Flask:如何避免缓慢、多次导入？

# app.py
from flask import Flask

def create_app():
    app = Flask(__name__)
    # 添加路由、配置等代码
    return app

# 其他模块中导入应用对象
from app import create_app
app = create_app()

# auth.py
from flask import Blueprint

auth_bp = Blueprint('auth', __name__)

@auth_bp.route('/login')
def login():
    # 登录逻辑
    pass

# app.py
from flask import Flask
from auth import auth_bp

def create_app():
    app = Flask(__name__)
    app.register_blueprint(auth_bp)
    # 添加其他蓝图、配置等代码
    return app

# 其他模块中导入应用对象
from app import create_app
app = create_app()

def some_function():
    from flask import Flask
    app = Flask(__name__)
    # 添加路由、配置等代码
    return app