From e4d19ecb32998df5757bcc78b997f02e5d3514f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 08:22:31 +0200
Subject: [PATCH 01/11] Fix bare self.assertRaises

---
 holoviews/tests/plotting/matplotlib/test_graphplot.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/holoviews/tests/plotting/matplotlib/test_graphplot.py b/holoviews/tests/plotting/matplotlib/test_graphplot.py
index 327754fb11..b370b95ebb 100644
--- a/holoviews/tests/plotting/matplotlib/test_graphplot.py
+++ b/holoviews/tests/plotting/matplotlib/test_graphplot.py
@@ -206,7 +206,8 @@ def test_graph_op_node_alpha(self):
 
         if Version(mpl.__version__) < Version("3.4.0"):
             # Python 3.6 only support up to matplotlib 3.3
-            with self.assertRaises(Exception):
+            msg = 'TypeError: alpha must be a float or None'
+            with pytest.raises(AbbreviatedException, match=msg):
                 mpl_renderer.get_plot(graph)
         else:
             plot = mpl_renderer.get_plot(graph)

From 8069931f4b2f58e0a5c660754233e508f42b4f5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 08:50:34 +0200
Subject: [PATCH 02/11] B006 - Autofix mutable argument

---
 holoviews/annotators.py                     |  4 ++-
 holoviews/core/accessors.py                 | 16 ++++++---
 holoviews/core/boundingregion.py            |  4 ++-
 holoviews/core/data/__init__.py             | 16 ++++++---
 holoviews/core/data/array.py                |  8 +++--
 holoviews/core/data/cudf.py                 |  4 ++-
 holoviews/core/data/dask.py                 |  8 +++--
 holoviews/core/data/dictionary.py           |  8 +++--
 holoviews/core/data/grid.py                 | 12 +++++--
 holoviews/core/data/ibis.py                 |  8 +++--
 holoviews/core/data/image.py                |  4 ++-
 holoviews/core/data/multipath.py            |  8 +++--
 holoviews/core/data/pandas.py               |  8 +++--
 holoviews/core/data/spatialpandas.py        | 12 +++++--
 holoviews/core/data/xarray.py               |  8 +++--
 holoviews/core/element.py                   |  8 +++--
 holoviews/core/io.py                        | 40 ++++++++++++++++-----
 holoviews/core/ndmapping.py                 |  4 ++-
 holoviews/core/options.py                   | 16 ++++++---
 holoviews/core/pprint.py                    | 10 ++++--
 holoviews/core/spaces.py                    |  8 +++--
 holoviews/core/util.py                      | 20 ++++++++---
 holoviews/element/__init__.py               |  4 ++-
 holoviews/element/raster.py                 |  8 +++--
 holoviews/element/tabular.py                |  4 ++-
 holoviews/ipython/archive.py                |  4 ++-
 holoviews/operation/element.py              |  4 ++-
 holoviews/operation/normalization.py        |  8 +++--
 holoviews/plotting/bokeh/chart.py           |  4 ++-
 holoviews/plotting/bokeh/element.py         | 16 ++++++---
 holoviews/plotting/bokeh/plot.py            |  8 +++--
 holoviews/plotting/bokeh/selection.py       |  4 ++-
 holoviews/plotting/bokeh/util.py            |  4 ++-
 holoviews/plotting/mpl/plot.py              |  4 ++-
 holoviews/plotting/mpl/util.py              | 12 +++++--
 holoviews/plotting/plot.py                  |  6 +++-
 holoviews/plotting/renderer.py              |  6 +++-
 holoviews/plotting/util.py                  |  4 ++-
 holoviews/selection.py                      | 12 +++++--
 holoviews/streams.py                        | 32 +++++++++++++----
 holoviews/tests/core/test_dimensioned.py    |  6 +++-
 holoviews/tests/plotting/bokeh/test_plot.py |  4 ++-
 holoviews/util/__init__.py                  |  4 ++-
 holoviews/util/parser.py                    | 16 ++++++---
 holoviews/util/transform.py                 |  4 ++-
 45 files changed, 315 insertions(+), 97 deletions(-)

diff --git a/holoviews/annotators.py b/holoviews/annotators.py
index 9daf124816..15acd36f36 100644
--- a/holoviews/annotators.py
+++ b/holoviews/annotators.py
@@ -16,7 +16,7 @@
 from .streams import BoxEdit, PolyDraw, PolyEdit, Selection1D, PointDraw, CurveEdit
 
 
-def preprocess(function, current=[]):
+def preprocess(function, current=None):
     """
     Turns a param.depends watch call into a preprocessor method, i.e.
     skips all downstream events triggered by it.
@@ -25,6 +25,8 @@ def preprocess(function, current=[]):
           method which depends on a particular parameter.
           (see https://github.com/pyviz/param/issues/332)
     """
+    if current is None:
+        current = []
     def inner(*args, **kwargs):
         self = args[0]
         self.param._BATCH_WATCH = True
diff --git a/holoviews/core/accessors.py b/holoviews/core/accessors.py
index 63ff65d4c3..32c3a91e2a 100644
--- a/holoviews/core/accessors.py
+++ b/holoviews/core/accessors.py
@@ -92,7 +92,7 @@ class Apply(metaclass=AccessorPipelineMeta):
     def __init__(self, obj, mode=None):
         self._obj = obj
 
-    def __call__(self, apply_function, streams=[], link_inputs=True,
+    def __call__(self, apply_function, streams=None, link_inputs=True,
                  link_dataset=True, dynamic=None, per_element=False, **kwargs):
         """Applies a function to all (Nd)Overlay or Element objects.
 
@@ -132,6 +132,8 @@ def __call__(self, apply_function, streams=[], link_inputs=True,
             A new object where the function was applied to all
             contained (Nd)Overlay or Element objects.
         """
+        if streams is None:
+            streams = []
         from .data import Dataset
         from .dimension import ViewableElement
         from .element import Element
@@ -238,22 +240,26 @@ def opts(self, *args, **kwargs):
         kwargs['_method_args'] = args
         return self.__call__('opts', **kwargs)
 
-    def reduce(self, dimensions=[], function=None, spreadfn=None, **kwargs):
+    def reduce(self, dimensions=None, function=None, spreadfn=None, **kwargs):
         """Applies a reduce function to all ViewableElement objects.
 
         See :py:meth:`Dimensioned.opts` and :py:meth:`Apply.__call__`
         for more information.
         """
+        if dimensions is None:
+            dimensions = []
         kwargs['_method_args'] = (dimensions, function, spreadfn)
         kwargs['per_element'] = True
         return self.__call__('reduce', **kwargs)
 
-    def sample(self, samples=[], bounds=None, **kwargs):
+    def sample(self, samples=None, bounds=None, **kwargs):
         """Samples element values at supplied coordinates.
 
         See :py:meth:`Dataset.sample` and :py:meth:`Apply.__call__`
         for more information.
         """
+        if samples is None:
+            samples = []
         kwargs['_method_args'] = (samples, bounds)
         kwargs['per_element'] = True
         return self.__call__('sample', **kwargs)
@@ -357,7 +363,9 @@ def _transform_dimension(self, kdims, vdims, dimension):
             dimension = self._obj.vdims[idx]
         return dimension
 
-    def _create_expression_transform(self, kdims, vdims, exclude=[]):
+    def _create_expression_transform(self, kdims, vdims, exclude=None):
+        if exclude is None:
+            exclude = []
         from .dimension import dimension_name
         from ..util.transform import dim
 
diff --git a/holoviews/core/boundingregion.py b/holoviews/core/boundingregion.py
index 942a962c85..35f94c6c84 100644
--- a/holoviews/core/boundingregion.py
+++ b/holoviews/core/boundingregion.py
@@ -103,8 +103,10 @@ def __repr__(self):
         return self.__str__()
 
 
-    def script_repr(self, imports=[], prefix="    "):
+    def script_repr(self, imports=None, prefix="    "):
         # Generate import statement
+        if imports is None:
+            imports = []
         cls = self.__class__.__name__
         mod = self.__module__
         imports.append(f"from {mod} import {cls}")
diff --git a/holoviews/core/data/__init__.py b/holoviews/core/data/__init__.py
index 4ff02a87a6..ba82c8e7a0 100644
--- a/holoviews/core/data/__init__.py
+++ b/holoviews/core/data/__init__.py
@@ -431,7 +431,7 @@ def persist(self):
         self._cached = persisted
         return self
 
-    def closest(self, coords=[], **kwargs):
+    def closest(self, coords=None, **kwargs):
         """Snaps coordinate(s) to closest coordinate in Dataset
 
         Args:
@@ -444,6 +444,8 @@ def closest(self, coords=[], **kwargs):
         Raises:
             NotImplementedError: Raised if snapping is not supported
         """
+        if coords is None:
+            coords = []
         if self.ndims > 1:
             raise NotImplementedError("Closest method currently only "
                                       "implemented for 1D Elements")
@@ -717,7 +719,7 @@ def __getitem__(self, slices):
         return data
 
 
-    def sample(self, samples=[], bounds=None, closest=True, **kwargs):
+    def sample(self, samples=None, bounds=None, closest=True, **kwargs):
         """Samples values at supplied coordinates.
 
         Allows sampling of element with a list of coordinates matching
@@ -749,6 +751,8 @@ def sample(self, samples=[], bounds=None, closest=True, **kwargs):
         Returns:
             Element containing the sampled coordinates
         """
+        if samples is None:
+            samples = []
         if kwargs and samples != []:
             raise Exception('Supply explicit list of samples or kwargs, not both.')
         elif kwargs:
@@ -824,7 +828,7 @@ def sample(self, samples=[], bounds=None, closest=True, **kwargs):
         return self.clone(sampled, new_type=Table, datatype=datatype)
 
 
-    def reduce(self, dimensions=[], function=None, spreadfn=None, **reductions):
+    def reduce(self, dimensions=None, function=None, spreadfn=None, **reductions):
         """Applies reduction along the specified dimension(s).
 
         Allows reducing the values along one or more key dimension
@@ -852,6 +856,8 @@ def reduce(self, dimensions=[], function=None, spreadfn=None, **reductions):
         Returns:
             The Dataset after reductions have been applied.
         """
+        if dimensions is None:
+            dimensions = []
         if any(dim in self.vdims for dim in dimensions):
             raise Exception("Reduce cannot be applied to value dimensions")
         function, dims = self._reduce_map(dimensions, function, reductions)
@@ -941,7 +947,7 @@ def aggregate(self, dimensions=None, function=None, spreadfn=None, **kwargs):
                                   new_type=new_type, datatype=datatype)
 
 
-    def groupby(self, dimensions=[], container_type=HoloMap, group_type=None,
+    def groupby(self, dimensions=None, container_type=HoloMap, group_type=None,
                 dynamic=False, **kwargs):
         """Groups object by one or more dimensions
 
@@ -960,6 +966,8 @@ def groupby(self, dimensions=[], container_type=HoloMap, group_type=None,
             Returns object of supplied container_type containing the
             groups. If dynamic=True returns a DynamicMap instead.
         """
+        if dimensions is None:
+            dimensions = []
         if not isinstance(dimensions, list): dimensions = [dimensions]
         if not len(dimensions): dimensions = self.dimensions('key', True)
         if group_type is None: group_type = type(self)
diff --git a/holoviews/core/data/array.py b/holoviews/core/data/array.py
index d96e07d71f..c2ab3d97ea 100644
--- a/holoviews/core/data/array.py
+++ b/holoviews/core/data/array.py
@@ -106,7 +106,9 @@ def add_dimension(cls, dataset, dimension, dim_pos, values, vdim):
 
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         data = dataset.data
         if len(by) == 1:
             sorting = cls.values(dataset, by[0]).argsort()
@@ -210,7 +212,9 @@ def select(cls, dataset, selection_mask=None, **selection):
 
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         data = dataset.data
         mask = False
         for sample in samples:
diff --git a/holoviews/core/data/cudf.py b/holoviews/core/data/cudf.py
index 4a608a4fd6..42cb8b2c24 100644
--- a/holoviews/core/data/cudf.py
+++ b/holoviews/core/data/cudf.py
@@ -326,7 +326,9 @@ def iloc(cls, dataset, index):
 
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         cols = [dataset.get_dimension(d, strict=True).name for d in by]
         return dataset.data.sort_values(by=cols, ascending=not reverse)
 
diff --git a/holoviews/core/data/dask.py b/holoviews/core/data/dask.py
index 5952a84b10..3fcff7cb22 100644
--- a/holoviews/core/data/dask.py
+++ b/holoviews/core/data/dask.py
@@ -90,7 +90,9 @@ def range(cls, dataset, dimension):
             return dd.compute(column.min(), column.max())
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         dataset.param.warning('Dask dataframes do not support sorting')
         return dataset.data
 
@@ -249,7 +251,9 @@ def unpack_scalar(cls, dataset, data):
         return data.iat[0,0]
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         data = dataset.data
         dims = dataset.dimensions('key', label='name')
         mask = None
diff --git a/holoviews/core/data/dictionary.py b/holoviews/core/data/dictionary.py
index 53dcd1f838..07e8afa619 100644
--- a/holoviews/core/data/dictionary.py
+++ b/holoviews/core/data/dictionary.py
@@ -229,7 +229,9 @@ def mask(cls, dataset, mask, mask_value=np.nan):
 
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         by = [dataset.get_dimension(d).name for d in by]
         if len(by) == 1:
             sorting = cls.values(dataset, by[0]).argsort()
@@ -338,7 +340,9 @@ def select(cls, dataset, selection_mask=None, **selection):
 
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         mask = False
         for sample in samples:
             sample_mask = True
diff --git a/holoviews/core/data/grid.py b/holoviews/core/data/grid.py
index a92c779142..5501b6034b 100644
--- a/holoviews/core/data/grid.py
+++ b/holoviews/core/data/grid.py
@@ -298,7 +298,7 @@ def coords(cls, dataset, dim, ordered=False, expanded=False, edges=False):
 
 
     @classmethod
-    def canonicalize(cls, dataset, data, data_coords=None, virtual_coords=[]):
+    def canonicalize(cls, dataset, data, data_coords=None, virtual_coords=None):
         """
         Canonicalize takes an array of values as input and reorients
         and transposes it to match the canonical format expected by
@@ -313,6 +313,8 @@ def canonicalize(cls, dataset, data, data_coords=None, virtual_coords=[]):
         with a virtual integer index. This ensures these coordinates
         are not simply dropped.
         """
+        if virtual_coords is None:
+            virtual_coords = []
         if data_coords is None:
             data_coords = dataset.dimensions('key', label='name')[::-1]
 
@@ -641,10 +643,12 @@ def mask(cls, dataset, mask, mask_val=np.nan):
 
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
         """
         Samples the gridded data into dataset of samples.
         """
+        if samples is None:
+            samples = []
         ndims = dataset.ndims
         dimensions = dataset.dimensions(label='name')
         arrays = [dataset.data[vdim.name] for vdim in dataset.vdims]
@@ -742,7 +746,9 @@ def add_dimension(cls, dataset, dimension, dim_pos, values, vdim):
 
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         if not by or by in [dataset.kdims, dataset.dimensions()]:
             return dataset.data
         else:
diff --git a/holoviews/core/data/ibis.py b/holoviews/core/data/ibis.py
index 2041a57d2d..1b62701e09 100644
--- a/holoviews/core/data/ibis.py
+++ b/holoviews/core/data/ibis.py
@@ -189,7 +189,9 @@ def dtype(cls, dataset, dimension):
     dimension_type = dtype
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         if ibis4():
             return dataset.data.order_by([(dataset.get_dimension(x).name, not reverse) for x in by])
         else:
@@ -414,7 +416,9 @@ def select_mask(cls, dataset, selection):
         return predicates
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         import ibis
         dims = dataset.dimensions()
         data = dataset.data
diff --git a/holoviews/core/data/image.py b/holoviews/core/data/image.py
index 5e556af243..885aee9a54 100644
--- a/holoviews/core/data/image.py
+++ b/holoviews/core/data/image.py
@@ -239,7 +239,7 @@ def select(cls, dataset, selection_mask=None, **selection):
 
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
         """
         Sample the Raster along one or both of its dimensions,
         returning a reduced dimensionality type, which is either
@@ -248,6 +248,8 @@ def sample(cls, dataset, samples=[]):
         of the sampled unit indexed by the value in the new_xaxis
         tuple.
         """
+        if samples is None:
+            samples = []
         if len(samples[0]) == 1:
             select = {dataset.kdims[0].name: [s[0] for s in samples]}
             return tuple(dataset.select(**select).columns().values())
diff --git a/holoviews/core/data/multipath.py b/holoviews/core/data/multipath.py
index aea4bf4901..e328af2e50 100644
--- a/holoviews/core/data/multipath.py
+++ b/holoviews/core/data/multipath.py
@@ -300,7 +300,9 @@ def groupby(cls, dataset, dimensions, container_type, group_type, **kwargs):
             return container_type(grouped_data)
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         raise NotImplementedError('Sampling operation on subpaths not supported')
 
     @classmethod
@@ -348,7 +350,9 @@ def dtype(cls, dataset, dimension):
         return ds.interface.dtype(ds, dimension)
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         by = [dataset.get_dimension(d).name for d in by]
         if len(by) == 1:
             sorting = cls.values(dataset, by[0], False).argsort()
diff --git a/holoviews/core/data/pandas.py b/holoviews/core/data/pandas.py
index da5cf4403d..8b2fb7300e 100644
--- a/holoviews/core/data/pandas.py
+++ b/holoviews/core/data/pandas.py
@@ -319,7 +319,9 @@ def redim(cls, dataset, dimensions):
 
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         cols = [dataset.get_dimension(d, strict=True).name for d in by]
 
         if (not isinstance(dataset.data, pd.DataFrame) or
@@ -367,7 +369,9 @@ def values(
 
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         data = dataset.data
         mask = None
         for sample in samples:
diff --git a/holoviews/core/data/spatialpandas.py b/holoviews/core/data/spatialpandas.py
index 81d3df03b4..88bc202565 100644
--- a/holoviews/core/data/spatialpandas.py
+++ b/holoviews/core/data/spatialpandas.py
@@ -238,7 +238,9 @@ def aggregate(cls, columns, dimensions, function, **kwargs):
         raise NotImplementedError
 
     @classmethod
-    def sample(cls, columns, samples=[]):
+    def sample(cls, columns, samples=None):
+        if samples is None:
+            samples = []
         raise NotImplementedError
 
     @classmethod
@@ -250,7 +252,9 @@ def shape(cls, dataset):
         return (cls.length(dataset), len(dataset.dimensions()))
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         geo_dims = cls.geom_dims(dataset)
         if any(d in geo_dims for d in by):
             raise DataError("SpatialPandasInterface does not allow sorting "
@@ -670,7 +674,7 @@ def geom_to_holes(geom):
         return [[]]
 
 
-def to_spatialpandas(data, xdim, ydim, columns=[], geom='point'):
+def to_spatialpandas(data, xdim, ydim, columns=None, geom='point'):
     """Converts list of dictionary format geometries to spatialpandas line geometries.
 
     Args:
@@ -683,6 +687,8 @@ def to_spatialpandas(data, xdim, ydim, columns=[], geom='point'):
     Returns:
         A spatialpandas.GeoDataFrame version of the data
     """
+    if columns is None:
+        columns = []
     from spatialpandas import GeoSeries, GeoDataFrame
     from spatialpandas.geometry import (
         Point, Line, Polygon, Ring, LineArray, PolygonArray, PointArray,
diff --git a/holoviews/core/data/xarray.py b/holoviews/core/data/xarray.py
index 8b124e5384..cb9a1ac196 100644
--- a/holoviews/core/data/xarray.py
+++ b/holoviews/core/data/xarray.py
@@ -533,7 +533,9 @@ def reindex(cls, dataset, kdims=None, vdims=None):
         return dataset.data
 
     @classmethod
-    def sort(cls, dataset, by=[], reverse=False):
+    def sort(cls, dataset, by=None, reverse=False):
+        if by is None:
+            by = []
         return dataset
 
     @classmethod
@@ -643,7 +645,9 @@ def dframe(cls, dataset, dimensions):
         return data
 
     @classmethod
-    def sample(cls, dataset, samples=[]):
+    def sample(cls, dataset, samples=None):
+        if samples is None:
+            samples = []
         names = [kd.name for kd in dataset.kdims]
         samples = [dataset.data.sel(**{k: [v] for k, v in zip(names, s)}).to_dataframe().reset_index()
                    for s in samples]
diff --git a/holoviews/core/element.py b/holoviews/core/element.py
index 537d09c7e9..f0ab22e7c8 100644
--- a/holoviews/core/element.py
+++ b/holoviews/core/element.py
@@ -109,7 +109,7 @@ def closest(self, coords, **kwargs):
         """
         raise NotImplementedError
 
-    def sample(self, samples=[], bounds=None, closest=False, **sample_values):
+    def sample(self, samples=None, bounds=None, closest=False, **sample_values):
         """Samples values at supplied coordinates.
 
         Allows sampling of element with a list of coordinates matching
@@ -141,10 +141,12 @@ def sample(self, samples=[], bounds=None, closest=False, **sample_values):
         Returns:
             Element containing the sampled coordinates
         """
+        if samples is None:
+            samples = []
         raise NotImplementedError
 
 
-    def reduce(self, dimensions=[], function=None, spreadfn=None, **reduction):
+    def reduce(self, dimensions=None, function=None, spreadfn=None, **reduction):
         """Applies reduction along the specified dimension(s).
 
         Allows reducing the values along one or more key dimension
@@ -172,6 +174,8 @@ def reduce(self, dimensions=[], function=None, spreadfn=None, **reduction):
         Returns:
             The element after reductions have been applied.
         """
+        if dimensions is None:
+            dimensions = []
         raise NotImplementedError
 
 
diff --git a/holoviews/core/io.py b/holoviews/core/io.py
index c6a4af5b39..e1298d1c89 100644
--- a/holoviews/core/io.py
+++ b/holoviews/core/io.py
@@ -37,10 +37,12 @@
 from .util import unique_iterator, group_sanitizer, label_sanitizer
 
 
-def sanitizer(name, replacements=[(':','_'), ('/','_'), ('\\','_')]):
+def sanitizer(name, replacements=None):
     """
     String sanitizer to avoid problematic characters in filenames.
     """
+    if replacements is None:
+        replacements = [(':', '_'), ('/', '_'), ('\\', '_')]
     for old,new in replacements:
         name = name.replace(old,new)
     return name
@@ -160,7 +162,7 @@ def __call__(self, obj, fmt=None):
 
 
     @bothmethod
-    def save(self_or_cls, obj, basename, fmt=None, key={}, info={}, **kwargs):
+    def save(self_or_cls, obj, basename, fmt=None, key=None, info=None, **kwargs):
         """
         Similar to the call method except saves exporter data to disk
         into a file with specified basename. For exporters that
@@ -171,6 +173,10 @@ def save(self_or_cls, obj, basename, fmt=None, key={}, info={}, **kwargs):
         to update the output of the relevant key and info functions
         which is then saved (if supported).
         """
+        if info is None:
+            info = {}
+        if key is None:
+            key = {}
         raise NotImplementedError("Exporter save method not implemented.")
 
 
@@ -250,7 +256,11 @@ def __call__(self, obj, **kwargs):
         return data, {'file-ext': self.file_ext, 'mime_type':self.mime_type}
 
     @bothmethod
-    def save(self_or_cls, obj, filename, info={}, key={}, **kwargs):
+    def save(self_or_cls, obj, filename, info=None, key=None, **kwargs):
+        if key is None:
+            key = {}
+        if info is None:
+            info = {}
         data, base_info = self_or_cls(obj, **kwargs)
         key = self_or_cls._merge_metadata(obj, self_or_cls.key_fn, key)
         info = self_or_cls._merge_metadata(obj, self_or_cls.info_fn, info, base_info)
@@ -331,14 +341,22 @@ class Pickler(Exporter):
     file_ext = 'hvz'
 
 
-    def __call__(self, obj, key={}, info={}, **kwargs):
+    def __call__(self, obj, key=None, info=None, **kwargs):
+        if info is None:
+            info = {}
+        if key is None:
+            key = {}
         buff = BytesIO()
         self.save(obj, buff, key=key, info=info, **kwargs)
         buff.seek(0)
         return buff.read(), {'file-ext': 'hvz', 'mime_type':self.mime_type}
 
     @bothmethod
-    def save(self_or_cls, obj, filename, key={}, info={}, **kwargs):
+    def save(self_or_cls, obj, filename, key=None, info=None, **kwargs):
+        if info is None:
+            info = {}
+        if key is None:
+            key = {}
         base_info = {'file-ext': 'hvz', 'mime_type':self_or_cls.mime_type}
         key = self_or_cls._merge_metadata(obj, self_or_cls.key_fn, key)
         info = self_or_cls._merge_metadata(obj, self_or_cls.info_fn, info, base_info)
@@ -421,7 +439,7 @@ def entries(self_or_cls, filename):
             return [el for el in f.namelist() if el != 'metadata']
 
     @bothmethod
-    def collect(self_or_cls, files, drop=[], metadata=True):
+    def collect(self_or_cls, files, drop=None, metadata=True):
         """
         Given a list or NdMapping type containing file paths return a
         Layout of Collators, which can be called to load a given set
@@ -433,6 +451,8 @@ def collect(self_or_cls, files, drop=[], metadata=True):
         they do not clash with the file metadata. Any key dimension
         may be dropped by name by supplying a drop argument.
         """
+        if drop is None:
+            drop = []
         aslist = not isinstance(files, (NdMapping, Element))
         if isinstance(files, Element):
             files = Collator(files)
@@ -658,7 +678,7 @@ def _validate_formatters(self):
             raise Exception("Timestamp format invalid")
 
 
-    def add(self, obj=None, filename=None, data=None, info={}, **kwargs):
+    def add(self, obj=None, filename=None, data=None, info=None, **kwargs):
         """
         If a filename is supplied, it will be used. Otherwise, a
         filename will be generated from the supplied object. Note that
@@ -668,6 +688,8 @@ def add(self, obj=None, filename=None, data=None, info={}, **kwargs):
         The data to be archived is either supplied explicitly as
         'data' or automatically rendered from the object.
         """
+        if info is None:
+            info = {}
         if [filename, obj] == [None, None]:
             raise Exception("Either filename or a HoloViews object is "
                             "needed to create an entry in the archive.")
@@ -810,10 +832,12 @@ def _normalize_name(self, basename):
         return basename.replace(' ', '_')
 
 
-    def export(self, timestamp=None, info={}):
+    def export(self, timestamp=None, info=None):
         """
         Export the archive, directory or file.
         """
+        if info is None:
+            info = {}
         tval = tuple(time.localtime()) if timestamp is None else timestamp
         tstamp = time.strftime(self.timestamp_format, tval)
 
diff --git a/holoviews/core/ndmapping.py b/holoviews/core/ndmapping.py
index 4cc8c2392d..90ffcc6090 100644
--- a/holoviews/core/ndmapping.py
+++ b/holoviews/core/ndmapping.py
@@ -406,7 +406,7 @@ def dimension_values(self, dimension, expanded=True, flat=True):
             return super().dimension_values(dimension, expanded, flat)
 
 
-    def reindex(self, kdims=[], force=False):
+    def reindex(self, kdims=None, force=False):
         """Reindexes object dropping static or supplied kdims
 
         Creates a new object with a reordered or reduced set of key
@@ -424,6 +424,8 @@ def reindex(self, kdims=[], force=False):
         Returns:
             Reindexed object
         """
+        if kdims is None:
+            kdims = []
         old_kdims = [d.name for d in self.kdims]
         if not isinstance(kdims, list):
             kdims = [kdims]
diff --git a/holoviews/core/options.py b/holoviews/core/options.py
index cf341e2936..97b26901d8 100644
--- a/holoviews/core/options.py
+++ b/holoviews/core/options.py
@@ -258,8 +258,10 @@ class Keywords(param.Parameterized):
     target = param.String(allow_None=True, doc="""
        Optional string description of what the keywords apply to.""")
 
-    def __init__(self, values=[], target=None):
+    def __init__(self, values=None, target=None):
 
+        if values is None:
+            values = []
         strings = [isinstance(v, str) for v in values]
         if False in strings:
             raise ValueError(f'All keywords must be strings: {values}')
@@ -459,9 +461,11 @@ class Options:
 
     _output_allowed_kws = ['backend']
 
-    def __init__(self, key=None, allowed_keywords=[], merge_keywords=True,
+    def __init__(self, key=None, allowed_keywords=None, merge_keywords=True,
                  max_cycles=None, **kwargs):
 
+        if allowed_keywords is None:
+            allowed_keywords = []
         invalid_kws = []
         for kwarg in sorted(kwargs.keys()):
             if allowed_keywords and kwarg not in allowed_keywords:
@@ -1240,12 +1244,14 @@ def dumps(cls, obj, protocol=0):
 
     @classmethod
     def info(cls, obj, ansi=True, backend='matplotlib', visualization=True,
-             recursive=False, pattern=None, elements=[]):
+             recursive=False, pattern=None, elements=None):
         """
         Show information about a particular object or component class
         including the applicable style and plot options. Returns None if
         the object is not parameterized.
         """
+        if elements is None:
+            elements = []
         parameterized_object = isinstance(obj, param.Parameterized)
         parameterized_class = (isinstance(obj,type)
                                and  issubclass(obj,param.Parameterized))
@@ -1352,11 +1358,13 @@ def add_style_opts(cls, component, new_options, backend=None):
         )
 
     @classmethod
-    def register(cls, associations, backend, style_aliases={}):
+    def register(cls, associations, backend, style_aliases=None):
         """
         Register the supplied dictionary of associations between
         elements and plotting classes to the specified backend.
         """
+        if style_aliases is None:
+            style_aliases = {}
         if backend not in cls.registry:
             cls.registry[backend] = {}
         cls.registry[backend].update(associations)
diff --git a/holoviews/core/pprint.py b/holoviews/core/pprint.py
index 7ca8dd600b..279bec2967 100644
--- a/holoviews/core/pprint.py
+++ b/holoviews/core/pprint.py
@@ -132,11 +132,13 @@ def highlight(cls, pattern, string):
 
     @classmethod
     def info(cls, obj, ansi=False, backend='matplotlib', visualization=True,
-             pattern=None, elements=[]):
+             pattern=None, elements=None):
         """
         Show information about an object in the given category. ANSI
         color codes may be enabled or disabled.
         """
+        if elements is None:
+            elements = []
         cls.elements = elements
         ansi_escape = re.compile(r'\x1b[^m]*m')
 
@@ -296,11 +298,15 @@ def component_type(cls_or_slf, node):
         return cls_or_slf.type_formatter.format(type=str(type(node).__name__))
 
     @bothmethod
-    def recurse(cls_or_slf, node, attrpath=None, attrpaths=[], siblings=[], level=0, value_dims=True):
+    def recurse(cls_or_slf, node, attrpath=None, attrpaths=None, siblings=None, level=0, value_dims=True):
         """
         Recursive function that builds up an ASCII tree given an
         AttrTree node.
         """
+        if siblings is None:
+            siblings = []
+        if attrpaths is None:
+            attrpaths = []
         level, lines = cls_or_slf.node_info(node, attrpath, attrpaths, siblings, level, value_dims)
         attrpaths = ['.'.join(k) for k in node.keys()] if  hasattr(node, 'children') else []
         siblings = [node.get(child) for child in attrpaths]
diff --git a/holoviews/core/spaces.py b/holoviews/core/spaces.py
index 22298db4b8..13d0419752 100644
--- a/holoviews/core/spaces.py
+++ b/holoviews/core/spaces.py
@@ -304,7 +304,7 @@ def __lshift__(self, other):
             raise TypeError(f'Cannot append {type(other).__name__} to a AdjointLayout')
 
 
-    def collate(self, merge_type=None, drop=[], drop_constant=False):
+    def collate(self, merge_type=None, drop=None, drop_constant=False):
         """Collate allows reordering nested containers
 
         Collation allows collapsing nested mapping types by merging
@@ -328,6 +328,8 @@ def collate(self, merge_type=None, drop=[], drop_constant=False):
         Returns:
             Collated Layout or HoloMap
         """
+        if drop is None:
+            drop = []
         from .element import Collator
         merge_type=merge_type if merge_type else self.__class__
         return Collator(self, merge_type=merge_type, drop=drop,
@@ -1681,7 +1683,7 @@ def dynamic_hist(obj, **dynkwargs):
             return hist
 
 
-    def reindex(self, kdims=[], force=False):
+    def reindex(self, kdims=None, force=False):
         """Reorders key dimensions on DynamicMap
 
         Create a new object with a reordered set of key dimensions.
@@ -1694,6 +1696,8 @@ def reindex(self, kdims=[], force=False):
         Returns:
             Reindexed DynamicMap
         """
+        if kdims is None:
+            kdims = []
         if not isinstance(kdims, list):
             kdims = [kdims]
         kdims = [self.get_dimension(kd, strict=True) for kd in kdims]
diff --git a/holoviews/core/util.py b/holoviews/core/util.py
index 8fbfc1bea9..e5881a22a5 100644
--- a/holoviews/core/util.py
+++ b/holoviews/core/util.py
@@ -695,12 +695,18 @@ def remove_diacritics(self_or_cls, identifier):
         return chars
 
     @param.parameterized.bothmethod
-    def shortened_character_name(self_or_cls, c, eliminations=[], substitutions={}, transforms=[]):
+    def shortened_character_name(self_or_cls, c, eliminations=None, substitutions=None, transforms=None):
         """
         Given a unicode character c, return the shortened unicode name
         (as a list of tokens) by applying the eliminations,
         substitutions and transforms.
         """
+        if transforms is None:
+            transforms = []
+        if substitutions is None:
+            substitutions = {}
+        if eliminations is None:
+            eliminations = []
         name = unicodedata.name(c).lower()
         # Filtering
         for elim in eliminations:
@@ -922,12 +928,14 @@ def find_minmax(lims, olims):
     return limits
 
 
-def find_range(values, soft_range=[]):
+def find_range(values, soft_range=None):
     """
     Safely finds either the numerical min and max of
     a set of values, falling back to the first and
     the last value in the sorted list of values.
     """
+    if soft_range is None:
+        soft_range = []
     try:
         values = np.array(values)
         values = np.squeeze(values) if len(values.shape) > 1 else values
@@ -1658,7 +1666,7 @@ def wrap_tuple(unwrapped):
     return (unwrapped if isinstance(unwrapped, tuple) else (unwrapped,))
 
 
-def stream_name_mapping(stream, exclude_params=['name'], reverse=False):
+def stream_name_mapping(stream, exclude_params=None, reverse=False):
     """
     Return a complete dictionary mapping between stream parameter names
     to their applicable renames, excluding parameters listed in
@@ -1667,6 +1675,8 @@ def stream_name_mapping(stream, exclude_params=['name'], reverse=False):
     If reverse is True, the mapping is from the renamed strings to the
     original stream parameter names.
     """
+    if exclude_params is None:
+        exclude_params = ['name']
     from ..streams import Params
     if isinstance(stream, Params):
         mapping = {}
@@ -1703,7 +1713,7 @@ def rename_stream_kwargs(stream, kwargs, reverse=False):
     return mapped_kwargs
 
 
-def stream_parameters(streams, no_duplicates=True, exclude=['name', '_memoize_key']):
+def stream_parameters(streams, no_duplicates=True, exclude=None):
     """
     Given a list of streams, return a flat list of parameter name,
     excluding those listed in the exclude list.
@@ -1711,6 +1721,8 @@ def stream_parameters(streams, no_duplicates=True, exclude=['name', '_memoize_ke
     If no_duplicates is enabled, a KeyError will be raised if there are
     parameter name clashes across the streams.
     """
+    if exclude is None:
+        exclude = ['name', '_memoize_key']
     from ..streams import Params
     param_groups = {}
     for s in streams:
diff --git a/holoviews/element/__init__.py b/holoviews/element/__init__.py
index 43482ff454..3d05f594df 100644
--- a/holoviews/element/__init__.py
+++ b/holoviews/element/__init__.py
@@ -35,7 +35,9 @@ def curve(self, kdims=None, vdims=None, groupby=None, **kwargs):
     def errorbars(self, kdims=None, vdims=None, groupby=None, **kwargs):
         return self(ErrorBars, kdims, vdims, groupby, **kwargs)
 
-    def distribution(self, dim=None, groupby=[], **kwargs):
+    def distribution(self, dim=None, groupby=None, **kwargs):
+        if groupby is None:
+            groupby = []
         if dim is None:
             if self._element.vdims:
                 dim = self._element.vdims[0]
diff --git a/holoviews/element/raster.py b/holoviews/element/raster.py
index 7850ba3437..0d5eaa8242 100644
--- a/holoviews/element/raster.py
+++ b/holoviews/element/raster.py
@@ -101,7 +101,7 @@ def dimension_values(self, dim, expanded=True, flat=True):
         else:
             return super().dimension_values(dim)
 
-    def sample(self, samples=[], bounds=None, **sample_values):
+    def sample(self, samples=None, bounds=None, **sample_values):
         """
         Sample the Raster along one or both of its dimensions,
         returning a reduced dimensionality type, which is either
@@ -110,6 +110,8 @@ def sample(self, samples=[], bounds=None, **sample_values):
         of the sampled unit indexed by the value in the new_xaxis
         tuple.
         """
+        if samples is None:
+            samples = []
         if isinstance(samples, tuple):
             X, Y = samples
             samples = zip(X, Y)
@@ -452,13 +454,15 @@ def select(self, selection_specs=None, **selection):
                               ydensity=self.ydensity, bounds=bounds)
 
 
-    def closest(self, coords=[], **kwargs):
+    def closest(self, coords=None, **kwargs):
         """
         Given a single coordinate or multiple coordinates as
         a tuple or list of tuples or keyword arguments matching
         the dimension closest will find the closest actual x/y
         coordinates.
         """
+        if coords is None:
+            coords = []
         if kwargs and coords:
             raise ValueError("Specify coordinate using as either a list "
                              "keyword arguments not both")
diff --git a/holoviews/element/tabular.py b/holoviews/element/tabular.py
index b0c333e0ed..f2b82a46ab 100644
--- a/holoviews/element/tabular.py
+++ b/holoviews/element/tabular.py
@@ -71,7 +71,9 @@ def dimension_values(self, dimension, expanded=True, flat=True):
         else:
             return super().dimension_values(dimension)
 
-    def sample(self, samples=[]):
+    def sample(self, samples=None):
+        if samples is None:
+            samples = []
         if callable(samples):
             sampled_data = OrderedDict(item for item in self.data.items()
                                        if samples(item))
diff --git a/holoviews/ipython/archive.py b/holoviews/ipython/archive.py
index b506a772ad..e607db9d00 100644
--- a/holoviews/ipython/archive.py
+++ b/holoviews/ipython/archive.py
@@ -156,8 +156,10 @@ def export(self, timestamp=None):
         display(Javascript(cmd))
 
 
-    def add(self, obj=None, filename=None, data=None, info={}, html=None):
+    def add(self, obj=None, filename=None, data=None, info=None, html=None):
         "Similar to FileArchive.add but accepts html strings for substitution"
+        if info is None:
+            info = {}
         initial_last_key = list(self._files.keys())[-1] if len(self) else None
         if self._auto:
             exporters = self.exporters[:]
diff --git a/holoviews/operation/element.py b/holoviews/operation/element.py
index 58cde6da18..f4f45ea555 100644
--- a/holoviews/operation/element.py
+++ b/holoviews/operation/element.py
@@ -1069,9 +1069,11 @@ def __call__(self, data, **params):
             return GridMatrix(data)
 
 
-    def _process(self, p, element, ranges={}):
+    def _process(self, p, element, ranges=None):
         # Creates a unified Dataset.data attribute
         # to draw the data from
+        if ranges is None:
+            ranges = {}
         if isinstance(element.data, np.ndarray):
             el_data = element.table(default_datatype)
         else:
diff --git a/holoviews/operation/normalization.py b/holoviews/operation/normalization.py
index 16d94b92e9..1a46e44105 100644
--- a/holoviews/operation/normalization.py
+++ b/holoviews/operation/normalization.py
@@ -79,12 +79,16 @@ class Normalization(Operation):
        normalization.""")
 
 
-    def __call__(self, element, ranges={}, keys=None, **params):
+    def __call__(self, element, ranges=None, keys=None, **params):
+        if ranges is None:
+            ranges = {}
         params = dict(params,ranges=ranges, keys=keys)
         return super().__call__(element, **params)
 
 
-    def process_element(self, element, key, ranges={}, keys=None, **params):
+    def process_element(self, element, key, ranges=None, keys=None, **params):
+        if ranges is None:
+            ranges = {}
         params = dict(params,ranges=ranges, keys=keys)
         self.p = param.ParamOverrides(self, params)
         return self._process(element, key)
diff --git a/holoviews/plotting/bokeh/chart.py b/holoviews/plotting/bokeh/chart.py
index 6165b17c12..b484a7feef 100644
--- a/holoviews/plotting/bokeh/chart.py
+++ b/holoviews/plotting/bokeh/chart.py
@@ -786,7 +786,9 @@ class BarPlot(BarsMixin, ColorbarPlot, LegendPlot):
     _y_range_type = Range1d
 
     def _axis_properties(self, axis, key, plot, dimension=None,
-                         ax_mapping={'x': 0, 'y': 1}):
+                         ax_mapping=None):
+        if ax_mapping is None:
+            ax_mapping = {"x": 0, "y": 1}
         props = super()._axis_properties(axis, key, plot, dimension, ax_mapping)
         if (not self.multi_level and not self.stacked and self.current_frame.ndims > 1 and
             ((not self.invert_axes and axis == 'x') or (self.invert_axes and axis =='y'))):
diff --git a/holoviews/plotting/bokeh/element.py b/holoviews/plotting/bokeh/element.py
index 9ef835d5a7..66ff9e5779 100644
--- a/holoviews/plotting/bokeh/element.py
+++ b/holoviews/plotting/bokeh/element.py
@@ -255,10 +255,12 @@ def _hover_opts(self, element):
         dims += element.dimensions()
         return list(util.unique_iterator(dims)), {}
 
-    def _init_tools(self, element, callbacks=[]):
+    def _init_tools(self, element, callbacks=None):
         """
         Processes the list of tools to be supplied to the plot.
         """
+        if callbacks is None:
+            callbacks = []
         tooltips, hover_opts = self._hover_opts(element)
         tooltips = [(ttp.pprint_label, '@{%s}' % util.dimension_sanitizer(ttp.name))
                     if isinstance(ttp, Dimension) else ttp for ttp in tooltips]
@@ -402,8 +404,10 @@ def _shared_axis_range(self, plots, specs, range_type, axis_type, pos):
         return dim_range
 
     def _axis_props(self, plots, subplots, element, ranges, pos, *, dim=None,
-                    range_tags_extras=[], extra_range_name=None):
+                    range_tags_extras=None, extra_range_name=None):
 
+        if range_tags_extras is None:
+            range_tags_extras = []
         el = element.traverse(lambda x: x, [lambda el: isinstance(el, Element) and not isinstance(el, (Annotation, Tiles))])
         el = el[0] if el else element
         if isinstance(el, Graph):
@@ -755,12 +759,14 @@ def _populate_axis_handles(self, plot):
         self.handles['extra_y_scales'] = plot.extra_y_scales
 
     def _axis_properties(self, axis, key, plot, dimension=None,
-                         ax_mapping={'x': 0, 'y': 1}):
+                         ax_mapping=None):
         """
         Returns a dictionary of axis properties depending
         on the specified axis.
         """
         # need to copy dictionary by calling dict() on it
+        if ax_mapping is None:
+            ax_mapping = {'x': 0, 'y': 1}
         axis_props = dict(theme_attr_json(self.renderer.theme, 'Axis'))
 
         if ((axis == 'x' and self.xaxis in ['bottom-bare', 'top-bare', 'bare']) or
@@ -2662,10 +2668,12 @@ def _process_legend(self, overlay):
                     r.muted = self.legend_muted or r.muted
 
 
-    def _init_tools(self, element, callbacks=[]):
+    def _init_tools(self, element, callbacks=None):
         """
         Processes the list of tools to be supplied to the plot.
         """
+        if callbacks is None:
+            callbacks = []
         hover_tools = {}
         init_tools, tool_types = [], []
         for key, subplot in self.subplots.items():
diff --git a/holoviews/plotting/bokeh/plot.py b/holoviews/plotting/bokeh/plot.py
index 9c936b901d..a1e1be1959 100644
--- a/holoviews/plotting/bokeh/plot.py
+++ b/holoviews/plotting/bokeh/plot.py
@@ -570,7 +570,9 @@ def _create_subplots(self, layout, ranges):
         return subplots, collapsed_layout
 
 
-    def initialize_plot(self, ranges=None, plots=[]):
+    def initialize_plot(self, ranges=None, plots=None):
+        if plots is None:
+            plots = []
         ranges = self.compute_ranges(self.layout, self.keys[-1], None)
         passed_plots = list(plots)
         plots = [[None for c in range(self.cols)] for r in range(self.rows)]
@@ -1045,7 +1047,7 @@ def __init__(self, layout, layout_type, subplots, **params):
         # The supplied (axes, view) objects as indexed by position
         super().__init__(subplots=subplots, **params)
 
-    def initialize_plot(self, ranges=None, plots=[]):
+    def initialize_plot(self, ranges=None, plots=None):
         """
         Plot all the views contained in the AdjointLayout Object using axes
         appropriate to the layout configuration. All the axes are
@@ -1053,6 +1055,8 @@ def initialize_plot(self, ranges=None, plots=[]):
         invoke subplots with correct options and styles and hide any
         empty axes as necessary.
         """
+        if plots is None:
+            plots = []
         if plots is None: plots = []
         adjoined_plots = []
         for pos in self.view_positions:
diff --git a/holoviews/plotting/bokeh/selection.py b/holoviews/plotting/bokeh/selection.py
index 5c2b6bd1bc..436c99a914 100644
--- a/holoviews/plotting/bokeh/selection.py
+++ b/holoviews/plotting/bokeh/selection.py
@@ -14,7 +14,9 @@ def _build_selection(self, el, exprs, **kwargs):
             opts['selected'] = list(np.where(mask)[0])
         return el.opts(clone=True, backend='bokeh', **opts)
 
-    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache={}):
+    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache=None):
+        if cache is None:
+            cache = {}
         sel_streams = [selection_streams.exprs_stream]
         hvobj = hvobj.apply(self._build_selection, streams=sel_streams, per_element=True)
         for op in operations:
diff --git a/holoviews/plotting/bokeh/util.py b/holoviews/plotting/bokeh/util.py
index 3d5557c9aa..40775bbdae 100644
--- a/holoviews/plotting/bokeh/util.py
+++ b/holoviews/plotting/bokeh/util.py
@@ -998,7 +998,7 @@ def date_to_integer(date):
     return dt_int
 
 
-def glyph_order(keys, draw_order=[]):
+def glyph_order(keys, draw_order=None):
     """
     Orders a set of glyph handles using regular sort and an explicit
     sort order. The explicit draw order must take the form of a list
@@ -1006,6 +1006,8 @@ def glyph_order(keys, draw_order=[]):
     suffix. The draw order may only match subset of the keys and any
     matched items will take precedence over other entries.
     """
+    if draw_order is None:
+        draw_order = []
     keys = sorted(keys)
     def order_fn(glyph):
         matches = [item for item in draw_order if glyph.startswith(item)]
diff --git a/holoviews/plotting/mpl/plot.py b/holoviews/plotting/mpl/plot.py
index f313e34a05..ba586dbdd3 100644
--- a/holoviews/plotting/mpl/plot.py
+++ b/holoviews/plotting/mpl/plot.py
@@ -1019,7 +1019,7 @@ def grid_situate(self, current_idx, layout_type, subgrid_width):
 
         return start, inds
 
-    def _create_subplots(self, layout, positions, layout_dimensions, ranges, axes={}, num=1, create=True):
+    def _create_subplots(self, layout, positions, layout_dimensions, ranges, axes=None, num=1, create=True):
         """
         Plot all the views contained in the AdjointLayout Object using axes
         appropriate to the layout configuration. All the axes are
@@ -1027,6 +1027,8 @@ def _create_subplots(self, layout, positions, layout_dimensions, ranges, axes={}
         invoke subplots with correct options and styles and hide any
         empty axes as necessary.
         """
+        if axes is None:
+            axes = {}
         subplots = {}
         projections = []
         adjoint_clone = layout.clone(shared_data=False, id=layout.id)
diff --git a/holoviews/plotting/mpl/util.py b/holoviews/plotting/mpl/util.py
index 6fd5662705..be7eb09f39 100644
--- a/holoviews/plotting/mpl/util.py
+++ b/holoviews/plotting/mpl/util.py
@@ -128,7 +128,7 @@ def validate(style, value, vectorized=True):
         return False
 
 
-def filter_styles(style, group, other_groups, blacklist=[]):
+def filter_styles(style, group, other_groups, blacklist=None):
     """
     Filters styles which are specific to a particular artist, e.g.
     for a GraphPlot this will filter options specific to the nodes and
@@ -150,6 +150,8 @@ def filter_styles(style, group, other_groups, blacklist=[]):
     filtered: dict
         Filtered dictionary of styles
     """
+    if blacklist is None:
+        blacklist = []
     group = group+'_'
     filtered = {}
     for k, v in style.items():
@@ -248,12 +250,14 @@ def resolve_rows(rows):
         return resolve_rows(merged_rows)
 
 
-def fix_aspect(fig, nrows, ncols, title=None, extra_artists=[],
+def fix_aspect(fig, nrows, ncols, title=None, extra_artists=None,
                vspace=0.2, hspace=0.2):
     """
     Calculate heights and widths of axes and adjust
     the size of the figure to match the aspect.
     """
+    if extra_artists is None:
+        extra_artists = []
     fig.canvas.draw()
     w, h = fig.get_size_inches()
 
@@ -288,10 +292,12 @@ def fix_aspect(fig, nrows, ncols, title=None, extra_artists=[],
             title.set_y(top/(w*aspect))
 
 
-def get_tight_bbox(fig, bbox_extra_artists=[], pad=None):
+def get_tight_bbox(fig, bbox_extra_artists=None, pad=None):
     """
     Compute a tight bounding box around all the artists in the figure.
     """
+    if bbox_extra_artists is None:
+        bbox_extra_artists = []
     renderer = fig.canvas.get_renderer()
     bbox_inches = fig.get_tightbbox(renderer)
     bbox_artists = bbox_extra_artists[:]
diff --git a/holoviews/plotting/plot.py b/holoviews/plotting/plot.py
index 29d60f51b0..9bf5831825 100644
--- a/holoviews/plotting/plot.py
+++ b/holoviews/plotting/plot.py
@@ -1170,7 +1170,11 @@ class GenericElementPlot(DimensionedPlot):
 
     def __init__(self, element, keys=None, ranges=None, dimensions=None,
                  batched=False, overlaid=0, cyclic_index=0, zorder=0, style=None,
-                 overlay_dims={}, stream_sources={}, streams=None, **params):
+                 overlay_dims=None, stream_sources=None, streams=None, **params):
+        if stream_sources is None:
+            stream_sources = {}
+        if overlay_dims is None:
+            overlay_dims = {}
         self.zorder = zorder
         self.cyclic_index = cyclic_index
         self.overlaid = overlaid
diff --git a/holoviews/plotting/renderer.py b/holoviews/plotting/renderer.py
index 7a2af71a1b..30da306a7c 100644
--- a/holoviews/plotting/renderer.py
+++ b/holoviews/plotting/renderer.py
@@ -558,12 +558,16 @@ def plot_options(cls, obj, percent_size):
         raise NotImplementedError
 
     @bothmethod
-    def save(self_or_cls, obj, basename, fmt='auto', key={}, info={},
+    def save(self_or_cls, obj, basename, fmt='auto', key=None, info=None,
              options=None, resources='inline', title=None, **kwargs):
         """
         Save a HoloViews object to file, either using an explicitly
         supplied format or to the appropriate default.
         """
+        if info is None:
+            info = {}
+        if key is None:
+            key = {}
         if info or key:
             raise Exception('Renderer does not support saving metadata to file.')
 
diff --git a/holoviews/plotting/util.py b/holoviews/plotting/util.py
index 48f82bef24..02bcab317a 100644
--- a/holoviews/plotting/util.py
+++ b/holoviews/plotting/util.py
@@ -120,7 +120,7 @@ def overlay_depth(obj):
         return 1
 
 
-def compute_overlayable_zorders(obj, path=[]):
+def compute_overlayable_zorders(obj, path=None):
     """
     Traverses an overlayable composite container to determine which
     objects are associated with specific (Nd)Overlay layers by
@@ -131,6 +131,8 @@ def compute_overlayable_zorders(obj, path=[]):
     Used to determine which overlaid subplots should be linked with
     Stream callbacks.
     """
+    if path is None:
+        path = []
     path = path+[obj]
     zorder_map = defaultdict(list)
 
diff --git a/holoviews/selection.py b/holoviews/selection.py
index 628ead0d33..ea5ae96bbb 100644
--- a/holoviews/selection.py
+++ b/holoviews/selection.py
@@ -475,11 +475,15 @@ class SelectionDisplay:
     def __call__(self, element):
         return self
 
-    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache={}):
+    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache=None):
+        if cache is None:
+            cache = {}
         raise NotImplementedError()
 
     @staticmethod
-    def _select(element, selection_expr, cache={}):
+    def _select(element, selection_expr, cache=None):
+        if cache is None:
+            cache = {}
         from .element import Curve, Spread
         from .util.transform import dim
         if isinstance(selection_expr, dim):
@@ -646,7 +650,9 @@ def __init__(self, color_prop='color', alpha_prop='alpha', backend=None):
         self.alpha_props = [alpha_prop]
         self.backend = backend
 
-    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache={}):
+    def build_selection(self, selection_streams, hvobj, operations, region_stream=None, cache=None):
+        if cache is None:
+            cache = {}
         def _build_selection(el, colors, alpha, exprs, **kwargs):
             from .plotting.util import linear_gradient
             ds = el.dataset
diff --git a/holoviews/streams.py b/holoviews/streams.py
index fb4877ff15..69ff448609 100644
--- a/holoviews/streams.py
+++ b/holoviews/streams.py
@@ -241,7 +241,7 @@ def _process_streams(cls, streams):
         return valid, invalid
 
 
-    def __init__(self, rename={}, source=None, subscribers=[], linked=False,
+    def __init__(self, rename=None, source=None, subscribers=None, linked=False,
                  transient=False, **params):
         """
         The rename argument allows multiple streams with similar event
@@ -256,6 +256,10 @@ def __init__(self, rename={}, source=None, subscribers=[], linked=False,
         """
 
         # Source is stored as a weakref to allow it to be garbage collected
+        if subscribers is None:
+            subscribers = []
+        if rename is None:
+            rename = {}
         self._source = None if source is None else weakref.ref(source)
 
         self._subscribers = []
@@ -1603,7 +1607,9 @@ class PointDraw(CDSStream):
         path-like data).""")
 
     def __init__(self, empty_value=None, add=True, drag=True, num_objects=0,
-                 styles={}, tooltip=None, **params):
+                 styles=None, tooltip=None, **params):
+        if styles is None:
+            styles = {}
         self.add = add
         self.drag = drag
         self.empty_value = empty_value
@@ -1646,7 +1652,9 @@ class CurveEdit(PointDraw):
         (for point-like data) or list of lists of values (for
         path-like data).""")
 
-    def __init__(self, style={}, tooltip=None, **params):
+    def __init__(self, style=None, tooltip=None, **params):
+        if style is None:
+            style = {}
         self.style = style or {'size': 10}
         self.tooltip = tooltip
         super(PointDraw, self).__init__(**params)
@@ -1690,8 +1698,12 @@ class PolyDraw(CDSStream):
         path-like data).""")
 
     def __init__(self, empty_value=None, drag=True, num_objects=0,
-                 show_vertices=False, vertex_style={}, styles={},
+                 show_vertices=False, vertex_style=None, styles=None,
                  tooltip=None, **params):
+        if styles is None:
+            styles = {}
+        if vertex_style is None:
+            vertex_style = {}
         self.drag = drag
         self.empty_value = empty_value
         self.num_objects = num_objects
@@ -1748,7 +1760,9 @@ class FreehandDraw(CDSStream):
         (for point-like data) or list of lists of values (for
         path-like data).""")
 
-    def __init__(self, empty_value=None, num_objects=0, styles={}, tooltip=None, **params):
+    def __init__(self, empty_value=None, num_objects=0, styles=None, tooltip=None, **params):
+        if styles is None:
+            styles = {}
         self.empty_value = empty_value
         self.num_objects = num_objects
         self.styles = styles
@@ -1802,7 +1816,9 @@ class BoxEdit(CDSStream):
         (for point-like data) or list of lists of values (for
         path-like data).""")
 
-    def __init__(self, empty_value=None, num_objects=0, styles={}, tooltip=None, **params):
+    def __init__(self, empty_value=None, num_objects=0, styles=None, tooltip=None, **params):
+        if styles is None:
+            styles = {}
         self.empty_value = empty_value
         self.num_objects = num_objects
         self.styles = styles
@@ -1864,6 +1880,8 @@ class PolyEdit(PolyDraw):
         (for point-like data) or list of lists of values (for
         path-like data).""")
 
-    def __init__(self, vertex_style={}, shared=True, **params):
+    def __init__(self, vertex_style=None, shared=True, **params):
+        if vertex_style is None:
+            vertex_style = {}
         self.shared = shared
         super().__init__(vertex_style=vertex_style, **params)
diff --git a/holoviews/tests/core/test_dimensioned.py b/holoviews/tests/core/test_dimensioned.py
index dbd4743bc9..de4688b5ae 100644
--- a/holoviews/tests/core/test_dimensioned.py
+++ b/holoviews/tests/core/test_dimensioned.py
@@ -40,7 +40,11 @@ def tearDown(self):
         Store.renderers.pop('backend_2')
 
     @classmethod
-    def register_custom(cls, objtype, backend, custom_plot=[], custom_style=[]):
+    def register_custom(cls, objtype, backend, custom_plot=None, custom_style=None):
+        if custom_style is None:
+            custom_style = []
+        if custom_plot is None:
+            custom_plot = []
         groups = Options._option_groups
         if backend not in Store._options:
             Store._options[backend] = OptionTree([], groups=groups)
diff --git a/holoviews/tests/plotting/bokeh/test_plot.py b/holoviews/tests/plotting/bokeh/test_plot.py
index aa0e04fa84..d7496bdae6 100644
--- a/holoviews/tests/plotting/bokeh/test_plot.py
+++ b/holoviews/tests/plotting/bokeh/test_plot.py
@@ -59,7 +59,9 @@ def _test_colormapping(self, element, dim, log=False):
         mapper_type = LogColorMapper if log else LinearColorMapper
         self.assertTrue(isinstance(cmapper, mapper_type))
 
-    def _test_hover_info(self, element, tooltips, line_policy='nearest', formatters={}):
+    def _test_hover_info(self, element, tooltips, line_policy='nearest', formatters=None):
+        if formatters is None:
+            formatters = {}
         plot = bokeh_renderer.get_plot(element)
         plot.initialize_plot()
         fig = plot.state
diff --git a/holoviews/util/__init__.py b/holoviews/util/__init__.py
index a22434a902..3961ade353 100644
--- a/holoviews/util/__init__.py
+++ b/holoviews/util/__init__.py
@@ -991,7 +991,9 @@ def _get_streams(self, map_obj, watch=True):
             raise TypeError(msg.format(objs = ', '.join(f'{el!r}' for el in invalid)))
         return valid
 
-    def _process(self, element, key=None, kwargs={}):
+    def _process(self, element, key=None, kwargs=None):
+        if kwargs is None:
+            kwargs = {}
         if util.is_param_method(self.p.operation) and util.get_method_owner(self.p.operation) is element:
             return self.p.operation(**kwargs)
         elif isinstance(self.p.operation, Operation):
diff --git a/holoviews/util/parser.py b/holoviews/util/parser.py
index 437289e8d6..b2bab3c6f5 100644
--- a/holoviews/util/parser.py
+++ b/holoviews/util/parser.py
@@ -78,7 +78,7 @@ def collect_tokens(cls, parseresult, mode):
         return tokens
 
     @classmethod
-    def todict(cls, parseresult, mode='parens', ns={}):
+    def todict(cls, parseresult, mode='parens', ns=None):
         """
         Helper function to return dictionary given the parse results
         from a pyparsing.nestedExpr object (containing keywords).
@@ -86,6 +86,8 @@ def todict(cls, parseresult, mode='parens', ns={}):
         The ns is a dynamic namespace (typically the IPython Notebook
         namespace) used to update the class-level namespace.
         """
+        if ns is None:
+            ns = {}
         grouped, kwargs = [], {}
         tokens = cls.collect_tokens(parseresult, mode)
         # Group tokens without '=' and append to last token containing '='
@@ -299,11 +301,13 @@ def apply_deprecations(cls, path):
 
 
     @classmethod
-    def parse(cls, line, ns={}):
+    def parse(cls, line, ns=None):
         """
         Parse an options specification, returning a dictionary with
         path keys and {'plot':<options>, 'style':<options>} values.
         """
+        if ns is None:
+            ns = {}
         parses  = [p for p in cls.opts_spec.scanString(line)]
         if len(parses) != 1:
             raise SyntaxError("Invalid specification syntax.")
@@ -344,11 +348,13 @@ def parse(cls, line, ns={}):
         }
 
     @classmethod
-    def parse_options(cls, line, ns={}):
+    def parse_options(cls, line, ns=None):
         """
         Similar to parse but returns a list of Options objects instead
         of the dictionary format.
         """
+        if ns is None:
+            ns = {}
         parsed = cls.parse(line, ns=ns)
         options_list = []
         for spec in sorted(parsed.keys()):
@@ -400,10 +406,12 @@ class CompositorSpec(Parser):
 
 
     @classmethod
-    def parse(cls, line, ns={}):
+    def parse(cls, line, ns=None):
         """
         Parse compositor specifications, returning a list Compositors
         """
+        if ns is None:
+            ns = {}
         definitions = []
         parses  = [p for p in cls.compositor_spec.scanString(line)]
         if len(parses) != 1:
diff --git a/holoviews/util/transform.py b/holoviews/util/transform.py
index 9ab375bb7a..5681517dcc 100644
--- a/holoviews/util/transform.py
+++ b/holoviews/util/transform.py
@@ -689,7 +689,7 @@ def _coerce(self, data):
         """
         return data
 
-    def apply(self, dataset, flat=False, expanded=None, ranges={}, all_values=False,
+    def apply(self, dataset, flat=False, expanded=None, ranges=None, all_values=False,
               keep_index=False, compute=True, strict=False):
         """Evaluates the transform on the supplied dataset.
 
@@ -712,6 +712,8 @@ def apply(self, dataset, flat=False, expanded=None, ranges={}, all_values=False,
         Returns:
             values: NumPy array computed by evaluating the expression
         """
+        if ranges is None:
+            ranges = {}
         from ..element import Graph
 
         dimension = self.dimension

From bdb519a26ab1f3bcca311c8c3542f4853b0cc468 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 08:50:51 +0200
Subject: [PATCH 03/11] B006 - Manual fix mutable argument

---
 holoviews/tests/core/test_dynamic.py          | 21 ++++++++++++-------
 .../tests/plotting/bokeh/test_callbacks.py    |  3 ++-
 .../plotting/matplotlib/test_callbacks.py     |  3 ++-
 .../tests/plotting/plotly/test_elementplot.py |  3 ++-
 holoviews/util/command.py                     |  9 ++++----
 5 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/holoviews/tests/core/test_dynamic.py b/holoviews/tests/core/test_dynamic.py
index 8d043b0fa5..8363f99453 100644
--- a/holoviews/tests/core/test_dynamic.py
+++ b/holoviews/tests/core/test_dynamic.py
@@ -389,7 +389,8 @@ def test_deep_map_apply_dmap_function_no_clone(self):
         self.assertIs(mapped, layout)
 
     def test_dynamic_reindex_reorder(self):
-        def history_callback(x, y, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x, y):
             history.append((x, y))
             return Points(list(history))
         dmap = DynamicMap(history_callback, kdims=['x', 'y'])
@@ -398,7 +399,8 @@ def history_callback(x, y, history=deque(maxlen=10)):
         self.assertEqual(points, Points([(1, 2)]))
 
     def test_dynamic_reindex_drop_raises_exception(self):
-        def history_callback(x, y, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x, y):
             history.append((x, y))
             return Points(list(history))
         dmap = DynamicMap(history_callback, kdims=['x', 'y'])
@@ -790,7 +792,8 @@ def test_dynamic_keydim_memoize_disable(self):
 
     def test_dynamic_callable_memoize(self):
         # Always memoized only one of each held
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             history.append(x)
             return Curve(list(history))
 
@@ -812,7 +815,8 @@ def history_callback(x, history=deque(maxlen=10)):
     def test_dynamic_callable_disable_callable_memoize(self):
         # Disabling Callable.memoize means no memoization is applied,
         # every access to DynamicMap calls callback and adds sample
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             history.append(x)
             return Curve(list(history))
 
@@ -878,7 +882,8 @@ def test_dynamic_callable_stream_transient(self):
         # Enable transient stream meaning memoization only happens when
         # stream is inactive, should have sample for each call to
         # stream.update
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             if x is not None:
                 history.append(x)
             return Curve(list(history))
@@ -900,7 +905,8 @@ def history_callback(x, history=deque(maxlen=10)):
     def test_dynamic_stream_transients(self):
         # Ensure Stream reset option resets streams to default value
         # when not triggering
-        def history_callback(x, y, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x, y):
             if x is None:
                 history_callback.xresets += 1
             else:
@@ -933,7 +939,8 @@ def test_dynamic_callable_stream_hashkey(self):
         # Enable transient stream meaning memoization only happens when
         # stream is inactive, should have sample for each call to
         # stream.update
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             if x is not None:
                 history.append(x)
             return Curve(list(history))
diff --git a/holoviews/tests/plotting/bokeh/test_callbacks.py b/holoviews/tests/plotting/bokeh/test_callbacks.py
index 68e868a1b7..bb0810ab67 100644
--- a/holoviews/tests/plotting/bokeh/test_callbacks.py
+++ b/holoviews/tests/plotting/bokeh/test_callbacks.py
@@ -98,7 +98,8 @@ def test_stream_callback_with_ids(self):
         self.assertEqual(data['y'], np.array([0.4]))
 
     def test_stream_callback_single_call(self):
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             history.append(x)
             return Curve(list(history))
         stream = PointerX(x=0)
diff --git a/holoviews/tests/plotting/matplotlib/test_callbacks.py b/holoviews/tests/plotting/matplotlib/test_callbacks.py
index 7214704aba..2c7fe2cddf 100644
--- a/holoviews/tests/plotting/matplotlib/test_callbacks.py
+++ b/holoviews/tests/plotting/matplotlib/test_callbacks.py
@@ -24,7 +24,8 @@ def test_dynamic_streams_refresh(self):
         self.assertNotEqual(pre, post)
 
     def test_stream_callback_single_call(self):
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             history.append(x)
             return Curve(list(history))
         stream = PointerX(x=0)
diff --git a/holoviews/tests/plotting/plotly/test_elementplot.py b/holoviews/tests/plotting/plotly/test_elementplot.py
index 5f1460c6b1..e3b589fd26 100644
--- a/holoviews/tests/plotting/plotly/test_elementplot.py
+++ b/holoviews/tests/plotting/plotly/test_elementplot.py
@@ -13,7 +13,8 @@
 class TestElementPlot(TestPlotlyPlot):
 
     def test_stream_callback_single_call(self):
-        def history_callback(x, history=deque(maxlen=10)):
+        history = deque(maxlen=10)
+        def history_callback(x):
             history.append(x)
             return Curve(list(history))
         stream = PointerX(x=0)
diff --git a/holoviews/util/command.py b/holoviews/util/command.py
index 6751142bcc..da73b4165a 100755
--- a/holoviews/util/command.py
+++ b/holoviews/util/command.py
@@ -25,6 +25,7 @@
 
 from . import examples
 
+_PREPROCESSORS = [OptsMagicProcessor(), OutputMagicProcessor(), StripMagicsProcessor()]
 
 def main():
     if len(sys.argv) < 2:
@@ -56,11 +57,9 @@ def main():
         examples(path=examples_dir, root=root)
 
 
-def export_to_python(filename=None,
-         preprocessors=[OptsMagicProcessor(),
-                        OutputMagicProcessor(),
-                        StripMagicsProcessor()]):
-
+def export_to_python(filename=None, preprocessors=None):
+    if preprocessors is None:
+        preprocessors = _PREPROCESSORS.copy()
     filename = filename if filename else sys.argv[1]
     with open(filename) as f:
         nb = nbformat.read(f, nbformat.NO_CONVERT)

From a0d601d9f52c692aeb0fb921d096c5cfa93dcc08 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 08:59:39 +0200
Subject: [PATCH 04/11] Fix self.assertRaises(Exception)

---
 holoviews/tests/plotting/matplotlib/test_graphplot.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/holoviews/tests/plotting/matplotlib/test_graphplot.py b/holoviews/tests/plotting/matplotlib/test_graphplot.py
index b370b95ebb..22aa1bf85b 100644
--- a/holoviews/tests/plotting/matplotlib/test_graphplot.py
+++ b/holoviews/tests/plotting/matplotlib/test_graphplot.py
@@ -401,7 +401,8 @@ def test_trimesh_op_node_alpha(self):
 
         if Version(mpl.__version__) < Version("3.4.0"):
             # Python 3.6 only support up to matplotlib 3.3
-            with self.assertRaises(Exception):
+            msg = "TypeError: alpha must be a float or None"
+            with pytest.raises(AbbreviatedException, match=msg):
                 mpl_renderer.get_plot(trimesh)
         else:
             plot = mpl_renderer.get_plot(trimesh)

From 3a5fe49fd77cb6363b14310c0cbb8ab8f6e806aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 09:07:52 +0200
Subject: [PATCH 05/11] B018 - Fix useless expression, by making it a function
 call to be more explicit

---
 holoviews/element/graphs.py        | 13 +++++++++----
 holoviews/plotting/bokeh/graphs.py |  2 +-
 holoviews/plotting/mpl/graphs.py   |  3 +--
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/holoviews/element/graphs.py b/holoviews/element/graphs.py
index 781100a873..2935ff93e7 100644
--- a/holoviews/element/graphs.py
+++ b/holoviews/element/graphs.py
@@ -552,8 +552,7 @@ def from_vertices(cls, data):
         tris = Delaunay(data.array([0, 1]))
         return cls((tris.simplices, data))
 
-    @property
-    def edgepaths(self):
+    def _initialize_edgepaths(self):
         """
         Returns the EdgePaths by generating a triangle for each simplex.
         """
@@ -576,6 +575,13 @@ def edgepaths(self):
         self._edgepaths = edgepaths
         return edgepaths
 
+    @property
+    def edgepaths(self):
+        """
+        Returns the EdgePaths by generating a triangle for each simplex.
+        """
+        return self._initialize_edgepaths()
+
     def select(self, selection_specs=None, **selection):
         """
         Allows selecting data by the slices, sets and scalar values
@@ -586,8 +592,7 @@ def select(self, selection_specs=None, **selection):
         supplied, which will ensure the selection is only applied if the
         specs match the selected object.
         """
-        # Ensure that edgepaths are initialized so they can be selected on
-        self.edgepaths
+        self._initialize_edgepaths()
         return super().select(selection_specs=None,
                               selection_mode='nodes',
                               **selection)
diff --git a/holoviews/plotting/bokeh/graphs.py b/holoviews/plotting/bokeh/graphs.py
index 4f6924b07e..bf9bfd898e 100644
--- a/holoviews/plotting/bokeh/graphs.py
+++ b/holoviews/plotting/bokeh/graphs.py
@@ -507,7 +507,7 @@ def _process_vertices(self, element):
             z = element.nodes.dimension_values(vertex_dim)
             z = z[simplices].mean(axis=1)
             element = element.add_dimension(vertex_dim, len(element.vdims), z, vdim=True)
-        element.edgepaths
+        element._initialize_edgepaths()
         return element
 
     def _init_glyphs(self, plot, element, ranges, source):
diff --git a/holoviews/plotting/mpl/graphs.py b/holoviews/plotting/mpl/graphs.py
index cab4288583..1609428e2a 100644
--- a/holoviews/plotting/mpl/graphs.py
+++ b/holoviews/plotting/mpl/graphs.py
@@ -245,8 +245,7 @@ def get_data(self, element, ranges, style):
             z = element.nodes.dimension_values(vertex_dim)
             z = z[simplices].mean(axis=1)
             element = element.add_dimension(vertex_dim, len(element.vdims), z, vdim=True)
-        # Ensure the edgepaths for the triangles are generated before plotting
-        element.edgepaths
+        element._initialize_edgepaths()
         return super().get_data(element, ranges, style)
 
 

From e51198faebb153440d5941ce6ca8bc14eb7cfefc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 09:13:26 +0200
Subject: [PATCH 06/11] Add Bugbear to Ruff

---
 pyproject.toml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pyproject.toml b/pyproject.toml
index e6307aa6da..783f30af4b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,6 +35,7 @@ run.concurrency = ["greenlet"]
 target-version = "py38"
 
 select = [
+    "B",
     "E",
     "F",
     "FLY",
@@ -51,6 +52,7 @@ select = [
 ]
 
 ignore = [
+    "B904",     # Within an `except` clause, raise exceptions with from err or None
     "E402",     # Module level import not at top of file
     "E501",     # Line too long
     "E701",     # Multiple statements on one line

From c1dc5b596e544882d256b2eaddb4dd6302eb9d55 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 18 Aug 2023 09:14:49 +0200
Subject: [PATCH 07/11] Ignore valid code

---
 holoviews/core/util.py               | 2 +-
 holoviews/tests/core/test_options.py | 7 +++----
 holoviews/tests/core/test_tree.py    | 7 +++++--
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/holoviews/core/util.py b/holoviews/core/util.py
index e5881a22a5..d78aa52ff0 100644
--- a/holoviews/core/util.py
+++ b/holoviews/core/util.py
@@ -1209,7 +1209,7 @@ def python2sort(x,key=None):
             try:
                 item_precedence = item if key is None else key(item)
                 group_precedence = group[0] if key is None else key(group[0])
-                item_precedence < group_precedence  # exception if not comparable
+                item_precedence < group_precedence  # noqa: B015, TypeError if not comparable
                 group.append(item)
                 break
             except TypeError:
diff --git a/holoviews/tests/core/test_options.py b/holoviews/tests/core/test_options.py
index 06ecbf5558..ceac1ce5e9 100644
--- a/holoviews/tests/core/test_options.py
+++ b/holoviews/tests/core/test_options.py
@@ -182,10 +182,9 @@ def test_cyclic_property_false(self):
     def test_options_property_disabled(self):
         cycle1 = Cycle(values=['a', 'b', 'c'])
         opts = Options('test', one=cycle1)
-        try:
-            opts.options
-        except Exception as e:
-            self.assertEqual(str(e), "The options property may only be used with non-cyclic Options.")
+        msg = r"The options property may only be used with non-cyclic Options\."
+        with pytest.raises(Exception, match=msg):
+            opts.options  # noqa: B018
 
 
 
diff --git a/holoviews/tests/core/test_tree.py b/holoviews/tests/core/test_tree.py
index 57f5c0a610..7b2c707944 100644
--- a/holoviews/tests/core/test_tree.py
+++ b/holoviews/tests/core/test_tree.py
@@ -1,3 +1,5 @@
+import pytest
+
 from holoviews.core.element import AttrTree
 from holoviews.element.comparison import ComparisonTestCase
 
@@ -24,8 +26,9 @@ def test_deep_setattr(self):
         self.assertEqual(self.tree.C.I, 3)
 
     def test_lowercase_attribute_error(self):
-        with self.assertRaises(AttributeError):
-            self.tree.c
+        msg = r"'AttrTree' object has no attribute c\."
+        with pytest.raises(AttributeError, match=msg):
+            self.tree.c  # noqa: B018
 
     def test_number_getitem_key_error(self):
         with self.assertRaises(KeyError):

From 31136af8e77053df013071d937c5f58e9e55e600 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Mon, 28 Aug 2023 11:54:58 +0200
Subject: [PATCH 08/11] Move import to top

---
 holoviews/core/accessors.py | 5 +++--
 holoviews/core/data/ibis.py | 2 +-
 holoviews/util/transform.py | 3 ++-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/holoviews/core/accessors.py b/holoviews/core/accessors.py
index 32c3a91e2a..7e742394f7 100644
--- a/holoviews/core/accessors.py
+++ b/holoviews/core/accessors.py
@@ -132,14 +132,15 @@ def __call__(self, apply_function, streams=None, link_inputs=True,
             A new object where the function was applied to all
             contained (Nd)Overlay or Element objects.
         """
-        if streams is None:
-            streams = []
         from .data import Dataset
         from .dimension import ViewableElement
         from .element import Element
         from .spaces import HoloMap, DynamicMap
         from ..util import Dynamic
 
+        if streams is None:
+            streams = []
+
         if isinstance(self._obj, DynamicMap) and dynamic == False:
             samples = tuple(d.values for d in self._obj.kdims)
             if not all(samples):
diff --git a/holoviews/core/data/ibis.py b/holoviews/core/data/ibis.py
index 1b62701e09..0a7022f8c8 100644
--- a/holoviews/core/data/ibis.py
+++ b/holoviews/core/data/ibis.py
@@ -417,9 +417,9 @@ def select_mask(cls, dataset, selection):
 
     @classmethod
     def sample(cls, dataset, samples=None):
+        import ibis
         if samples is None:
             samples = []
-        import ibis
         dims = dataset.dimensions()
         data = dataset.data
         if all(util.isscalar(s) or len(s) == 1 for s in samples):
diff --git a/holoviews/util/transform.py b/holoviews/util/transform.py
index 5681517dcc..c7b9bd1d7f 100644
--- a/holoviews/util/transform.py
+++ b/holoviews/util/transform.py
@@ -712,9 +712,10 @@ def apply(self, dataset, flat=False, expanded=None, ranges=None, all_values=Fals
         Returns:
             values: NumPy array computed by evaluating the expression
         """
+        from ..element import Graph
+
         if ranges is None:
             ranges = {}
-        from ..element import Graph
 
         dimension = self.dimension
         if expanded is None:

From 1690af93bbf955bf659ade2d9cf9f47d6fb4a033 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Tue, 29 Aug 2023 08:53:33 +0200
Subject: [PATCH 09/11] Convert v to _ in split_dmap_overlay

---
 holoviews/plotting/util.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/holoviews/plotting/util.py b/holoviews/plotting/util.py
index 02bcab317a..a78994b54c 100644
--- a/holoviews/plotting/util.py
+++ b/holoviews/plotting/util.py
@@ -225,14 +225,14 @@ def split_dmap_overlay(obj, depth=0):
     if isinstance(obj, DynamicMap):
         initialize_dynamic(obj)
         if issubclass(obj.type, NdOverlay) and not depth:
-            for v in obj.last.values():
+            for _ in obj.last.values():
                 layers.append(obj)
         elif issubclass(obj.type, Overlay):
             if obj.callback.inputs and is_dynamic_overlay(obj):
                 for inp in obj.callback.inputs:
                     layers += split_dmap_overlay(inp, depth+1)
             else:
-                for v in obj.last.values():
+                for _ in obj.last.values():
                     layers.append(obj)
         else:
             layers.append(obj)

From 79254680e5d20fe3e0da38454c592cbf3e869efc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 8 Sep 2023 13:59:56 +0200
Subject: [PATCH 10/11] Move import to top

---
 holoviews/core/accessors.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/holoviews/core/accessors.py b/holoviews/core/accessors.py
index 7e742394f7..ea167e7930 100644
--- a/holoviews/core/accessors.py
+++ b/holoviews/core/accessors.py
@@ -365,11 +365,12 @@ def _transform_dimension(self, kdims, vdims, dimension):
         return dimension
 
     def _create_expression_transform(self, kdims, vdims, exclude=None):
-        if exclude is None:
-            exclude = []
         from .dimension import dimension_name
         from ..util.transform import dim
 
+        if exclude is None:
+            exclude = []
+
         def _transform_expression(expression):
             if dimension_name(expression.dimension) in exclude:
                 dimension = expression.dimension

From 3163a6acdfaf5d881b620e1eaa2a7145b2630391 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20H=C3=B8xbro=20Hansen?= <simon.hansen@me.com>
Date: Fri, 22 Sep 2023 12:16:38 +0200
Subject: [PATCH 11/11] Remove star unpack after keyword argument

---
 holoviews/core/overlay.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/holoviews/core/overlay.py b/holoviews/core/overlay.py
index 39eebb244e..050b14a4cb 100644
--- a/holoviews/core/overlay.py
+++ b/holoviews/core/overlay.py
@@ -287,11 +287,10 @@ def ddims(self):
     def shape(self):
         raise NotImplementedError
 
-    def clone(self, data=None, shared_data=True, new_type=None, link=True,
-              *args, **overrides):
+    def clone(self, data=None, shared_data=True, new_type=None, link=True, **overrides):
         if data is None and link:
             overrides['plot_id'] = self._plot_id
-        return super().clone(data, shared_data=shared_data, new_type=new_type, link=link, *args, **overrides)
+        return super().clone(data, shared_data=shared_data, new_type=new_type, link=link, **overrides)
 
 
 class NdOverlay(Overlayable, UniformNdMapping, CompositeOverlay):