app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: bool | None = None


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


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


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

#### Request a New Language

Let's say that you want to request translations for a language that is not yet translated, not even some pages. For example, Latin.

* The first step would be for you to find other 2 people that would be willing to be reviewing translation PRs for that language with you.

        // Note: isTarget requires FessConfig which needs container
        // We can only verify the method handles missing container gracefully
        try {
            generator.isTarget(docMap);
        } catch (IllegalStateException e) {
            // Expected when container is not initialized
            assertTrue(e.getMessage().contains("Not initialized"));
        }
    }

    @Test

        }

        if (retValue == null) {
            retValue = "/";
        }
        return retValue.trim();
    }

    /**
     * Decodes the specified (portion of a) URL. <strong>Note:</strong> This decoder assumes that ISO-8859-1 is used to
     * convert URL-encoded bytes to characters.
     *
     * @param url The URL to decode, may be <code>null</code>.

      create: true,
      owner: "vagrant"
  config.vm.synced_folder "#{Dir.home}/.gradle/wrapper", "/root/.gradle/wrapper",
      create: true,
      owner: "vagrant"

  # Expose project directory. Note that VAGRANT_CWD may not be the same as Dir.pwd
  PROJECT_DIR = ENV['VAGRANT_PROJECT_DIR'] || Dir.pwd
  config.vm.synced_folder PROJECT_DIR, '/project'

  'ubuntu-1604'.tap do |box|
    config.vm.define box, define_opts do |config|

  protected Map<K, V> delegate() {
    return delegate;
  }

  /** Returns its input, or throws an exception if this is not a valid key. */
  @CanIgnoreReturnValue
  @ParametricNullness
  K checkKey(@ParametricNullness K key) {
    return key;
  }

  /** Returns its input, or throws an exception if this is not a valid value. */
  @CanIgnoreReturnValue
  @ParametricNullness
  V checkValue(@ParametricNullness V value) {

	return n.Err
}

// Client - http based RPC client.
type Client struct {
	connected int32 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
	_         int32 // For 64 bits alignment
	lastConn  int64

	// HealthCheckFn is the function set to test for health.
	// If not set the client will not keep track of health.
	// Calling this returns true or false if the target
	// is online or offline.
	HealthCheckFn func() bool

   * the corresponding argument value from {@code args}; or, if the placeholder and argument counts
   * do not match, returns a best-effort form of that string. Will not throw an exception under
   * normal conditions.
   *
   * <p><b>Note:</b> For most string-formatting needs, use {@link String#format String.format},

你也可以为它声明带有各自模型、状态码等的附加响应。

文档中有一个完整章节，你可以阅读这里的[OpenAPI 中的附加响应](additional-responses.md)。

## OpenAPI Extra { #openapi-extra }

当你在应用中声明一个 *路径操作* 时，**FastAPI** 会自动生成与该 *路径操作* 相关的元数据，以包含到 OpenAPI 方案中。

/// note | 技术细节

在 OpenAPI 规范中，这被称为 [Operation 对象](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#operation-object)。

///

它包含关于该 *路径操作* 的所有信息，并用于生成自动文档。

  // Queues

  /**
   * A custom queue for managing eviction order. Note that this is tightly integrated with {@code
   * ReferenceEntry}, upon which it relies to perform its linking.
   *
   * <p>Note that this entire implementation makes the assumption that all elements which are in the
   * map are also in this queue, and that all elements not in the queue are not in the map.
   *