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

@@ -853,12 +853,9 @@ class Dataset:
             )
 
     def __del__(self):
-        # TODO: refactor following try/except statement
-        try:
+        if self.inputFhandle:
             if not self.inputFhandle.closed:
                 self.inputFhandle.close()
-        except:
-            pass
 
     def __repr__(self):
         # TODO: this could be more meaningful