Review this session cache helper

import pickle
import redis

r = redis.Redis(host="redis", port=6379, db=0)

def cache_session(session_id: str, data: dict):
    r.set(f"session:{session_id}", pickle.dumps(data))

def get_session(session_id: str) -> dict:
    raw = r.get(f"session:{session_id}")
    if raw is None:
        return {}
    return pickle.loads(raw)

def delete_session(session_id: str):
    r.delete(f"session:{session_id}")