/// 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
```

        System.setProperty("custom.prop.one", "value1");
        System.setProperty("custom.prop.two", "value2");
        System.setProperty("other.property", "value3");

        // Test with regex pattern
        execJob.testAddFessCustomSystemProperties(cmdList, "custom\\.prop\\..*");

        assertEquals(2, cmdList.size());
        assertTrue(cmdList.contains("-Dcustom.prop.one=value1"));

          if (expectedMessage != null) {
            assertThat(expected).hasMessageThat().isEqualTo(expectedMessage);
          }
        }
      }
    },
    /*
     * This one comes last to work around b/367716565. (One *possible* alternative would be to not
     * declare any methods in this enum, converting assertFailsToDecode into a static method that is
     * implemented with a `switch`. I haven't tested that.)
     */

 * {@link Map} specified in the {@link Table} interface.
 *
 * <p>Note that this implementation is not synchronized. If multiple threads access this table
 * concurrently and one of the threads modifies the table, it must be synchronized externally.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#table">{@code Table}</a>.
 *

  }

  public void testRfc2202_hmacSha1_case7() {
    byte[] key = fillByteArray(80, 0xaa);
    String data = "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data";

    checkSha1("e8e99d0f45237d786d6bbaa7965c7808bbff1a91", key, data);
  }

  public void testRfc2202_hmacMd5_case1() {
    byte[] key = fillByteArray(16, 0x0b);
    String data = "Hi There";

    }

    /**
     * Construct a <code>Kerb5Authenticator</code> object with <code>Subject</code>
     * which hold TGT retrieved from KDC. If multiple TGT are contained, the
     * first one will be used to retrieve user principal.
     *
     * @param subject
     *            represents the user who perform Kerberos authentication.
     *            It contains tickets retrieve from KDC.
     */

        DirectoryCacheEntry entry = directoryCache.get(directoryPath);
        if (entry == null)
            return;

        // Handle lease break by updating cache behavior
        // Only process if newState is not NONE (0) - a valid lease state
        if (newState != 0) {
            if ((newState & Smb2LeaseState.SMB2_LEASE_READ_CACHING) == 0) {
                // Lost read cache - invalidate directory cache