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"}

def test_path_operation():
    response = client.get("/headers-and-object/")
    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 | "Dica"

O segundo argumento para <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> é o valor padrão a ser retornado.

Se não for fornecido, é `None` por padrão, Aqui fornecemos `"World"` como o valor padrão a ser usado.

///

client = TestClient(app)


def test_path_operation():
    response = client.get("/headers/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}
    assert response.headers["X-Cat-Dog"] == "alone in the world"

</p>

<p>
For example, in this program:
</p>

<pre>
var a string

func f() {
	print(a)
}

func hello() {
	a = "hello, world"
	go f()
}
</pre>

<p>
calling <code>hello</code> will print <code>"hello, world"</code>
at some point in the future (perhaps after <code>hello</code> has returned).
</p>

<h3 id="goexit">Goroutine destruction</h3>

<p>

        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

{"text": "hello world\\n2nd line"}...

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

📨 🔜 🕳 💖:

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

### ⚒ `root_path` FastAPI 📱

👐, 🚥 👆 🚫 ✔️ 🌌 🚚 📋 ⏸ 🎛 💖 `--root-path` ⚖️ 🌓, 👆 💪 ⚒ `root_path` 🔢 🕐❔ 🏗 👆 FastAPI 📱:

```Python hl_lines="3"

    mac.init(SHA1_KEY);
    mac.update("hello".getBytes(UTF_8));
    mac.update("world".getBytes(UTF_8));

    assertEquals(
        HashCode.fromBytes(mac.doFinal()),
        Hashing.hmacSha1(SHA1_KEY)
            .newHasher()
            .putString("hello", UTF_8)
            .putString("world", UTF_8)
            .hash());
  }

  public void testMultipleUpdatesDoFinal() throws Exception {

		{
			objectName:         "test",
			data:               []byte("Hello, World"),
			expectedRespStatus: http.StatusForbidden,
			accessKey:          "",
			secretKey:          "",
			malformedBody:      false,
		},
		// Bad case malformed input.
		{
			objectName:         "test",
			data:               []byte("Hello, World"),
			expectedRespStatus: http.StatusBadRequest,