HTML representation from query raises IndexError for empty result

[DahnJ]

Thanks for this package, looks like a great API for vector-raster operations!

Description

HTML representation from query raises IndexError for empty results.

MRE

import geopandas as gpd
import xarray as xr
import xvec

from geodatasets import get_path

from shapely.geometry import Point

counties = gpd.read_file(get_path("geoda.natregimes"))

# From https://xvec.readthedocs.io/en/stable/intro.html
cube = xr.Dataset(
    data_vars=dict(
        population=(["county", "year"], counties[["PO60", "PO70", "PO80", "PO90"]]),
        unemployment=(["county", "year"], counties[["UE60", "UE70", "UE80", "UE90"]]),
        divorce=(["county", "year"], counties[["DV60", "DV70", "DV80", "DV90"]]),
        age=(["county", "year"], counties[["MA60", "MA70", "MA80", "MA90"]]),
    ),
    coords=dict(county=counties.geometry, year=[1960, 1970, 1980, 1990]),
).xvec.set_geom_indexes("county", crs=counties.crs)

# Has 1 result, HTML representation works fine
result = cube.xvec.query(
    "county", 
    [Point(-94.9, 48.7).buffer(0.1)],
    predicate="within"
)
result._repr_html_()

# This has 0 results, errors during HTML repr
result = cube.xvec.query(
    "county", 
    [Point(-94.9, 48.7).buffer(1)],
    predicate="within"
)
result._repr_html_()

Traceback

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
Cell In[16], line 1
----> 1 result._repr_html_()

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/dataset.py:2578, in Dataset._repr_html_(self)
   2576 if OPTIONS["display_style"] == "text":
   2577     return f"<pre>{escape(repr(self))}</pre>"
-> 2578 return formatting_html.dataset_repr(self)

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:344, in dataset_repr(ds)
    336 obj_type = f"xarray.{type(ds).__name__}"
    338 header_components = [f"<div class='xr-obj-type'>{escape(obj_type)}</div>"]
    340 sections = [
    341     dim_section(ds),
    342     coord_section(ds.coords),
    343     datavar_section(ds.data_vars),
--> 344     index_section(_get_indexes_dict(ds.xindexes)),
    345     attr_section(ds.attrs),
    346 ]
    348 return _obj_repr(ds, header_components, sections)

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:205, in _mapping_section(mapping, name, details_func, max_items_collapse, expand_option_name, enabled)
    198 expanded = _get_boolean_with_default(
    199     expand_option_name, n_items < max_items_collapse
    200 )
    201 collapsed = not expanded
    203 return collapsible_section(
    204     name,
--> 205     details=details_func(mapping),
    206     n_items=n_items,
    207     enabled=enabled,
    208     collapsed=collapsed,
    209 )

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:165, in summarize_indexes(indexes)
    164 def summarize_indexes(indexes) -> str:
--> 165     indexes_li = "".join(
    166         f"<li class='xr-var-item'>{summarize_index(v, i)}</li>"
    167         for v, i in indexes.items()
    168     )
    169     return f"<ul class='xr-var-list'>{indexes_li}</ul>"

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:166, in <genexpr>(.0)
    164 def summarize_indexes(indexes) -> str:
    165     indexes_li = "".join(
--> 166         f"<li class='xr-var-item'>{summarize_index(v, i)}</li>"
    167         for v, i in indexes.items()
    168     )
    169     return f"<ul class='xr-var-list'>{indexes_li}</ul>"

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:150, in summarize_index(coord_names, index)
    148 index_id = f"index-{uuid.uuid4()}"
    149 preview = escape(inline_index_repr(index))
--> 150 details = short_index_repr_html(index)
    152 data_icon = _icon("icon-database")
    154 return (
    155     f"<div class='xr-index-name'><div>{name}</div></div>"
    156     f"<div class='xr-index-preview'>{preview}</div>"
   (...)
    160     f"<div class='xr-index-data'>{details}</div>"
    161 )

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xarray/core/formatting_html.py:142, in short_index_repr_html(index)
    139 if hasattr(index, "_repr_html_"):
    140     return index._repr_html_()
--> 142 return f"<pre>{escape(repr(index))}</pre>"

File ~/miniconda3/envs/geo/lib/python3.12/site-packages/xvec/index.py:290, in GeometryIndex.__repr__(self)
    288     return f"GeometryIndex([{wkts[0]}], crs={srs})"
    289 joined = "\n ".join(wkts[1:])
--> 290 return f"GeometryIndex(\n[{wkts[0]}\n {joined}],\ncrs={srs})".replace(
    291     "\n", "\n" + " " * 4
    292 )

IndexError: list index out of range

Environment

• Python 3.12
• xvec: 0.3.0
• xarray: 2024.7.0

[martinfleis]

@DahnJ Thanks! Fixed!