///

## Optional File Upload { #optional-file-upload }

You can make a file optional by using standard type annotations and setting a default value of `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` with Additional Metadata { #uploadfile-with-additional-metadata }

/// note

- 请注意，您必须直接使用 `FileResponse` 返回图像。

///

/// info

- 除非在 `responses` 参数中明确指定不同的媒体类型，否则**FastAPI**将假定响应与主响应类具有相同的媒体类型（默认为` application/json` ）。
- 但是如果您指定了一个自定义响应类，并将 `None `作为其媒体类型，**FastAPI**将使用 `application/json` 作为具有关联模型的任何其他响应。

///

## 组合信息
您还可以联合接收来自多个位置的响应信息，包括 `response_model `、 `status_code` 和 `responses `参数。

Isso não é uma limitação do **FastAPI**, é parte do protocolo HTTP.

///

## Upload de Arquivo Opcional

Você pode tornar um arquivo opcional usando anotações de tipo padrão e definindo um valor padrão de `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` com Metadados Adicionais

Você também pode usar `File()` com `UploadFile`, por exemplo, para definir metadados adicionais:

```

/// tip

آرگومان دوم <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> مقدار پیش‌فرضیه که برمی‌گردونه.

اگه ندی، به‌صورت پیش‌فرض `None` هست، اینجا ما `"World"` رو به‌عنوان مقدار پیش‌فرض گذاشتیم.

///

بعد می‌تونی اون برنامه پایتون رو صدا کنی:

//// tab | لینوکس، مک‌اواس، ویندوز بش

<div class="termy">

```console

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}
```

* Vous devriez maintenant avoir une structure de répertoire telle que :

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

PYTHON_VERSIONS=("python3.9" "python3.10" "python3.11" "python3.12")
for v in "${PYTHON_VERSIONS[@]}"; do
  ln -s "/usr/local/include/${v}" "/${TARGET}/usr/include/x86_64-linux-gnu/${v}"
done

# Patch glibc to be compatable with modern clang
case "${VERSION}" in
devtoolset-9)
  cd /
  patch -p0 < /glibc2.17-inline.patch
;;

			go func(i int, set *erasureObjects) {
				defer wg.Done()
				err := set.listPath(listCtx, o, innerResults)
				mu.Lock()
				defer mu.Unlock()
				if err == nil {
					allAtEOF = false
				}
				errs[i] = err
			}(len(errs), set)
			errs = append(errs, nil)
		}
	}
	mu.Unlock()

	// Gather results to a single channel.
	// Quorum is one since we are merging across sets.

                if (!dataCrawlingThreadList.get(i).isRunning() && Constants.RUNNING.equals(dataCrawlingThreadStatusList.get(i))) {
                    dataCrawlingThreadStatusList.set(i, Constants.DONE);
                }
                if (!Constants.DONE.equals(dataCrawlingThreadStatusList.get(i))) {
                    finishedAll = false;
                }
            }
        }
        dataCrawlingThreadList.clear();

    val cookieBuilder =
      Cookie
        .Builder()
        .name("a")
        .value("b")
        .domain("example.com")
        .sameSite("None")

    val cookie = cookieBuilder.build()
    assertThat(cookie.sameSite).isEqualTo("None")
  }

  @Test fun equalsAndHashCode() {
    val cookieStrings =
      Arrays.asList(
        "a=b; Path=/c; Domain=example.com; Max-Age=5; Secure; HttpOnly",

  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Double> none = Arrays.<Double>asList();
    assertThat(Doubles.toArray(none)).isEqualTo(EMPTY);

    List<Double> one = Arrays.asList(1.0);
    assertThat(Doubles.toArray(one)).isEqualTo(ARRAY1);

    double[] array = {0.0, 1.0, Math.PI};

    List<Double> three = Arrays.asList(0.0, 1.0, Math.PI);