Use smaller file

Author: maxrjones

README.md

@@ -28,16 +28,20 @@ pip install obspec-utils
 ```python
 import xarray as xr
 from obstore.store import S3Store
-from obspec_utils.readers import BlockStoreReader
+from obspec_utils.glob import glob
+from obspec_utils.readers import EagerStoreReader
 
 store = S3Store(
-    bucket="nsf-ncar-era5",
+    bucket="its-live-data",
     aws_region="us-west-2",
     skip_signature=True,
 )
 
-with BlockStoreReader(store, "e5.oper.an.pl/202501/e5.oper.an.pl.128_060_pv.ll025sc.2025010100_2025010123.nc") as reader:
-    ds = xr.open_dataset(reader, engine="h5netcdf")
+# Find NetCDF files matching a pattern
+files = glob(store, "NSIDC/velocity_image_pair_sample/landsatOLI/v02/N20E080/*.nc")
+path = next(files)
+
+with EagerStoreReader(store, path) as reader, xr.open_dataset(reader, engine="h5netcdf") as ds:
     print(ds)
 ```
 

tests/test_xarray.py

@@ -59,34 +59,30 @@ def test_readme_example():
     """
     Test the example from the README frontpage.
 
-    Uses ERA5 data from the NSF-NCAR public S3 bucket.
+    Uses ITS_LIVE velocity data from a public S3 bucket.
     Verifies output matches fsspec.
     """
     import s3fs
     from obstore.store import S3Store
+    from obspec_utils.glob import glob
 
-    bucket = "nsf-ncar-era5"
-    path = (
-        "e5.oper.an.pl/202501/e5.oper.an.pl.128_060_pv.ll025sc.2025010100_2025010123.nc"
-    )
-
+    bucket = "its-live-data"
     store = S3Store(
         bucket=bucket,
         aws_region="us-west-2",
         skip_signature=True,
     )
+
+    # Find NetCDF files matching a pattern
+    files = glob(store, "NSIDC/velocity_image_pair_sample/landsatOLI/v02/N20E080/*.nc")
+    path = files[0]
+
     fs = s3fs.S3FileSystem(anon=True)
 
     with (
         fs.open(f"{bucket}/{path}") as f,
-        BlockStoreReader(store, path) as reader,
+        EagerStoreReader(store, path) as reader,
         xr.open_dataset(f, engine="h5netcdf") as ds_fsspec,
         xr.open_dataset(reader, engine="h5netcdf") as ds_obspec,
     ):
-        # Compare indexes
-        assert list(ds_fsspec.indexes) == list(ds_obspec.indexes)
-        # Load just one point to verify data access
-        var = list(ds_obspec.data_vars)[0]
-        subset_fsspec = ds_fsspec[var].isel({d: 0 for d in ds_fsspec[var].dims})
-        subset_obspec = ds_obspec[var].isel({d: 0 for d in ds_obspec[var].dims})
-        xr.testing.assert_equal(subset_fsspec, subset_obspec)
+        xr.testing.assert_allclose(ds_fsspec.load(), ds_obspec.load())