* по пути `/`
* с использованием <abbr title="метод HTTP GET"><code>get</code> операции</abbr>

/// info | Информация о `@decorator`

Синтаксис `@something` в Python называется «декоратор».

Его размещают над функцией. Как красивая декоративная шляпа (кажется, отсюда и пошёл термин).

«Декоратор» берёт функцию ниже и делает с ней что-то.

{* ../../docs_src/settings/tutorial001_py39.py hl[2,5:8,11] *}

/// tip

If you want something quick to copy and paste, don't use this example, use the last one below.

///

`@app.get("/")` 告诉 **FastAPI** 在它下方的函数负责处理如下访问请求：

* 请求路径为 `/`
* 使用 <abbr title="HTTP GET 方法"><code>get</code> 操作</abbr>

/// info | `@decorator` Info

`@something` 语法在 Python 中被称为「装饰器」。

像一顶漂亮的装饰帽一样，将它放在一个函数的上方（我猜测这个术语的命名就是这么来的）。

装饰器接收位于其下方的函数并且用它完成一些工作。

在我们的例子中，这个装饰器告诉 **FastAPI** 位于其下方的函数对应着**路径** `/` 加上 `get` **操作**。

它是一个「**路径操作装饰器**」。

///

These particular phases in a plugin’s lifecycle can probably be generalized to all plugins so could be something implemented in all plugins. Here we could have the descriptor either point to methods for each of these phases to execute or we could create a lifecycle in Plexus for these phases.

* `Field(index=True)` tells SQLModel that it should create a **SQL index** for this column, that would allow faster lookups in the database when reading data filtered by this column.

    SQLModel will know that something declared as `str` will be a SQL column of type `TEXT` (or `VARCHAR`, depending on the database).

### Create an Engine { #create-an-engine }

                    result.addMissingArtifact(artifact);
                }
            } catch (ArtifactResolutionException e) {
                // This is really a wagon TransferFailedException so something went wrong after we successfully
                // retrieved the metadata.

                synchronized (result) {
                    result.addErrorArtifactException(e);
                }

        if (submittingTaskQueue.thread == submitting) {
          sequencer = null;
          // Submit from inside a reentrant submit. We don't know if this one will be reentrant (and
          // can't know without submitting something to the executor) so queue to run iteratively.
          // Task must be null, since each execution on this executor can only produce one more
          // execution.
          checkState(submittingTaskQueue.nextTask == null);

You saw that you can use dependencies with `yield` and have `try` blocks that try to execute some code and then run some exit code after `finally`.

You can also use `except` to catch the exception that was raised and do something with it.

For example, you can raise a different exception, like `HTTPException`.

/// tip

   */
  protected final class MultiExceptionListIterator implements ListIterator<E> {
    // TODO: track seen elements when order isn't guaranteed
    // TODO: verify contents afterward
    // TODO: something shiny and new instead of Stack
    // TODO: test whether null is supported (create a Feature)
    /**
     * The elements to be returned by future calls to {@code next()}, with the first at the top of
     * the stack.

						continue
					}
				} else {
					entries = append(entries, entry)
				}
				count++
			}

			if len(h.logCh) > 0 || len(globalBuffer) > 0 || count == 0 {
				// there is something in the log queue
				// process it first, even if we tickered
				// first, or we have not received any events
				// yet, still wait on it.
				continue
			}

			// If we are doing batching, we should wait