Decode all timestamps to datetime

satpy/readers/satpy_cf_nc.py

@@ -334,23 +334,36 @@ class DatasetAttributeDecoder:
 
     def decode_attrs(self, dataset):
         """Decode dataset attributes."""
-        self._decode_dict_type_attrs(dataset)
+        self._decode_dict_type_attrs(dataset.attrs)
+        self._decode_timestamps(dataset.attrs)
 
-    def _decode_dict_type_attrs(self, data):
-        for key, val in data.attrs.items():
-            data.attrs[key] = self._str2dict(val)
+    def _decode_dict_type_attrs(self, attrs):
+        for key, val in attrs.items():
+            attrs[key] = self._str2dict(val)
 
     def _str2dict(self, val):
         """Convert string to dictionary."""
         if isinstance(val, str) and val.startswith("{"):
-            val = json.loads(val, object_hook=_datetime_parser)
+            val = json.loads(val, object_hook=_datetime_parser_json)
         return val
 
+    def _decode_timestamps(self, attrs):
+        for key, value in attrs.items():
+            timestamp = _str2datetime(value)
+            if timestamp:
+                attrs[key] = timestamp
 
-def _datetime_parser(json_dict):
+
+def _datetime_parser_json(json_dict):
     for key, value in json_dict.items():
-        try:
-            json_dict[key] = datetime.fromisoformat(value)
-        except (TypeError, ValueError):
-            pass
+        timestamp = _str2datetime(value)
+        if timestamp:
+            json_dict[key] = timestamp
     return json_dict
+
+
+def _str2datetime(string):
+    try:
+        return datetime.fromisoformat(string)
+    except (TypeError, ValueError):
+        return None

satpy/tests/reader_tests/test_satpy_cf_nc.py

@@ -111,7 +111,8 @@ def common_attrs(area):
         "end_time": datetime(2019, 4, 1, 12, 15),
         "platform_name": "tirosn",
         "orbit_number": 99999,
-        "area": area
+        "area": area,
+        "my_timestamp": datetime(2000, 1, 1)
     }
 
 
@@ -446,6 +447,14 @@ def test_decoding_of_dict_type_attributes(self, cf_scene, nc_filename):
             new_attrs = scn_["image0"].attrs[attr_name]
             assert new_attrs == orig_attrs
 
+    def test_decoding_of_timestamps(self, cf_scene, nc_filename):
+        """Test decoding of timestamps."""
+        cf_scene.save_datasets(writer="cf", filename=nc_filename)
+        scn = Scene(reader="satpy_cf_nc", filenames=[nc_filename])
+        scn.load(["image0"])
+        expected = cf_scene["image0"].attrs["my_timestamp"]
+        assert scn["image0"].attrs["my_timestamp"] == expected
+
     def test_write_and_read_from_two_files(self, nc_filename, nc_filename_i):
         """Save two datasets with different resolution and read the solar_zenith_angle again."""
         _create_test_netcdf(nc_filename, resolution=742)