refactor!: Drop pillow as a required dependency

CHANGELOG.rst

@@ -1,3 +1,9 @@
+Version 0.17.0 ()
+---------------------------
+
+NOTE: This drops pillow as a required dependency.
+
+
 Version 0.16.3 (2024-07-04)
 ---------------------------
 

datashader/tests/test_tiles.py

@@ -1,4 +1,7 @@
 from __future__ import annotations
+
+import pytest
+
 import datashader as ds
 import datashader.transfer_functions as tf
 
@@ -43,7 +46,7 @@ def mock_shader_func(agg, span=None):
 
 
 def mock_post_render_func(img, **kwargs):
-    from PIL import ImageDraw
+    ImageDraw = pytest.importorskip("PIL.ImageDraw")
 
     (x, y) = (5, 5)
     info = "x={} / y={} / z={}, w={}, h={}".format(kwargs['x'],
@@ -59,6 +62,8 @@ def mock_post_render_func(img, **kwargs):
 
 # TODO: mark with slow_test
 def test_render_tiles():
+    pytest.importorskip("PIL")
+
     full_extent_of_data = (-500000, -500000,
                            500000, 500000)
     levels = list(range(2))

datashader/tests/test_transfer_functions.py

@@ -5,7 +5,6 @@
 import numpy as np
 import xarray as xr
 import dask.array as da
-import PIL
 import pytest
 import datashader.transfer_functions as tf
 from datashader.tests.test_pandas import assert_eq_ndarray, assert_eq_xr, assert_image_close
@@ -1123,11 +1122,14 @@ def test_eq_hist(rng):
 
 
 def test_Image_to_pil():
+    PIL = pytest.importorskip('PIL')
     img = img1.to_pil()
     assert isinstance(img, PIL.Image.Image)
 
 
 def test_Image_to_bytesio():
+    pytest.importorskip('PIL')
+
     bytes = img1.to_bytesio()
     assert isinstance(bytes, BytesIO)
     assert bytes.tell() == 0

datashader/tiles.py

@@ -1,4 +1,5 @@
 from __future__ import annotations
+from importlib.util import find_spec
 from io import BytesIO
 
 import math
@@ -9,8 +10,6 @@
 
 import numpy as np
 
-from PIL.Image import fromarray
-
 __all__ = ['render_tiles', 'MercatorTileDefinition']
 
 
@@ -292,11 +291,15 @@ def __init__(self, tile_definition, output_location, tile_format='PNG',
         self.tile_format = tile_format
         self.post_render_func = post_render_func
 
+        if find_spec("PIL") is None:
+            raise ImportError('pillow is required to render tiles')
         # TODO: add all the formats supported by PIL
         if self.tile_format not in ('PNG', 'JPG'):
             raise ValueError('Invalid output format')
 
     def render(self, da, level):
+        from PIL.Image import fromarray
+
         xmin, xmax = self.tile_def.x_range
         ymin, ymax = self.tile_def.y_range
         extent = xmin, ymin, xmax, ymax

datashader/transfer_functions/__init__.py

@@ -11,7 +11,6 @@
 import toolz as tz
 import xarray as xr
 import dask.array as da
-from PIL.Image import fromarray
 
 from datashader.colors import rgb, Sets1to3
 from datashader.utils import nansum_missing, ngjit
@@ -30,6 +29,8 @@ class Image(xr.DataArray):
     border=1
 
     def to_pil(self, origin='lower'):
+        from PIL.Image import fromarray
+
         data = self.data
         if cupy:
             data = cupy.asnumpy(data)

pixi.toml

@@ -29,7 +29,6 @@ multipledispatch = "*"
 numpy = "*"
 pandas = "*"
 param = "*"
-pillow = "*"
 pip = "*"
 pyct = "*"
 requests = "*"
@@ -64,6 +63,7 @@ holoviews = "*"
 matplotlib-base = ">=3.3"
 networkx = "*"
 panel = ">1.1"
+pillow = "*"
 pyogrio =  "*"
 python-graphviz = "*"
 python-snappy = "*"
@@ -96,6 +96,7 @@ geodatasets = "*"
 geopandas-base = "*"
 netcdf4 = "*"
 pyarrow = "*"
+pillow = "*"
 pyogrio =  "*"
 rasterio = "*"
 rioxarray = "*"

pyproject.toml

@@ -35,7 +35,6 @@ dependencies = [
     'numpy',
     'pandas',
     'param',
-    'pillow',
     'pyct',
     'requests',
     'scipy',