modified some Python files

item.py

@@ -1,4 +1,4 @@
-from .serializable import Serializable
+from serializable import Serializable
 
 class Item(Serializable):
     def __init__(self,name:str, description:str, stat_modifier:str, weight:float = 10.0):
@@ -9,7 +9,7 @@ class Item(Serializable):
         self.weight = weight
     
     def __str__(self):
-        return self.name + '(' + self.weight + ' kg)' + ': ' + self.description
+        return f"{self.name} ({self.weight} kg): {self.description}"
 
 class Equippable(Item):
     def __init__(self, name, description, stat_modifier, equipped:bool, weight = 10.0):