code refactor

related to #8 (closed):

• I kept changes per commit small, so the number of commits got kind of numerous...

src/icartt/dataset.py

@@ -534,8 +534,8 @@ class Dataset:
         # here that the independent variable should monotonically increase even when
         # crossing over to a second day.
 
-        def extractVardesc(dmp):
-            shortname = dmp[0]
+        def extractVardesc(dmp): # TODO: could be a 'utils' function or one line,
+            shortname = dmp[0]   # shortname, units, standardname, longname, *_ = dmp + [None] * 3
             units = dmp[1]
             standardname = dmp[2] if len(dmp) > 2 else None
             longname = dmp[3] if len(dmp) > 3 else None