Improved achievement endpoint #268_achievements

kdb-bot/src/bot_data/model/achievement.py

@@ -21,6 +21,10 @@ class Achievement(TableABC):
         self._id = id
         self._name = name
         self._attribute = attribute
+
+        if operator not in ["==", "!=", "<=", ">=", "<", ">"]:
+            raise ValueError("operator must be ==,!=,<=,>=,< or >")
+
         self._operator = operator
         self._value = value
         self._server = server