move detail's comment to code

sohstationviewer/view/db_config/value_color_helper/edit_value_color_dialog/multi_color_dot_dialog.py

@@ -253,8 +253,7 @@ class MultiColorDotDialog(EditValueColorDialog):
             + If the last row is empty string, that value will be eliminated
                 from condition.
             + If value not greater than previous row and less than latter row,
-                give error message. -20 and 20 are given to previous or latter
-                row if not exist b/c they are out of range of bound [-10, 10]
+                give error message.
         Call set_value_row_id_dict to keep track of value by row_id.
 
         :param row_id: id of the row being checked.
@@ -272,9 +271,12 @@ class MultiColorDotDialog(EditValueColorDialog):
 
         self.changed_row_id = None
 
+        # -20 is assigned to higher bound of the row before the first row
+        # to always satisfy validating this row's higher bound value for value
+        # range is [-10,10]
         prev_higher_bound = (
-            float(self.higher_bound_lnedits[row_id - 1].text())
-            if row_id > 0 else -20)
+            -20 if row_id == 0
+            else float(self.higher_bound_lnedits[row_id - 1].text()))
 
         if self.higher_bound_lnedits[row_id].text().strip() == '':
             self.handle_clear_higher_bound(row_id)
@@ -282,13 +284,12 @@ class MultiColorDotDialog(EditValueColorDialog):
             self.save_colors_btn_clicked = False
             return
 
-        if row_id >= len(self.row_id_value_dict) - 1:
-            # When the current higher_bound_lnedits is on the last row
-            # set the limit 20 to be the next_higher_bound
-            next_higher_bound = 20
-        else:
-            next_higher_bound = float(
-                self.higher_bound_lnedits[row_id + 1].text())
+        # 20 is assigned to higher bound of the row after the last edited row
+        # to always satisfy validating this row's higher bound value for value
+        # range is [-10,10]
+        next_higher_bound = (
+            20 if row_id == len(self.row_id_value_dict) - 1
+            else float(self.higher_bound_lnedits[row_id + 1].text()))
 
         curr_higher_bound = float(self.higher_bound_lnedits[row_id].text())
         if (curr_higher_bound <= prev_higher_bound