def get_lists():
c = DatabaseConnection()
listid = request.args.get("listid", 0)
if listid:
l = c.get_list(listid)
if not l:
return {"err": "list does not exist"}, 409
return {"list": l}, 200
username = request.args.get("username", "")
if not username:
return {"lists": c.get_lists()}, 200
user = c.get_user(username=username)
if not user:
return {"err": "user does not exist"}, 409
return {"lists": c.get_lists(userid=user["id"])}, 200
