iter_datapoints for empty query results

Author: lukasbindreiter

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- `tilebox-datasets`: Allow `iter_datapoints()` to handle empty query results.
+
 ## [0.60.0] - 2026-08-25
 
 ### Changed

prek.toml

@@ -19,7 +19,7 @@ hooks = [
 
 [[repos]]
 repo = "https://github.com/charliermarsh/ruff-pre-commit"
-rev = "v0.16.2"
+rev = "v0.16.4"
 hooks = [
   {
     id = "ruff-check",

tilebox-datasets/tests/test_assets.py

@@ -595,6 +595,7 @@ def test_missing_referenced_context_is_rejected() -> None:
 def test_iter_datapoints_and_multi_datapoint_error() -> None:
     data = xr.Dataset({"value": ("time", [1, 2, 3])})
     assert [datapoint.value.item() for datapoint in iter_datapoints(data)] == [1, 2, 3]
+    assert list(iter_datapoints(xr.Dataset())) == []
     with pytest.raises(ValueError, match=r"(?s)received 3.*dimension 'time'"):
         AssetCollection.from_datapoint(data)
     with pytest.raises(ValueError, match=r"'sample'.*not present"):

tilebox-datasets/tilebox/datasets/datapoints.py

@@ -7,6 +7,9 @@
 
 def iter_datapoints(data: xr.Dataset, *, dimension: str = "time") -> Iterator[xr.Dataset]:
     """Yield scalar datapoints from an xarray query result."""
+    if not data.variables:
+        # Empty query results produce an empty iterator.
+        return
     if dimension not in data.sizes:
         raise ValueError(f"datapoint dimension {dimension!r} is not present in the dataset")
     for index in range(data.sizes[dimension]):