minor edits

ess/TraceWin.py

@@ -400,7 +400,7 @@ class plt:
             ret = {}
 
             # if want to EXCLUDE lost particles (default):
-            if self.flag_remove_loss == True:
+            if self.flag_remove_loss:
                 lost_mask = self._data[i]["l"] == 0
                 for para in self._data[i]:
                     if isinstance(self._data[i][para], numpy.ndarray):
@@ -416,7 +416,7 @@ class plt:
             return ret
 
         else:
-            print("No data to plot at element", key)
+            print(f"No data available for element {key}")
 
     def calc_s(self):
         """