def __init__(
        self, app: ASGIApp, context_name: str = "fastapi_middleware_astack"
    ) -> None:
        self.app = app
        self.context_name = context_name

    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
        async with AsyncExitStack() as stack:
            scope[self.context_name] = stack

from pytest import MonkeyPatch


@pytest.fixture(name="app", params=[pytest.param("tutorial001_py39")])
def get_app(request: pytest.FixtureRequest, monkeypatch: MonkeyPatch):
    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    mod = importlib.import_module(f"docs_src.settings.{request.param}")
    return mod.app


def test_settings(app):
    client = TestClient(app)
    response = client.get("/info")

from fastapi import FastAPI
from fastapi.openapi.utils import get_openapi

app = FastAPI()


@app.get("/items/")
async def read_items():
    return [{"name": "Foo"}]


def custom_openapi():
    if app.openapi_schema:
        return app.openapi_schema
    openapi_schema = get_openapi(
        title="Custom title",
        version="2.5.0",
        summary="This is a very custom OpenAPI schema",

from fastapi.testclient import TestClient

from docs_src.behind_a_proxy.tutorial001_py39 import app

client = TestClient(app, root_path="/api/v1")


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi():
    response = client.get("/openapi.json")
    assert response.status_code == 200

import pytest
from fastapi.testclient import TestClient

from docs_src.path_operation_configuration.tutorial006_py39 import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        ("/items/", 200, [{"name": "Foo", "price": 42}]),
        ("/users/", 200, [{"username": "johndoe"}]),
        ("/elements/", 200, [{"item_id": "Foo"}]),
    ],
)

from fastapi.testclient import TestClient

from docs_src.metadata.tutorial001_1_py39 import app

client = TestClient(app)


def test_items():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [{"name": "Katana"}]


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

      prefixes = ["/api/v1"]

  [http.routers]

    [http.routers.app-http]
      entryPoints = ["http"]
      service = "app"
      rule = "PathPrefix(`/api/v1`)"
      middlewares = ["api-stripprefix"]

  [http.services]

    [http.services.app]
      [http.services.app.loadBalancer]
        [[http.services.app.loadBalancer.servers]]
          url = "http://127.0.0.1:8000"
```

from pydantic import BaseModel, Field

app = FastAPI()


class Model(BaseModel):
    param: str = Field(alias="param_alias")


@app.get("/query")
async def query_model(data: Model = Query()):
    return {"param": data.param}


@app.get("/header")
async def header_model(data: Model = Header()):
    return {"param": data.param}


@app.get("/cookie")
async def cookie_model(data: Model = Cookie()):

	return c.client.Version(ctx)
}

func (c *kesConn) APIs(ctx context.Context) ([]madmin.KMSAPI, error) {
	APIs, err := c.client.APIs(ctx)
	if err != nil {
		if errors.Is(err, kes.ErrNotAllowed) {
			return nil, ErrPermission
		}
		return nil, Error{
			Code:    http.StatusInternalServerError,
			APICode: "kms:InternalError",
			Err:     "failed to list KMS APIs",
			Cause:   err,
		}
	}

Und Ihre **FastAPI**-Anwendung könnte auch aus mehreren Dateien/Modulen, usw. bestehen.

### **FastAPI** Anwendungsdatei { #fastapi-app-file }

Nehmen wir an, Sie haben eine Dateistruktur wie in [Größere Anwendungen](bigger-applications.md){.internal-link target=_blank} beschrieben:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In der Datei `main.py` haben Sie Ihre **FastAPI**-Anwendung: