Pydantic v2无法找到SettingsSourceCallable的问题咨询

正在查阅Pydantic 2.4迁移指南，无法找到SettingsSourceCallable的正确导入路径，现有代码因导入语句报错：

from pydantic.env_settings import SettingsSourceCallable

报错信息：

ImportError: cannot import name 'SettingsSourceCallable' from 'pydantic.env_settings' (/usr/local/lib/python3.9/site-packages/pydantic/env_settings.py)

fastapi~=0.103.2
pydantic~=2.4.2 
uvicorn[standard]~=0.23.2
aiohttp~=3.8.3
PyJWT~=1.7.1
requests~=2.27.1
starlette~=0.27.0
starlette-context~=0.3.6
jose
python-jose-cryptodome
pytest~=7.1.2
pytest-asyncio~=0.19.0
pytest-cov~=3.0.0
aioresponses~=0.7.3

• 安装独立的pydantic-settings包：Pydantic 2.x版本中，BaseSettings及相关类型（包括SettingsSourceCallable）已从核心pydantic包迁移至该独立包，执行安装命令：

  pip install pydantic-settings~=2.4.0
  

• 修改导入语句为：

  from pydantic_settings import SettingsSourceCallable
  

• 更新requirements.txt，添加pydantic-settings~=2.4.0条目，保证部署环境同步安装该依赖。

内容的提问来源于stack exchange，提问作者GustaMan9000