Simplify tariff_key assigning function

Author: alexhyunminlee

utils/types.py

@@ -5,12 +5,16 @@ class SB_scenario:
     analysis_type: Literal["default", "seasonal", "class_specific_seasonal"]
     analysis_year: int
 
-    def __init__(self, analysis_type: Literal["default", "seasonal", "class_specific_seasonal"], analysis_year: int):
+    def __init__(
+        self,
+        analysis_type: Literal["default", "seasonal", "class_specific_seasonal"],
+        analysis_year: int,
+    ):
         self.analysis_type = analysis_type
         self.analysis_year = analysis_year
-    
+
     def __str__(self):
         return f"{self.analysis_type}_{self.analysis_year}"
 
-    
+
 electric_utility = Literal["Coned", "National Grid", "NYSEG"]