Update app.py

app.py

@@ -1,3 +1,6 @@
+from fastapi import FastAPI, HTTPException
+from typing import Optional, List 
+from pydantic import BaseModel
 
 app = FastAPI()
 # 1 Define blueprint 
@@ -17,7 +20,7 @@ def create_customer(customer: Customer):
     return customer
 
 #Read
-@app.get("/Customer",response_model=list[Customer])
+@app.get("/Customer",response_model=List[Customer])
 def get_customer():
     return customer_list