Cleanup reader to keep attr over scale and mask to preserve the renam…

…e of valid range with space. Added test to test this

satpy/readers/hy2_scat_l2b_h5.py

@@ -107,11 +107,13 @@ def get_dataset(self, key, info):
         else:
             dim_map = {curr_dim: new_dim for curr_dim, new_dim in zip(data.dims, dims)}
             data = data.rename(dim_map)
-            data = self._mask_data(key['name'], data)
-            data = self._scale_data(key['name'], data)
+            data = self._mask_data(data)
+            data = self._scale_data(data)
 
             if key['name'] in 'wvc_lon':
+                _attrs = data.attrs
                 data = xr.where(data > 180, data - 360., data)
+                data.attrs.update(_attrs)
         data.attrs.update(info)
         data.attrs.update(self.get_metadata())
         data.attrs.update(self.get_variable_metadata())
@@ -120,13 +122,14 @@ def get_dataset(self, key, info):
 
         return data
 
-    def _scale_data(self, key_name, data):
-        return data * self[key_name].attrs['scale_factor'] + self[key_name].attrs['add_offset']
+    def _scale_data(self, data):
+        return data * data.attrs['scale_factor'] + data.attrs['add_offset']
 
-    def _mask_data(self, key_name, data):
-        data = xr.where(data == self[key_name].attrs['fill_value'], np.nan, data)
-
-        valid_range = self[key_name].attrs['valid_range']
+    def _mask_data(self, data):
+        _attrs = data.attrs
+        valid_range = data.attrs['valid_range']
+        data = xr.where(data == data.attrs['fill_value'], np.nan, data)
         data = xr.where(data < valid_range[0], np.nan, data)
         data = xr.where(data > valid_range[1], np.nan, data)
+        data.attrs.update(_attrs)
         return data

satpy/tests/reader_tests/test_hy2_scat_l2b_h5.py

@@ -40,6 +40,13 @@
 class FakeHDF5FileHandler2(FakeHDF5FileHandler):
     """Swap-in HDF5 File Handler."""
 
+    def __getitem__(self, key):
+        """Return copy of dataarray to prevent manipulating attributes in the original."""
+        val = self.file_content[key]
+        if isinstance(val, xr.core.dataarray.DataArray):
+            val = val.copy()
+        return val
+
     def _get_geo_data(self, num_rows, num_cols):
         geo = {
             'wvc_lon':
@@ -498,3 +505,20 @@ def test_reading_attrs_nsoas(self):
         with self.assertRaises(KeyError):
             self.assertEqual(res['wvc_lon'].attrs['L2B_Number_WVC_cells'], 10)
         self.assertEqual(res['wvc_lon'].attrs['L2B_Expected_WVC_Cells'], 10)
+
+    def test_properties(self):
+        """Test platform_name."""
+        from datetime import datetime
+
+        from satpy.readers import load_reader
+        filenames = [
+            'W_XX-EUMETSAT-Darmstadt,SURFACE+SATELLITE,HY2B+SM_C_EUMP_20200326------_07077_o_250_l2b.h5', ]
+
+        reader = load_reader(self.reader_configs)
+        files = reader.select_files_from_pathnames(filenames)
+        reader.create_filehandlers(files)
+        # Make sure we have some files
+        res = reader.load(['wvc_lon'])
+        self.assertEqual(res['wvc_lon'].platform_name, 'HY-2B')
+        self.assertEqual(res['wvc_lon'].start_time, datetime(2020, 3, 26, 1, 11, 7))
+        self.assertEqual(res['wvc_lon'].end_time, datetime(2020, 3, 26, 2, 55, 40))