diff --git a/lib/iris/_data_manager.py b/lib/iris/_data_manager.py
index c5b7df8e1c..d27d759161 100644
--- a/lib/iris/_data_manager.py
+++ b/lib/iris/_data_manager.py
@@ -161,9 +161,11 @@ def _deepcopy(self, memo, data=None):
         try:
             if iris.FUTURE.dataless_cube and data is None:
                 shape = self.shape
-            elif (iris.FUTURE.dataless_cube and type(data) is str and data == iris.MAINTAIN_DATA) or (
-                data is None
-            ):
+            elif (
+                iris.FUTURE.dataless_cube
+                and type(data) is str
+                and data == iris.MAINTAIN_DATA
+            ) or (data is None):
                 # Copy the managed data.
                 if self.has_lazy_data():
                     data = copy.deepcopy(self._lazy_array, memo)
diff --git a/lib/iris/tests/unit/cube/test_Cube.py b/lib/iris/tests/unit/cube/test_Cube.py
index 7dc3068866..cf832719a0 100644
--- a/lib/iris/tests/unit/cube/test_Cube.py
+++ b/lib/iris/tests/unit/cube/test_Cube.py
@@ -2090,7 +2090,7 @@ def test_copy_new_data(self):
         _shared_utils.assert_array_equal(new_cube.data, new_data)
 
     def test_copy_remove_data(self):
-        with iris.FUTURE.context(dataless_cube = True):
+        with iris.FUTURE.context(dataless_cube=True):
             cube = stock.simple_3d()
             new_cube = cube.copy()
             assert new_cube.metadata == cube.metadata