diff --git a/.ruff.toml b/.ruff.toml
index 6832346226..c35507b5c3 100644
--- a/.ruff.toml
+++ b/.ruff.toml
@@ -34,7 +34,6 @@ lint.ignore = [
     "D100",  # Missing docstring in public module
     "D103",  # Missing docstring in public function
     "D200",  # One-line docstring should fit on one line
-    "D202",  # No blank lines allowed after function docstring
     "D205",  # 1 blank line required between summary line and description
     "D401",  # First line of docstring should be in imperative mood: ...
 
diff --git a/benchmarks/benchmarks/experimental/ugrid/regions_combine.py b/benchmarks/benchmarks/experimental/ugrid/regions_combine.py
index a4df9aa8c7..b47082590b 100644
--- a/benchmarks/benchmarks/experimental/ugrid/regions_combine.py
+++ b/benchmarks/benchmarks/experimental/ugrid/regions_combine.py
@@ -68,7 +68,6 @@ def _make_region_cubes(self, full_mesh_cube):
 
     def setup_cache(self):
         """Cache all the necessary source data on disk."""
-
         # Control dask, to minimise memory usage + allow largest data.
         self.fix_dask_settings()
 
@@ -106,7 +105,6 @@ def setup(self, n_cubesphere, imaginary_data=True, create_result_cube=True):
         NOTE: various test classes override + extend this.
 
         """
-
         # Load source cubes (full-mesh and regions)
         with PARSE_UGRID_ON_LOAD.context():
             self.full_mesh_cube = load_cube(
@@ -143,7 +141,6 @@ def fix_dask_settings(self):
         which is optimised for space saving so we can test largest data.
 
         """
-
         import dask.config as dcfg
 
         # Use single-threaded, to avoid process-switching costs and minimise memory usage.
diff --git a/benchmarks/benchmarks/generate_data/stock.py b/benchmarks/benchmarks/generate_data/stock.py
index 058eac01b1..a04eff6701 100644
--- a/benchmarks/benchmarks/generate_data/stock.py
+++ b/benchmarks/benchmarks/generate_data/stock.py
@@ -56,7 +56,6 @@ def create_file__xios_2d_face_half_levels(
     todo: is create_file__xios_2d_face_half_levels still appropriate now we can
      properly save Mesh Cubes?
     """
-
     return _create_file__xios_common(
         func_name="create_file__xios_2d_face_half_levels",
         dataset_name=dataset_name,
@@ -75,7 +74,6 @@ def create_file__xios_3d_face_half_levels(
     todo: is create_file__xios_3d_face_half_levels still appropriate now we can
      properly save Mesh Cubes?
     """
-
     return _create_file__xios_common(
         func_name="create_file__xios_3d_face_half_levels",
         dataset_name=dataset_name,
diff --git a/benchmarks/benchmarks/sperf/combine_regions.py b/benchmarks/benchmarks/sperf/combine_regions.py
index 1012ccd932..e591a120c9 100644
--- a/benchmarks/benchmarks/sperf/combine_regions.py
+++ b/benchmarks/benchmarks/sperf/combine_regions.py
@@ -64,7 +64,6 @@ def _make_region_cubes(self, full_mesh_cube):
 
     def setup_cache(self):
         """Cache all the necessary source data on disk."""
-
         # Control dask, to minimise memory usage + allow largest data.
         self.fix_dask_settings()
 
@@ -102,7 +101,6 @@ def setup(self, n_cubesphere, imaginary_data=True, create_result_cube=True):
         NOTE: various test classes override + extend this.
 
         """
-
         # Load source cubes (full-mesh and regions)
         with PARSE_UGRID_ON_LOAD.context():
             self.full_mesh_cube = load_cube(
@@ -142,7 +140,6 @@ def fix_dask_settings(self):
         which is optimised for space saving so we can test largest data.
 
         """
-
         import dask.config as dcfg
 
         # Use single-threaded, to avoid process-switching costs and minimise memory usage.
diff --git a/benchmarks/bm_runner.py b/benchmarks/bm_runner.py
index 0195d259fe..406c8eb3ae 100644
--- a/benchmarks/bm_runner.py
+++ b/benchmarks/bm_runner.py
@@ -68,7 +68,6 @@ def _check_requirements(package: str) -> None:
 
 def _prep_data_gen_env() -> None:
     """Create/access a separate, unchanging environment for generating test data."""
-
     python_version = "3.11"
     data_gen_var = "DATA_GEN_PYTHON"
     if data_gen_var in environ:
diff --git a/docs/gallery_code/general/plot_custom_file_loading.py b/docs/gallery_code/general/plot_custom_file_loading.py
index 53781ba044..81aad4a15a 100644
--- a/docs/gallery_code/general/plot_custom_file_loading.py
+++ b/docs/gallery_code/general/plot_custom_file_loading.py
@@ -89,11 +89,12 @@
 
 
 def load_NAME_III(filename):
-    """Loads the Met Office's NAME III grid output files returning headers, column
+    """Loads the Met Office's NAME III grid output files.
+
+    Loads the Met Office's NAME III grid output files returning headers, column
     definitions and data arrays as 3 separate lists.
 
     """
-
     # Loading a file gives a generator of lines which can be progressed using
     # the next() function. This will come in handy as we wish to progress
     # through the file line by line.
@@ -179,7 +180,6 @@ def load_NAME_III(filename):
 
 def NAME_to_cube(filenames, callback):
     """Returns a generator of cubes given a list of filenames and a callback."""
-
     for filename in filenames:
         header, column_headings, data_arrays = load_NAME_III(filename)
 
diff --git a/docs/gallery_code/meteorology/plot_COP_maps.py b/docs/gallery_code/meteorology/plot_COP_maps.py
index eda8a3a53a..5536823fb4 100644
--- a/docs/gallery_code/meteorology/plot_COP_maps.py
+++ b/docs/gallery_code/meteorology/plot_COP_maps.py
@@ -31,10 +31,7 @@
 
 
 def cop_metadata_callback(cube, field, filename):
-    """A function which adds an "Experiment" coordinate which comes from the
-    filename.
-    """
-
+    """Function which adds an "Experiment" coordinate which comes from the filename."""
     # Extract the experiment name (such as A1B or E1) from the filename (in
     # this case it is just the start of the file name, before the first ".").
     fname = os.path.basename(filename)  # filename without path.
diff --git a/docs/gallery_tests/test_gallery_examples.py b/docs/gallery_tests/test_gallery_examples.py
index 93f361a62a..83f2c93217 100644
--- a/docs/gallery_tests/test_gallery_examples.py
+++ b/docs/gallery_tests/test_gallery_examples.py
@@ -16,7 +16,6 @@
 
 def gallery_examples():
     """Generator to yield all current gallery examples."""
-
     for example_file in GALLERY_DIR.glob("*/plot*.py"):
         yield example_file.stem
 
@@ -30,7 +29,6 @@ def test_plot_example(
     iris_future_defaults,
 ):
     """Test that all figures from example code match KGO."""
-
     module = importlib.import_module(example)
 
     # Run example.
diff --git a/lib/iris/_concatenate.py b/lib/iris/_concatenate.py
index 97c2840958..b5c92fd6f9 100644
--- a/lib/iris/_concatenate.py
+++ b/lib/iris/_concatenate.py
@@ -759,7 +759,6 @@ def __init__(self, cube):
     @property
     def axis(self):
         """Return the nominated dimension of concatenation."""
-
         return self._axis
 
     def concatenate(self):
diff --git a/lib/iris/_lazy_data.py b/lib/iris/_lazy_data.py
index 81af368203..55a4222675 100644
--- a/lib/iris/_lazy_data.py
+++ b/lib/iris/_lazy_data.py
@@ -58,7 +58,9 @@ def _optimum_chunksize_internals(
     dims_fixed=None,
     dask_array_chunksize=dask.config.get("array.chunk-size"),
 ):
-    """Reduce or increase an initial chunk shape to get close to a chosen ideal
+    """Reduce or increase an initial chunk shap.
+
+    Reduce or increase an initial chunk shape to get close to a chosen ideal
     size, while prioritising the splitting of the earlier (outer) dimensions
     and keeping intact the later (inner) ones.
 
@@ -100,7 +102,6 @@ def _optimum_chunksize_internals(
     "chunks = [c[0] for c in normalise_chunks('auto', ...)]".
 
     """
-
     # Set the chunksize limit.
     if limit is None:
         # Fetch the default 'optimal' chunksize from the dask config.
diff --git a/lib/iris/_merge.py b/lib/iris/_merge.py
index 3bed7ef5ee..79427d401a 100644
--- a/lib/iris/_merge.py
+++ b/lib/iris/_merge.py
@@ -167,7 +167,6 @@ class _CoordPayload(namedtuple("CoordPayload", ["scalar", "vector", "factory_def
 
     def as_signature(self):
         """Construct and return a :class:`_CoordSignature` from the payload."""
-
         return _CoordSignature(
             self.scalar.defns,
             self.vector.dim_coords_and_dims,
@@ -1072,11 +1071,12 @@ class ProtoCube:
     """
 
     def __init__(self, cube):
-        """Create a new ProtoCube from the given cube and record the cube
-        as a source-cube.
+        """Create a new ProtoCube from the given cube.
 
-        """
+        Create a new ProtoCube from the given cube and record the cube as a
+        source-cube.
 
+        """
         # Default hint ordering for candidate dimension coordinates.
         self._hints = [
             "time",
@@ -1533,7 +1533,6 @@ def _nd_index(self, position):
         within the merged cube.
 
         """
-
         index = []
 
         # Determine the index of the source-cube cell for each dimension.
@@ -1634,7 +1633,6 @@ def _build_signature(self, cube):
         The cube signature.
 
         """
-
         return _CubeSignature(
             cube.metadata,
             cube.shape,
diff --git a/lib/iris/_representation/cube_printout.py b/lib/iris/_representation/cube_printout.py
index b1e5238eb0..fc8efb7cd6 100644
--- a/lib/iris/_representation/cube_printout.py
+++ b/lib/iris/_representation/cube_printout.py
@@ -268,7 +268,6 @@ def _decorated_table(table, name_padding=None):
         Note: 'name_padding' sets a minimum width for the name column (#0).
 
         """
-
         # Copy the input table + extract the header + its columns.
         table = table.copy()
         header = table.rows[0]
diff --git a/lib/iris/analysis/_regrid.py b/lib/iris/analysis/_regrid.py
index d4ccd6c203..0f50e47f5b 100644
--- a/lib/iris/analysis/_regrid.py
+++ b/lib/iris/analysis/_regrid.py
@@ -51,7 +51,6 @@ def _regrid_weighted_curvilinear_to_rectilinear__prepare(src_cube, weights, grid
     The 'regrid info' returned can be re-used over many cubes.
 
     """
-
     # Get the source cube x and y 2D auxiliary coordinates.
     sx, sy = src_cube.coord(axis="x"), src_cube.coord(axis="y")
     # Get the target grid cube x and y dimension coordinates.
diff --git a/lib/iris/analysis/cartography.py b/lib/iris/analysis/cartography.py
index 01c71b177a..68fad28d9c 100644
--- a/lib/iris/analysis/cartography.py
+++ b/lib/iris/analysis/cartography.py
@@ -1012,7 +1012,6 @@ def _transform_distance_vectors(u_dist, v_dist, ds, dx2, dy2):
         along the x and y directions of the target crs at each location.
 
     """
-
     # Scale input distance vectors --> source-coordinate differentials.
     u1, v1 = u_dist / ds.dx1, v_dist / ds.dy1
     # Transform vectors into the target system.
diff --git a/lib/iris/analysis/geometry.py b/lib/iris/analysis/geometry.py
index a07ef61a76..0e44990155 100644
--- a/lib/iris/analysis/geometry.py
+++ b/lib/iris/analysis/geometry.py
@@ -26,7 +26,6 @@ def _extract_relevant_cube_slice(cube, geometry):
     If cube and geometry don't overlap, returns None.
 
     """
-
     # Validate the input parameters
     if not cube.coords(axis="x") or not cube.coords(axis="y"):
         raise ValueError("The cube must contain x and y axes.")
@@ -177,7 +176,6 @@ def geometry_area_weights(cube, geometry, normalize=False):
         Default is False.
 
     """
-
     # extract smallest subcube containing geometry
     shape = cube.shape
     extraction_results = _extract_relevant_cube_slice(cube, geometry)
diff --git a/lib/iris/analysis/maths.py b/lib/iris/analysis/maths.py
index 0d865952ce..6cbdeb70ac 100644
--- a/lib/iris/analysis/maths.py
+++ b/lib/iris/analysis/maths.py
@@ -741,7 +741,6 @@ def apply_ufunc(ufunc, cube, other=None, new_unit=None, new_name=None, in_place=
         See more at :doc:`/userguide/real_and_lazy_data`.
 
     """
-
     if not isinstance(ufunc, np.ufunc):
         ufunc_name = getattr(ufunc, "__name__", "function passed to apply_ufunc")
         emsg = f"{ufunc_name} is not recognised, it is not an instance of numpy.ufunc"
@@ -1090,7 +1089,6 @@ def ws_units_func(u_cube, v_cube):
             cs_cube = cs_ifunc(cube, axis=1)
 
         """
-
         self._data_func_name = getattr(
             data_func, "__name__", "data_func argument passed to IFunc"
         )
diff --git a/lib/iris/analysis/stats.py b/lib/iris/analysis/stats.py
index 2f5b125e06..1fe958500b 100644
--- a/lib/iris/analysis/stats.py
+++ b/lib/iris/analysis/stats.py
@@ -71,7 +71,6 @@ def pearsonr(
     This operation is non-lazy.
 
     """
-
     # Assign larger cube to cube_1
     if cube_b.ndim > cube_a.ndim:
         cube_1 = cube_b
diff --git a/lib/iris/common/resolve.py b/lib/iris/common/resolve.py
index 992e6134c4..b35397ee58 100644
--- a/lib/iris/common/resolve.py
+++ b/lib/iris/common/resolve.py
@@ -1295,7 +1295,6 @@ def _metadata_resolve(self):
         'aux_coords' or 'dim_coords' of the participating cubes.
 
         """
-
         # Determine the cube dim, aux and scalar coordinate items
         # for each individual cube.
         self.lhs_cube_category = self._categorise_items(self.lhs_cube)
diff --git a/lib/iris/coord_systems.py b/lib/iris/coord_systems.py
index 33214ef5e0..d4d1aa66f7 100644
--- a/lib/iris/coord_systems.py
+++ b/lib/iris/coord_systems.py
@@ -1025,7 +1025,6 @@ def __init__(
         It is only valid to provide one of true_scale_lat and scale_factor_at_projection_origin
 
         """
-
         #: True latitude of planar origin in degrees.
         self.central_lat = float(central_lat)
 
@@ -1140,7 +1139,6 @@ def __init__(
 
 
         """
-
         super().__init__(
             central_lat=central_lat,
             central_lon=central_lon,
@@ -1200,7 +1198,6 @@ def __init__(
             secant_latitudes=(33, 45)
 
         """
-
         #: True latitude of planar origin in degrees.
         self.central_lat = _arg_default(central_lat, 39.0)
 
diff --git a/lib/iris/coords.py b/lib/iris/coords.py
index a1595530f9..14371ac3ee 100644
--- a/lib/iris/coords.py
+++ b/lib/iris/coords.py
@@ -1335,7 +1335,6 @@ def __common_cmp__(self, other, operator_method):
         Non-Cell vs Cell comparison is used to define Constraint matching.
 
         """
-
         if (isinstance(other, list) and len(other) == 1) or (
             isinstance(other, np.ndarray) and other.shape == (1,)
         ):
@@ -2019,7 +2018,6 @@ def contiguous_bounds(self):
 
     def is_monotonic(self):
         """Return True if, and only if, this Coord is monotonic."""
-
         if self.ndim != 1:
             raise iris.exceptions.CoordinateMultiDimError(self)
 
@@ -2120,7 +2118,6 @@ def collapsed(self, dims_to_collapse=None):
 
         Replaces the points & bounds with a simple bounded region.
         """
-
         # Ensure dims_to_collapse is a tuple to be able to pass
         # through to numpy
         if isinstance(dims_to_collapse, (int, np.integer)):
diff --git a/lib/iris/cube.py b/lib/iris/cube.py
index d60dd342b4..04cee11969 100644
--- a/lib/iris/cube.py
+++ b/lib/iris/cube.py
@@ -242,7 +242,6 @@ def insert(self, index, cube):
 
     def xml(self, checksum=False, order=True, byteorder=True):
         """Return a string of the XML that this list of cubes represents."""
-
         doc = Document()
         cubes_xml_element = doc.createElement("cubes")
         cubes_xml_element.setAttribute("xmlns", XML_NAMESPACE_URI)
@@ -1152,7 +1151,6 @@ def _sort_xml_attrs(cls, doc):
 
         def _walk_nodes(node):
             """Note: _walk_nodes is called recursively on child elements."""
-
             # we don't want to copy the children here, so take a shallow copy
             new_node = node.cloneNode(deep=False)
 
@@ -1665,7 +1663,6 @@ def add_ancillary_variable(self, ancillary_variable, data_dims=None):
             Raises a ValueError if an ancillary variable with identical metadata
             already exists on the cube.
         """
-
         if self.ancillary_variables(ancillary_variable):
             raise iris.exceptions.CannotAddError(
                 "Duplicate ancillary variables not permitted"
@@ -4548,7 +4545,6 @@ def rolling_window(self, coord, aggregator, window, **kwargs):
             possible windows of size 3 from the original cube.
 
         """  # noqa: D214, D406, D407, D410, D411
-
         # Update weights kwargs (if necessary) to handle different types of
         # weights
         weights_info = None
diff --git a/lib/iris/experimental/ugrid/mesh.py b/lib/iris/experimental/ugrid/mesh.py
index dfd0d74552..79e67593d2 100644
--- a/lib/iris/experimental/ugrid/mesh.py
+++ b/lib/iris/experimental/ugrid/mesh.py
@@ -1440,7 +1440,6 @@ def connectivity(
             :class:`Mesh` that matched the given criteria.
 
         """
-
         result = self._connectivity_manager.filter(
             item=item,
             standard_name=standard_name,
diff --git a/lib/iris/fileformats/_ff.py b/lib/iris/fileformats/_ff.py
index 336c4aa699..5e65c92996 100644
--- a/lib/iris/fileformats/_ff.py
+++ b/lib/iris/fileformats/_ff.py
@@ -316,7 +316,6 @@ def __init__(self, filename, word_depth=DEFAULT_FF_WORD_DEPTH):
         FFHeader object.
 
         """
-
         #: File name of the FieldsFile.
         self.ff_filename = filename
         self._word_depth = word_depth
@@ -411,7 +410,6 @@ def shape(self, name):
         Dimension tuple.
 
         """
-
         if name in _FF_HEADER_POINTERS:
             value = getattr(self, name)[1:]
         else:
@@ -465,7 +463,6 @@ def __init__(self, filename, read_data=False, word_depth=DEFAULT_FF_WORD_DEPTH):
             ...     print(field)
 
         """
-
         self._ff_header = FFHeader(filename, word_depth=word_depth)
         self._word_depth = word_depth
         self._filename = filename
@@ -823,7 +820,6 @@ def _parse_binary_stream(file_like, dtype=np.float64, count=-1):
         object and generate as many values as possible.
 
     """
-
     # There are a wide range of types supported, we just need to know the byte
     # size of the object, so we just make sure we've go an instance of a
     # np.dtype
diff --git a/lib/iris/fileformats/_nc_load_rules/actions.py b/lib/iris/fileformats/_nc_load_rules/actions.py
index 92d46c6693..1532340d00 100644
--- a/lib/iris/fileformats/_nc_load_rules/actions.py
+++ b/lib/iris/fileformats/_nc_load_rules/actions.py
@@ -544,7 +544,6 @@ def run_actions(engine):
     The specific cube being translated is "engine.cube".
 
     """
-
     # default (all cubes) action, always runs
     action_default(engine)  # This should run the default rules.
 
diff --git a/lib/iris/fileformats/_nc_load_rules/helpers.py b/lib/iris/fileformats/_nc_load_rules/helpers.py
index 31cc4aaa6c..6a135a211c 100644
--- a/lib/iris/fileformats/_nc_load_rules/helpers.py
+++ b/lib/iris/fileformats/_nc_load_rules/helpers.py
@@ -275,7 +275,6 @@ def _split_cell_methods(nc_cell_methods: str) -> List[re.Match]:
     Validation of anything other than being laid out in the expected format is
     left to the calling function.
     """
-
     # Find name candidates
     name_start_inds = []
     for m in _CM_PARSE_NAME.finditer(nc_cell_methods):
@@ -346,7 +345,6 @@ def parse_cell_methods(nc_cell_methods):
     results are not affected.
 
     """
-
     cell_methods = []
     if nc_cell_methods is not None:
         for m in _split_cell_methods(nc_cell_methods):
@@ -952,7 +950,6 @@ def get_attr_units(cf_var, attributes):
 ################################################################################
 def get_names(cf_coord_var, coord_name, attributes):
     """Determine the standard_name, long_name and var_name attributes."""
-
     standard_name = getattr(cf_coord_var, CF_ATTR_STD_NAME, None)
     long_name = getattr(cf_coord_var, CF_ATTR_LONG_NAME, None)
     cf_name = str(cf_coord_var.cf_name)
@@ -1058,7 +1055,6 @@ def build_dimension_coordinate(
     engine, cf_coord_var, coord_name=None, coord_system=None
 ):
     """Create a dimension coordinate (DimCoord) and add it to the cube."""
-
     cf_var = engine.cf_var
     cube = engine.cube
     attributes = {}
@@ -1190,7 +1186,6 @@ def build_auxiliary_coordinate(
     engine, cf_coord_var, coord_name=None, coord_system=None
 ):
     """Create an auxiliary coordinate (AuxCoord) and add it to the cube."""
-
     cf_var = engine.cf_var
     cube = engine.cube
     attributes = {}
@@ -1499,7 +1494,6 @@ def is_time_period(engine, cf_name):
 ################################################################################
 def is_grid_mapping(engine, cf_name, grid_mapping):
     """Determine whether the CF grid mapping variable is of the appropriate type."""
-
     is_valid = False
     cf_var = engine.cf_var.cf_group[cf_name]
     attr_mapping_name = getattr(cf_var, CF_ATTR_GRID_MAPPING_NAME, None)
@@ -1513,7 +1507,6 @@ def is_grid_mapping(engine, cf_name, grid_mapping):
 ################################################################################
 def _is_rotated(engine, cf_name, cf_attr_value):
     """Determine whether the CF coordinate variable is rotated."""
-
     is_valid = False
     cf_var = engine.cf_var.cf_group[cf_name]
     attr_std_name = getattr(cf_var, CF_ATTR_STD_NAME, None)
@@ -1547,7 +1540,6 @@ def has_supported_mercator_parameters(engine, cf_name):
     Determine whether the CF grid mapping variable has the supported
     values for the parameters of the Mercator projection.
     """
-
     is_valid = True
     cf_grid_var = engine.cf_var.cf_group[cf_name]
 
@@ -1572,7 +1564,6 @@ def has_supported_polar_stereographic_parameters(engine, cf_name):
     """Determine whether the CF grid mapping variable has the supported
     values for the parameters of the Polar Stereographic projection.
     """
-
     is_valid = True
     cf_grid_var = engine.cf_var.cf_group[cf_name]
 
diff --git a/lib/iris/fileformats/abf.py b/lib/iris/fileformats/abf.py
index 3f7a6b18e0..13b0d8aa8d 100644
--- a/lib/iris/fileformats/abf.py
+++ b/lib/iris/fileformats/abf.py
@@ -116,7 +116,6 @@ def _read(self):
 
     def to_cube(self):
         """Return a new :class:`~iris.cube.Cube` from this ABFField."""
-
         cube = iris.cube.Cube(self.data)
 
         # Name.
diff --git a/lib/iris/fileformats/cf.py b/lib/iris/fileformats/cf.py
index 905e64ebc1..ec0d66f8c2 100644
--- a/lib/iris/fileformats/cf.py
+++ b/lib/iris/fileformats/cf.py
@@ -695,7 +695,6 @@ def cf_label_data(self, cf_data_var):
         str labels
 
         """
-
         if not isinstance(cf_data_var, CFDataVariable):
             raise TypeError(
                 "cf_data_var argument should be of type CFDataVariable. Got %r."
@@ -763,7 +762,6 @@ def cf_label_dimensions(self, cf_data_var):
         Tuple of label data dimension names.
 
         """
-
         if not isinstance(cf_data_var, CFDataVariable):
             raise TypeError(
                 "cf_data_var argument should be of type CFDataVariable. Got %r."
@@ -1086,7 +1084,6 @@ def __repr__(self):
 
     def _translate(self):
         """Classify the netCDF variables into CF-netCDF variables."""
-
         netcdf_variable_names = list(self._dataset.variables.keys())
 
         # Identify all CF coordinate variables first. This must be done
diff --git a/lib/iris/fileformats/name_loaders.py b/lib/iris/fileformats/name_loaders.py
index 3f4b2d13c6..545b242994 100644
--- a/lib/iris/fileformats/name_loaders.py
+++ b/lib/iris/fileformats/name_loaders.py
@@ -130,7 +130,6 @@ def _build_lat_lon_for_NAME_field(
     """Return regular latitude and longitude coordinates extracted from
     the provided header dictionary.
     """
-
     if x_or_y == "X":
         start = header["X grid origin"]
         step = header["X grid resolution"]
@@ -234,7 +233,6 @@ def _parse_units(units):
     An instance of :class:`cf_units.Unit`.
 
     """
-
     unit_mapper = {
         "Risks/m3": "1",  # Used for Bluetongue
         "TCID50s/m3": "1",  # Used for Foot and Mouth
@@ -284,7 +282,6 @@ def _cf_height_from_name(z_coord, lower_bound=None, upper_bound=None):
         interpretation of the supplied field heading.
 
     """
-
     # NAMEII - integer/float support.
     # Match against height agl, asl and Pa.
     pattern = re.compile(
@@ -955,7 +952,6 @@ def load_NAMEIII_version2(filename):
     A generator :class:`iris.cube.Cube` instances.
 
     """
-
     # loading a file gives a generator of lines which can be progressed
     # using the next() method. This will come in handy as we wish to
     # progress through the file line by line.
diff --git a/lib/iris/fileformats/nimrod.py b/lib/iris/fileformats/nimrod.py
index 8cf109eed5..778c7b3251 100644
--- a/lib/iris/fileformats/nimrod.py
+++ b/lib/iris/fileformats/nimrod.py
@@ -204,7 +204,6 @@ def _read_header_subset(self, infile, names, dtype):
 
     def _read_header(self, infile):
         """Load the 512 byte header (surrounded by 4-byte length)."""
-
         leading_length = struct.unpack(">L", infile.read(4))[0]
         if leading_length != 512:
             raise TranslationError("Expected header leading_length of 512")
diff --git a/lib/iris/plot.py b/lib/iris/plot.py
index 23d11bbdd4..d8e9426035 100644
--- a/lib/iris/plot.py
+++ b/lib/iris/plot.py
@@ -234,7 +234,6 @@ def _broadcast_2d(u, v):
 
 def _string_coord_axis_tick_labels(string_axes, axes=None):
     """Apply tick labels for string coordinates."""
-
     ax = axes if axes else plt.gca()
     for axis, ticks in string_axes.items():
         # Define a tick formatter. This will assign a label to all ticks
@@ -860,7 +859,6 @@ def _replace_axes_with_cartopy_axes(cartopy_proj):
     instance of :class:`cartopy.mpl.geoaxes.GeoAxes` then no action is taken.
 
     """
-
     ax = plt.gca()
     if not isinstance(ax, cartopy.mpl.geoaxes.GeoAxes):
         fig = ax.get_figure()
@@ -1229,7 +1227,6 @@ def orography_at_bounds(cube, facecolor="#888888", coords=None, axes=None):
     This function does not maintain laziness when called; it realises data.
     See more at :doc:`/userguide/real_and_lazy_data`.
     """
-
     # XXX Needs contiguous orography corners to work.
     raise NotImplementedError(
         "This operation is temporarily not provided "
@@ -1268,7 +1265,6 @@ def orography_at_points(cube, facecolor="#888888", coords=None, axes=None):
     This function does not maintain laziness when called; it realises data.
     See more at :doc:`/userguide/real_and_lazy_data`.
     """
-
     style_args = {"facecolor": facecolor}
 
     def vert_plot(u_coord, orography, style_args):
@@ -1843,7 +1839,6 @@ def citation(text, figure=None, axes=None):
         provided.
 
     """
-
     if text is not None and len(text):
         if figure is None and not axes:
             figure = plt.gcf()
diff --git a/lib/iris/quickplot.py b/lib/iris/quickplot.py
index fcb0b0d5b7..1fa2edd630 100644
--- a/lib/iris/quickplot.py
+++ b/lib/iris/quickplot.py
@@ -50,7 +50,6 @@ def _title(cube_or_coord, with_units):
 
 def _label(cube, mode, result=None, ndims=2, coords=None, axes=None):
     """Puts labels on the current plot using the given cube."""
-
     if axes is None:
         axes = plt.gca()
 
diff --git a/lib/iris/tests/stock/netcdf.py b/lib/iris/tests/stock/netcdf.py
index c1dd5cb631..5721433103 100644
--- a/lib/iris/tests/stock/netcdf.py
+++ b/lib/iris/tests/stock/netcdf.py
@@ -89,7 +89,6 @@ def _add_standard_data(nc_path, unlimited_dim_size=0):
     dimension size, 'dimension coordinates' and a possible unlimited dimension.
 
     """
-
     ds = _thread_safe_nc.DatasetWrapper(nc_path, "r+")
 
     unlimited_dim_names = [
diff --git a/lib/iris/tests/unit/analysis/test_MAX_RUN.py b/lib/iris/tests/unit/analysis/test_MAX_RUN.py
index d7cc714609..9e314aad7e 100644
--- a/lib/iris/tests/unit/analysis/test_MAX_RUN.py
+++ b/lib/iris/tests/unit/analysis/test_MAX_RUN.py
@@ -26,7 +26,6 @@ def setUp(self):
 
         Uses 1 and 3 rather than 1 and 0 to check that lambda is being applied.
         """
-
         self.data_1ds = [
             (np.array([3, 1, 1, 3, 3, 3]), 2),  # One run
             (np.array([3, 1, 1, 3, 1, 3]), 2),  # Two runs
@@ -60,7 +59,6 @@ def setUp(self):
 
         Uses 1 and 3 rather than 1 and 0 to check that lambda is being applied.
         """
-
         self.data_1ds = [
             (
                 ma.masked_array(
diff --git a/lib/iris/tests/unit/coord_categorisation/test_coord_categorisation.py b/lib/iris/tests/unit/coord_categorisation/test_coord_categorisation.py
index 2fc3db9b05..7730831e52 100644
--- a/lib/iris/tests/unit/coord_categorisation/test_coord_categorisation.py
+++ b/lib/iris/tests/unit/coord_categorisation/test_coord_categorisation.py
@@ -162,7 +162,6 @@ def test_add_season_nonstandard(cube, time_coord):
 )
 def test_add_season_year(cube, time_coord, backwards, nonstandard):
     """Specific test to account for the extra use_year_at_season_start argument."""
-
     kwargs = dict(
         cube=cube,
         coord=time_coord,
diff --git a/lib/iris/tests/unit/experimental/ugrid/mesh/test_Mesh.py b/lib/iris/tests/unit/experimental/ugrid/mesh/test_Mesh.py
index bc0daf14bc..48f9910099 100644
--- a/lib/iris/tests/unit/experimental/ugrid/mesh/test_Mesh.py
+++ b/lib/iris/tests/unit/experimental/ugrid/mesh/test_Mesh.py
@@ -1181,7 +1181,6 @@ def test_face_dimension_set(self):
 
     def test_remove_connectivities(self):
         """Do what 1D test could not - test removal of optional connectivity."""
-
         # Add an optional connectivity.
         self.mesh.add_connectivities(self.FACE_FACE)
         # Attempt to remove a non-existent connectivity.
diff --git a/lib/iris/tests/unit/fileformats/netcdf/saver/test_Saver__ugrid.py b/lib/iris/tests/unit/fileformats/netcdf/saver/test_Saver__ugrid.py
index 290cf0cfaf..241ff5a5cc 100644
--- a/lib/iris/tests/unit/fileformats/netcdf/saver/test_Saver__ugrid.py
+++ b/lib/iris/tests/unit/fileformats/netcdf/saver/test_Saver__ugrid.py
@@ -654,7 +654,6 @@ def test_alternate_cube_dim_order(self):
 
     def test_mixed_aux_coords(self):
         """``coordinates`` attribute should include mesh location coords and 'normal' coords."""
-
         cube = make_cube()
         mesh_dim = cube.mesh_dim()
         mesh_len = cube.shape[mesh_dim]
diff --git a/lib/iris/tests/unit/plot/test_plot.py b/lib/iris/tests/unit/plot/test_plot.py
index c4f65fb1a6..6adf1c4cf5 100644
--- a/lib/iris/tests/unit/plot/test_plot.py
+++ b/lib/iris/tests/unit/plot/test_plot.py
@@ -103,7 +103,6 @@ def check_paths(self, expected_path, expected_path_crs, lines, axes):
         plotted on the given geoaxes.
 
         """
-
         self.assertEqual(
             1, len(lines), "Expected a single line, got {}".format(len(lines))
         )
diff --git a/lib/iris/util.py b/lib/iris/util.py
index 686238fa61..d030924a52 100644
--- a/lib/iris/util.py
+++ b/lib/iris/util.py
@@ -193,7 +193,6 @@ def describe_diff(cube_a, cube_b, output_file=None):
     :meth:`iris.cube.Cube.is_compatible()`
 
     """
-
     if output_file is None:
         output_file = sys.stdout
 
@@ -253,7 +252,6 @@ def guess_coord_axis(coord):
     property ``ignore_axis`` to ``False``.
 
     """
-
     axis = None
 
     if hasattr(coord, "ignore_axis") and coord.ignore_axis is True:
@@ -1030,7 +1028,6 @@ def clip_string(the_str, clip_length=70, rider="..."):
     This function does maintain laziness when called; it doesn't realise data.
     See more at :doc:`/userguide/real_and_lazy_data`.
     """
-
     if clip_length >= len(the_str) or clip_length <= 0:
         return the_str
     else:
@@ -1064,7 +1061,6 @@ def format_array(arr):
     See more at :doc:`/userguide/real_and_lazy_data`.
 
     """
-
     max_line_len = 50
 
     result = np.array2string(
@@ -1232,7 +1228,6 @@ def squeeze(cube):
     See more at :doc:`/userguide/real_and_lazy_data`.
 
     """
-
     slices = [0 if cube.shape[dim] == 1 else slice(None) for dim in range(cube.ndim)]
 
     squeezed = cube[tuple(slices)]