fix: import scanpy default palettes across scanpy versions (1.13 compat) (#759)

Author: timtreis

src/spatialdata_plot/pl/_color.py

@@ -29,7 +29,6 @@
 from pandas.api.types import CategoricalDtype, is_bool_dtype, is_numeric_dtype, is_string_dtype
 from pandas.core.arrays.categorical import Categorical
 from scanpy.plotting._utils import add_colors_for_categorical_sample_annotation
-from scanpy.plotting.palettes import default_20, default_28, default_102
 from skimage.color import label2rgb
 from skimage.morphology import erosion, footprint_rectangle
 from skimage.util import map_array
@@ -43,6 +42,7 @@
 )
 
 from spatialdata_plot._logging import logger
+from spatialdata_plot.pl._scanpy_palettes import default_20, default_28, default_102
 from spatialdata_plot.pl.render_params import (
     CmapParams,
     Color,

src/spatialdata_plot/pl/_palette.py

@@ -20,7 +20,8 @@
 import pandas as pd
 from matplotlib.colors import ListedColormap, to_hex, to_rgb
 from matplotlib.pyplot import colormaps as mpl_colormaps
-from scanpy.plotting.palettes import default_20, default_28, default_102
+
+from spatialdata_plot.pl._scanpy_palettes import default_20, default_28, default_102
 
 if TYPE_CHECKING:
     import spatialdata as sd

src/spatialdata_plot/pl/_scanpy_palettes.py

@@ -0,0 +1,14 @@
+"""Access scanpy's built-in categorical palettes across scanpy versions.
+
+scanpy relocated the ``default_20`` / ``default_28`` / ``default_102`` palettes from
+``scanpy.plotting.palettes`` to ``scanpy.plotting.legacy.palettes`` in 1.13. The values are
+frozen (identical across versions), so we import from whichever path the installed scanpy
+exposes and re-export them from a single place for the rest of the package.
+"""
+
+try:  # scanpy >= 1.13
+    from scanpy.plotting.legacy.palettes import default_20, default_28, default_102
+except ImportError:  # scanpy < 1.13
+    from scanpy.plotting.palettes import default_20, default_28, default_102
+
+__all__ = ["default_20", "default_28", "default_102"]

src/spatialdata_plot/pl/utils.py

@@ -31,7 +31,6 @@
 from pandas.api.types import CategoricalDtype, is_numeric_dtype
 from pandas.core.arrays.categorical import Categorical
 from scanpy import settings
-from scanpy.plotting import palettes
 from scanpy.plotting._tools.scatterplots import _add_categorical_legend
 from spatialdata import (
     SpatialData,
@@ -57,6 +56,7 @@
 from xarray import DataArray, DataTree
 
 from spatialdata_plot._logging import logger
+from spatialdata_plot.pl._scanpy_palettes import default_102
 from spatialdata_plot.pl.render_params import (
     Color,
     ColorbarSpec,
@@ -451,7 +451,7 @@ def _stack_categorical_legend(
 # A per-entry legend past this many categories is unreadable, and scanpy builds it in O(categories^2)
 # (one autoscaling artist each), dominating the render — so skip it with a warning. Tied to scanpy's
 # default_102 palette, beyond which its *default* colors also stop being distinguishable (uniform grey).
-_MAX_LEGEND_CATEGORIES = len(palettes.default_102)
+_MAX_LEGEND_CATEGORIES = len(default_102)
 
 
 def _first_color_per_category(source: pd.Categorical, color_vector: Any) -> dict[Any, Any]: