putValue(data, "Encoding", message.getEncoding());
            putValue(data, "File-Name", message.getFileName());
            putValue(data, "From", message.getFrom());
            putValue(data, "Line-Count", message.getLineCount());
            putValue(data, "Message-ID", message.getMessageID());
            putValue(data, "Message-Number", message.getMessageNumber());

  // that are not part of the Kubernetes system.
  // +optional
  repeated string externalIPs = 5;

  // Supports "ClientIP" and "None". Used to maintain session affinity.
  // Enable client IP based session affinity.
  // Must be ClientIP or None.
  // Defaults to None.
  // More info: https://kubernetes.io/docs/concepts/services-networking/service/#virtual-ips-and-service-proxies
  // +optional

labels.crawler_title_edit=General Configuration
labels.schedule=Schedule
labels.enabled=Enabled
labels.day_for_cleanup=Remove Documents Before
labels.day=Day(s)
labels.crawl_button_update=Update
labels.none=None
labels.crawling_thread_count=Simultaneous Crawler Config
labels.incremental_crawling=Check Last Modified
labels.search_log_enabled=Search Logging
labels.user_info_enabled=User Logging

  }

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

    List<Character> one = Arrays.asList((char) 1);
    assertThat(Chars.toArray(one)).isEqualTo(ARRAY1);

    char[] array = {(char) 0, (char) 1, 'A'};

              // if a file already exists, that's fine... just continue
            }

            try {
              method.delete(dirToDelete);
            } catch (FileSystemException expected) {
              // the delete method may or may not throw an exception, but if it does that's fine
              // and expected
            }

```

</div>

////

/// tip

Every time you install a **new package** in that environment, **activate** the environment again.

This makes sure that if you use a **terminal (<abbr title="command line interface">CLI</abbr>) program** installed by that package, you use the one from your virtual environment and not any other that could be installed globally, probably with a different version than what you need.

///

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:

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
```

```

/// 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。

  // For many clients the singular form of the resource will be more understandable to users reading messages and should be used when integrating the name of the resource into a sentence.
  // The command line tool kubectl, for example, allows use of the singular resource name in place of plurals.
  // The singular form of a resource should always be an optional element - when in doubt use the canonical resource name.