如何在算术表达式的结果上放置SQLAlchemy标签？

from sqlalchemy import create_engine, Column, Integer, String, select, func
from sqlalchemy.orm import declarative_base, relationship
from sqlalchemy.sql import label

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    age = Column(Integer)

engine = create_engine("sqlite:///sqlalchemy_example.db")
Base.metadata.create_all(engine)

# 插入一些示例数据
users = [
    User(name="Alice", age=30),
    User(name="Bob", age=25),
    User(name="Charlie", age=35)
]

with engine.begin() as conn:
    conn.add_all(users)

# 使用标签为算术表达式的结果添加标签
with engine.connect() as conn:
    result = conn.execute(
        select(
            label("average_age", func.avg(User.age))
        )
    )
    for row in result:
        print(f"Average age: {row.average_age}")