add lifetime attr as item

src/py_eddy_tracker/observations/observation.py

@@ -288,6 +288,8 @@ def __getitem__(self, attr: str):
             return self.obs[attr]
         elif attr in VAR_DESCR_inv:
             return self.obs[VAR_DESCR_inv[attr]]
+        elif attr in ("lifetime", "age"):
+            return getattr(self, attr)
         raise KeyError("%s unknown" % attr)
 
     def __getattr__(self, attr):
@@ -1104,12 +1106,7 @@ def cost_function(records_in, records_out, distance):
 
     def shifted_ellipsoid_degrees_mask(self, other, minor=1.5, major=1.5):
         return shifted_ellipsoid_degrees_mask2(
-            self.lon,
-            self.lat,
-            other.lon,
-            other.lat,
-            minor,
-            major,
+            self.lon, self.lat, other.lon, other.lat, minor, major,
         )
 
     def fixed_ellipsoid_mask(

tests/test_track.py

@@ -45,3 +45,6 @@ def test_area_tracking_parameter():
         c.to_netcdf(h)
         c_reloaded = Correspondances.from_netcdf(h)
         assert class_kw == c_reloaded.class_kw
+
+    # test access to the lifetime (item)
+    eddies_tracked["lifetime"]