scores = [("张三", 85), ("李四", 92), ("王五", 78), ("赵六", 95)]
# 使用字典推导式筛选分数大于等于90的条目
new_dict = {name: score for name, score in scores if score >= 90}
new_dict["孙七"] = 88
print(new_dict.get("李四", 0) + new_dict.get("孙七", 0))