added variables_with_nans in dataset metadata

ecml_tools/create/loaders.py

@@ -190,9 +190,7 @@ def initialise(self, check_name=True):
         variables = self.minimal_input.variables
         self.print(f"Found {len(variables)} variables : {','.join(variables)}.")
 
-        variables_with_nans = self.minimal_input.variables_with_nans
-        if variables_with_nans:
-            print(f"  Found nans for {' '.join(variables_with_nans)}")
+        variables_with_nans = self.config.get("has_nans", [])
 
         ensembles = self.minimal_input.ensembles
         self.print(f"Found {len(ensembles)} ensembles : {','.join([str(_) for _ in ensembles])}.")
@@ -236,6 +234,7 @@ def initialise(self, check_name=True):
 
         metadata["ensemble_dimension"] = len(ensembles)
         metadata["variables"] = variables
+        metadata["variables_with_nans"] = variables_with_nans
         metadata["resolution"] = resolution
 
         metadata["licence"] = self.main_config["licence"]