Also directly accessing numpy array in Particle.__getattr__

Although this does not appear to result in a speed-up

Author: erikvansebille

parcels/particle.py

@@ -115,7 +115,7 @@ def __init__(self, data: xr.Dataset, index: int):
         self._index = index
 
     def __getattr__(self, name):
-        return self._data[name].values[self._index]
+        return self._data[name].data[self._index]
 
     def __setattr__(self, name, value):
         if name in ["_data", "_index"]: