got both classes working

fleet.py

@@ -28,13 +28,7 @@ addVehicle = Fleet("hovercraft", 50, "ground/water", 0)
 vehicle1.displayAllFleetMembers()
   
   
-class GroundVehicle(ABC, Vehicle):
 
-    
-    @abstractmethod
-    def __init__(self, volume):
-        # default value set to true. Many ground vehicles will have trailers or train cars. Modified as needed
-        self.isModular = True
         
 class Vehicle(ABC):
     '''Defines the properties of vehicles'''
@@ -49,3 +43,11 @@ class Vehicle(ABC):
         self.weightType = "kg"
         self.weight = 0
         
+class GroundVehicle(Vehicle):
+
+    
+    @abstractmethod
+    def __init__(self, volume):
+        # default value set to true. Many ground vehicles will have trailers or train cars. Modified as needed
+        self.isModular = True
+