Observation attrs

modelskill/obs.py

@@ -8,7 +8,7 @@
 """
 from __future__ import annotations
 
-from typing import Literal, Optional
+from typing import Literal, Optional, Any, Union
 import warnings
 import pandas as pd
 import xarray as xr
@@ -21,6 +21,9 @@
     _parse_track_input,
 )
 
+# NetCDF attributes can only be str, int, float https://unidata.github.io/netcdf4-python/#attributes-in-a-netcdf-file
+Serializable = Union[str, int, float]
+
 
 def observation(
     data: DataInputType,
@@ -104,6 +107,15 @@ def __init__(
         super().__init__(data=data)
         self.data.attrs["weight"] = weight
 
+    @property
+    def attrs(self) -> dict[str, Any]:
+        """Attributes of the observation"""
+        return self.data.attrs
+
+    @attrs.setter
+    def attrs(self, value: dict[str, Serializable]) -> None:
+        self.data.attrs = value
+
     @property
     def weight(self) -> float:
         """Weighting factor for skill scores"""

tests/observation/test_point_obs.py

@@ -152,12 +152,22 @@ def test_attrs(klagshamn_filename):
     o1 = ms.PointObservation(
         klagshamn_filename, item=0, attrs={"a1": "v1"}, name="Klagshamn"
     )
-    assert o1.data.attrs["a1"] == "v1"
+    assert o1.attrs["a1"] == "v1"
+
+    o1.attrs["a2"] = "v2"
+    assert o1.attrs["a2"] == "v2"
 
     o2 = ms.PointObservation(
         klagshamn_filename, item=0, attrs={"version": 42}, name="Klagshamn"
     )
-    assert o2.data.attrs["version"] == 42
+    assert o2.attrs["version"] == 42
+
+    o2.attrs["version"] = 43
+    assert o2.attrs["version"] == 43
+
+    # remove all attributes and add a new one
+    o2.attrs = {"version": 44}
+    assert o2.attrs["version"] == 44
 
 
 def test_attrs_non_serializable(klagshamn_filename):