from fastapi import FastAPI
from fastapi.responses import JSONResponse

app = FastAPI()


@app.get("/headers/")
def get_headers():
    content = {"message": "Hello World"}
    headers = {"X-Cat-Dog": "alone in the world", "Content-Language": "en-US"}

router_b_a = APIRouter()
router_b_a_c_override = APIRouter()  # Overrides default class again


@app.get("/")
def get_root():
    return {"msg": "Hello World"}


@app.get("/override", response_class=PlainTextResponse)
def get_path_override():
    return "Hello World"


@router_a.get("/")
def get_a():
    return {"msg": "Hello A"}


@router_a.get("/override", response_class=PlainTextResponse)

@app.get("/orjson_non_str_keys")
def get_orjson_non_str_keys():
    key = quoted_name(value="msg", quote=False)
    return {key: "Hello World", 1: 1}


client = TestClient(app)


def test_orjson_non_str_keys():
    with client:
        response = client.get("/orjson_non_str_keys")

    }
  }

  @Test
  fun singlePart() {
    val expected =
      """
      |--123
      |
      |Hello, World!
      |--123--
      |
      """.trimMargin().replace("\n", "\r\n")
    val body =
      MultipartBody
        .Builder("123")
        .addPart("Hello, World!".toRequestBody(null))
        .build()
    assertThat(body.boundary).isEqualTo("123")

)
def test_router_events(state: State) -> None:
    app = FastAPI()

    @app.get("/")
    def main() -> dict[str, str]:
        return {"message": "Hello World"}

    @app.on_event("startup")
    def app_startup() -> None:
        state.app_startup = True

    @app.on_event("shutdown")
    def app_shutdown() -> None:
        state.app_shutdown = True

@app.get("/app")
def read_main(request: Request):
    return {"message": "Hello World", "root_path": request.scope.get("root_path")}


client = TestClient(app)


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")

        Did you *actually* encounter the need for this enhancement in a real-world scenario, or does
        it just seem like a sensible behavior for the feature to have?


        Before we make significant changes to existing features in Guava, we really want to be sure
        that it's for a use case that actually comes up in the real world. We want to hear the
        real-world use case so the community can discuss and debate whether this feature is actually

    [
        "/optional-list-bytes",
        "/optional-list-uploadfile",
    ],
)
def test_optional_list(path: str):
    client = TestClient(app)
    response = client.post(path, files=[("p", b"hello"), ("p", b"world")])
    assert response.status_code == 200
    assert response.json() == {"file_size": [5, 5]}


# =====================================================================================
# Alias

    assert response.json() == {"message": "Hello World"}
    assert (
        response.headers["access-control-allow-origin"]
        == "https://localhost.tiangolo.com"
    )

    # Test non-CORS response
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///