load_tile_map: Register the rio accessor by importing rioxarray so the returned raster has CRS

Author: seisman

pygmt/datasets/tile_map.py

@@ -16,6 +16,13 @@
     TileProvider = None
     _HAS_CONTEXTILY = False
 
+try:
+    import rioxarray  # rioxarray is needed to register the rio accessor  # noqa: F401
+
+    _HAS_RIOXARRAY = True
+except ImportError:
+    _HAS_RIOXARRAY = False
+
 import numpy as np
 import xarray as xr
 
@@ -117,6 +124,11 @@ def load_tile_map(
       * y            (y) float64 ... -7.081e-10 -7.858e+04 ... -1.996e+07 -2.004e+07
       * x            (x) float64 ... -2.004e+07 -1.996e+07 ... 1.996e+07 2.004e+07
         spatial_ref  int64 ... 0
+    >>> # CRS is set only if rioxarray is available
+    >>> import importlib
+    >>> if importlib.util.find_spec("rioxarray"):
+    ...     raster.rio.crs
+    CRS.from_epsg(3857)
     """
     if not _HAS_CONTEXTILY:
         raise ImportError(