Refactor dependencies to make more optional

pyproject.toml

@@ -22,35 +22,43 @@ requires-python = ">=3.10"
 # minimal dependencies start
 dependencies = [
   "antimeridian",
-  "cartopy",
   "dask[dataframe]",
-  "datashader",
-  "geoviews",
-  "holoviews",
-  "matplotlib",
-  "matplotlib-inline",
   "netcdf4",
   "numba",
   "numpy",
   "pandas",
-  "pyarrow",
-  "requests",
   "scikit-learn",
   "scipy",
   "shapely",
-  "spatialpandas",
-  "geopandas",
   "xarray",
-  "hvplot",
-  "healpix",
+  "hvplot",  # TODO: move to viz after PR #1541 gets merged.
   "polars",
-  "pyproj"
 ]
 # minimal dependencies end
 
 [project.optional-dependencies]
-complete = ["uxarray[dev]"]
-dev = ['pathlib', 'pre_commit', 'pytest', 'pytest-cov', 'ruff', 'asv']
+all = ["uxarray[dev,geo,viz]"]
+complete = ["uxarray[dev,geo,viz]"]  # alias to "all"
+dev = [
+    'asv',
+    'pooch',
+    'pre_commit',
+    'pytest',
+    'pytest-cov',
+    'ruff',
+]
+geo = [
+    "geopandas",
+    "healpix",
+    "pyproj",
+    "spatialpandas",
+]
+viz = [
+    "cartopy",
+    "geoviews",
+    "holoviews",
+    "matplotlib",
+]
 
 [project.urls]
 Documentation = "https://uxarray.readthedocs.io/"

test/io/test_structured.py

@@ -2,6 +2,9 @@
 import xarray as xr
 import pytest
 
+# import pooch  # not necessary to actually import, but tests would likely fail if this fails.
+# (commented here for future reference, since pooch is included in uxarray[dev]
+#    dependencies, but not imported explicitly anywhere in uxarray.)
 
 @pytest.mark.parametrize("ds_name", ["air_temperature", "ersstv5"])
 def test_read_structured_grid_from_ds(ds_name):

uxarray/core/dataarray.py

@@ -5,10 +5,8 @@
 from typing import TYPE_CHECKING, Any, Hashable, Literal, Mapping, Optional
 from warnings import warn
 
-import cartopy.crs as ccrs
 import numpy as np
 import xarray as xr
-from cartopy.mpl.geoaxes import GeoAxes
 from xarray.core import dtypes
 from xarray.core.options import OPTIONS
 from xarray.core.utils import UncachedAccessor
@@ -37,6 +35,9 @@
 from uxarray.subset import DataArraySubsetAccessor
 
 if TYPE_CHECKING:
+    import cartopy.crs as ccrs
+    from cartopy.mpl.geoaxes import GeoAxes
+
     from uxarray.core.dataset import UxDataset
 
 
@@ -462,6 +463,8 @@ def to_raster(
         >>> ax.imshow(raster, origin="lower", extent=ax.get_xlim() + ax.get_ylim())
 
         """
+        from cartopy.mpl.geoaxes import GeoAxes
+
         from uxarray.constants import INT_DTYPE
         from uxarray.plot.matplotlib import (
             _ensure_dimensions,

uxarray/cross_sections/sample.py

@@ -1,6 +1,5 @@
 import numpy as np
 from numba import njit, prange
-from pyproj import Geod
 
 
 @njit(parallel=True)
@@ -17,6 +16,8 @@ def _fill_numba(flat_orig, face_idx, n_face, n_steps):
 def sample_geodesic(
     start: tuple[float, float], end: tuple[float, float], steps: int
 ) -> tuple[np.ndarray, np.ndarray]:
+    from pyproj import Geod
+
     lon0, lat0 = start
     lon1, lat1 = end
 

uxarray/grid/geometry.py

@@ -397,8 +397,6 @@ def _build_corrected_polygon_shells(polygon_shells):
     _corrected_shells_to_original_faces : np.ndarray
         Original indices used to map the corrected polygon shells to their entries in face nodes
     """
-
-    # import optional dependencies
     import antimeridian
     from shapely import Polygon
 

uxarray/grid/grid.py

@@ -1,10 +1,11 @@
+from __future__ import annotations
+
 import copy
 import os
 from html import escape
-from typing import Optional, Sequence
+from typing import TYPE_CHECKING, Optional, Sequence
 from warnings import warn
 
-import cartopy.crs as ccrs
 import numpy as np
 import xarray as xr
 from xarray.core.options import OPTIONS
@@ -99,6 +100,9 @@
 from uxarray.plot.accessor import GridPlotAccessor
 from uxarray.subset import GridSubsetAccessor
 
+if TYPE_CHECKING:
+    import cartopy.crs as ccrs
+
 
 class Grid:
     """Represents a two-dimensional unstructured grid encoded following the

uxarray/io/_healpix.py

@@ -1,6 +1,5 @@
 from typing import Any
 
-import healpix as hp
 import numpy as np
 import polars as pl
 import xarray as xr
@@ -68,6 +67,8 @@ def pix2corner_ang(
     ----
     This will be updated when https://github.com/ntessore/healpix/issues/66 is implemented.
     """
+    import healpix as hp
+
     if nest:
         fu = hp._chp.nest2ang_uv
     else:
@@ -102,6 +103,8 @@ def _pixels_to_ugrid(zoom, nest):
         A dataset containing pixel longitude and latitude coordinates along with related attributes.
 
     """
+    import healpix as hp
+
     ds = xr.Dataset()
 
     nside = hp.order2nside(zoom)

uxarray/plot/utils.py

@@ -1,6 +1,3 @@
-import holoviews as hv
-
-
 class HoloviewsBackend:
     """Utility class to compare and set a HoloViews plotting backend for
     visualization."""
@@ -16,6 +13,7 @@ def assign(self, backend: str):
         backend : str
             Plotting backend to use, one of 'matplotlib', 'bokeh'
         """
+        import holoviews as hv
 
         if self.matplotlib_backend is None:
             import matplotlib as mpl

uxarray/remap/weights.py

@@ -4,13 +4,16 @@
 from dataclasses import dataclass
 from os import PathLike
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import numpy as np
 import xarray as xr
-from scipy import sparse
 
 from uxarray.core.utils import _open_dataset_with_fallback
 
+if TYPE_CHECKING:
+    from scipy import sparse
+
 # LRU-bounded cache for loaded remap operators.
 _WEIGHTS_CACHE_MAXSIZE = 32
 _WEIGHTS_CACHE: "OrderedDict[tuple[str, int, int], RemapWeights]" = OrderedDict()
@@ -83,6 +86,8 @@ class RemapWeights:
     @classmethod
     def from_file(cls, filename_or_obj: str | PathLike[str] | xr.Dataset):
         """Load a standard sparse remap-weight file into memory once."""
+        from scipy import sparse
+
         if isinstance(filename_or_obj, xr.Dataset):
             ds = filename_or_obj
             close_ds = False