boxes[cast(Shape, o)].Y,
     )
     translated = [
-        Location((t[0] - o.bounding_box().min.X, t[1] - o.bounding_box().min.Y, 0)) * Pos((0, 0, -o.bounding_box().min.Z if align_z else 0)) * o
+        Location((t[0] - o.bounding_box().min.X, t[1] - o.bounding_box().min.Y, 0))
+        * Pos((0, 0, -o.bounding_box().min.Z if align_z else 0))
+        * o
         for (o, t) in zip(objects, translations)
     ]
 
diff --git a/tests/test_build_common.py b/tests/test_build_common.py
index a4c6e0e7..55e44f1e 100644
--- a/tests/test_build_common.py
+++ b/tests/test_build_common.py
@@ -329,7 +329,7 @@ def test_hex_major_radius(self):
         self.assertAlmostEqual(hloc.radius, 1, 7)
         self.assertAlmostEqual(hloc.diagonal, 2, 7)
         self.assertAlmostEqual(hloc.apothem, 3**0.5 / 2, 7)
-    
+
     def test_centering(self):
         with BuildSketch():
             with GridLocations(4, 4, 2, 2, align=(Align.CENTER, Align.CENTER)) as l:
diff --git a/tests/test_build_line.py b/tests/test_build_line.py
index e851ce2c..d2576845 100644
--- a/tests/test_build_line.py
+++ b/tests/test_build_line.py
@@ -209,21 +209,23 @@ def test_jern_arc(self):
             j1 = JernArc((1, 0), (0, 1), 1, 90)
         self.assertTupleAlmostEquals((jern.line @ 1).to_tuple(), (0, 1, 0), 5)
         self.assertAlmostEqual(j1.radius, 1)
-        self.assertAlmostEqual(j1.length, pi/2)
+        self.assertAlmostEqual(j1.length, pi / 2)
 
         with BuildLine(Plane.XY.offset(1)) as offset_l:
             off1 = JernArc((1, 0), (0, 1), 1, 90)
         self.assertTupleAlmostEquals((offset_l.line @ 1).to_tuple(), (0, 1, 1), 5)
         self.assertAlmostEqual(off1.radius, 1)
-        self.assertAlmostEqual(off1.length, pi/2)
+        self.assertAlmostEqual(off1.length, pi / 2)
 
         plane_iso = Plane(origin=(0, 0, 0), x_dir=(1, 1, 0), z_dir=(1, -1, 1))
         with BuildLine(plane_iso) as iso_l:
             iso1 = JernArc((0, 0), (0, 1), 1, 180)
-        self.assertTupleAlmostEquals((iso_l.line @ 1).to_tuple(), (-sqrt(2), -sqrt(2), 0), 5)
+        self.assertTupleAlmostEquals(
+            (iso_l.line @ 1).to_tuple(), (-sqrt(2), -sqrt(2), 0), 5
+        )
         self.assertAlmostEqual(iso1.radius, 1)
         self.assertAlmostEqual(iso1.length, pi)
-        
+
         with BuildLine() as full_l:
             l1 = JernArc(start=(0, 0, 0), tangent=(1, 0, 0), radius=1, arc_size=360)
             l2 = JernArc(start=(0, 0, 0), tangent=(1, 0, 0), radius=1, arc_size=300)
diff --git a/tests/test_exporters.py b/tests/test_exporters.py
index 8422d049..69a30a17 100644
--- a/tests/test_exporters.py
+++ b/tests/test_exporters.py
@@ -168,5 +168,6 @@ def test_color(self):
         svg.add_shape(sketch)
         svg.write("test-colors.svg")
 
+
 if __name__ == "__main__":
     unittest.main()