[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

recipes/mursst/recipe.py

@@ -67,18 +67,14 @@ class Preprocess(beam.PTransform):
 
     @staticmethod
     def _preproc(item: Indexed[T]) -> Indexed[T]:
-        SELECTED_VARS = {
-            'analysed_sst',
-            'analysis_error',
-            'mask',
-            'sea_ice_fraction'
-        }
+        SELECTED_VARS = {'analysed_sst', 'analysis_error', 'mask', 'sea_ice_fraction'}
         index, ds = item
         return index, ds.drop([k for k in ds.data_vars.keys() if k not in SELECTED_VARS])
 
     def expand(self, pcoll: beam.PCollection) -> beam.PCollection:
         return pcoll | beam.Map(self._preproc)
 
+
 # use HTTP_REL if S3 access is not possible. S3_REL is faster.
 selected_rel = S3_REL
 pattern = pattern_from_file_sequence(