fastapi

Question

我是 fastapi 的新手，到目前为止它真的很棒，但我很难找到一种干净的方法将我的应用程序配置导入到另一个模块中。

编辑：我需要能够在运行单元测试

时更改配置

这是我的目录树：

/app
| __init__.py
| /router
| | __init__.py
| | my_router.py
| /test
| | test_api.py
| config.py
| main.py

这是我的 main.py 文件：

from functools import lru_cache

from fastapi import FastAPI

from .router import my_router
from . import config

app = FastAPI()

app.include_router(
    my_router.router,
    prefix="/r",
    tags=["my-router"],
)


@lru_cache()
def get_setting():
    return config.Settings(admin_email="admin@domain.com")


@app.get('/')
def hello():
    return 'Hello world'

这里是 router.py:

from fastapi import APIRouter

from ..main import get_setting

router = APIRouter()

@router.get('/test')
def get_param_list(user_id: int):
    config = get_setting()
    return 'Import Ok'

这是配置文件

from pydantic import BaseSettings


class Settings(BaseSettings):
    param_folder: str = "param"
    result_folder: str = "output"

    class Config:
        env_prefix = "APP_"

然后运行 uvicorn app.main:app --reload 我得到了：ERROR: Error loading ASGI app. Could not import module "app.main". 我猜是因为一种循环导入。但是我不知道如何将我的配置传递给我的路由器？

感谢您的帮助:)

Answer 1

直接在config.py里面设置lru缓存怎么样？

from functools import lru_cache
from pydantic import BaseSettings


class Settings(BaseSettings):
    admin_email: str = "admin@example.com"
    param_folder: str = "param"
    result_folder: str = "output"

    class Config:
        env_prefix = "APP_"

@lru_cache()
def get_setting():
    return Settings()

和my_router.py

from fastapi import APIRouter, Depends

from ..config import Settings, get_setting

router = APIRouter()

@router.get('/test')
def get_param_list(config: Settings = Depends(get_setting)):
    return config

和test.py

from fastapi.testclient import TestClient

from . import config, main

client = TestClient(main.app)


def get_settings_override():
    return config.Settings(admin_email="testing_admin@example.com")


main.app.dependency_overrides[config.get_settings] = get_settings_override

def test_app():
    response = client.get("/r/test")
    data = response.json()
    assert data == config.Settings(admin_email="testing_admin@example.com")

Answer 2

我使用 FastAPI 依赖系统让它工作，并且按照@Kassym Dorsel 的建议，通过将 lru_cache 移动到 config.py。

唯一的缺点是我必须在每个需要设置的函数调用中添加相当“繁重”的 setting: config.Setting = Depends(config.get_setting)。

我是这样做的：

config.py 文件:

from pydantic import BaseSettings


class Settings(BaseSettings):
    param_folder: str = "param"
    result_folder: str = "output"

    class Config:
        env_prefix = "APP_"

@lru_cache()
def get_setting():
    return config.Settings(admin_email="admin@domain.com")

main.py 文件:

from functools import lru_cache

from fastapi import FastAPI

from .router import my_router

app = FastAPI()

app.include_router(
    my_router.router,
    prefix="/r",
    tags=["my-router"],
)

@app.get('/')
def hello():
    return 'Hello world'

router.py 文件:

from fastapi import APIRouter, Depends

from .. import config

router = APIRouter()

@router.get('/test')
def get_param_list(user_id: int, setting: config.Setting = Depends(config.get_setting)):
    return setting

这样我就可以在 test_api.py 中使用 dependency_overrides 来更改测试配置：

from fastapi.testclient import TestClient

from .. import config, server

client = TestClient(server.app)

TEST_PARAM_FOLDER = 'server/test/param'
TEST_RESULT_FOLDER = 'server/test/result'

def get_setting_override():
    return config.Setting(param_folder=TEST_PARAM_FOLDER, result_folder=TEST_RESULT_FOLDER)


server.app.dependency_overrides[config.get_setting] = get_setting_override

def test_1():
    ...

Answer 3

The only draw back with this is that I must add the setting: config.Setting = Depends(config.get_setting), which is quite "heavy", to every function call that needs the setting.

您可以使用 fastapi_utils 包中的 Class Based Views：

from fastapi import APIRouter, Depends
from fastapi_utils.cbv import cbv
from starlette import requests
from logging import Logger
from .. import config

router = APIRouter()

@cbv(router)
class MyQueryCBV:
    settings: config.Setting = Depends(config.get_setting)  # you can introduce settings dependency here

    def __init__(self, r: requests.Request):  # called for each query
        self.logger: Logger = self.settings.logger
        self.logger.warning(str(r.headers))

    @router.get('/test')
    def get_param_list(self, user_id: int)
        self.logger.warning(f"get_param_list: {user_id}")
        return self.settings

    @router.get("/test2")
    def get_param_list2(self):
        self.logger.warning(f"get_param_list2")
        return self.settings

fastapi - 从 main.py 导入配置

fastapi - import config from main.py

python

python-3.x

python-import