int iterations = 100000;
      int nKeys = keys.size();
      int[] deltas = new int[nKeys];
      Operation[] operations = Operation.values();
      for (int i = 0; i < iterations; i++) {
        int keyIndex = random.nextInt(nKeys);
        String key = keys.get(keyIndex);
        Operation op = operations[random.nextInt(operations.length)];
        switch (op) {
          case ADD:
            {

...le "path" serait :

```
/items/foo
```

/// info

Un chemin, ou "path" est aussi souvent appelé route ou "endpoint".

///

#### Opération

"Opération" fait référence à une des "méthodes" HTTP.

Une de :

* `POST`
* `GET`
* `PUT`
* `DELETE`

...ou une des plus exotiques :

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry?

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

Then, declare your *path operation functions* with `async def` like:

🆎 🈸 👆 💪 💚 🚮 🔗 🎂 🈸.

🎏 🌌 👆 💪 [🚮 `dependencies` *➡ 🛠️ 👨‍🎨*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, 👆 💪 🚮 👫 `FastAPI` 🈸.

👈 💼, 👫 🔜 ✔ 🌐 *➡ 🛠️* 🈸:

```Python hl_lines="15"
{!../../docs_src/dependencies/tutorial012.py!}
```

& 🌐 💭 📄 🔃 [❎ `dependencies` *➡ 🛠️ 👨‍🎨*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank} ✔, ✋️ 👉 💼, 🌐 *➡ 🛠️* 📱.

## 🔗 👪 *➡ 🛠️*

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can perform a {@link #tearDown} operation.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TearDown {
  /**
   * Performs a <b>single</b> tear-down operation. See test-libraries-for-java's {@code
   * com.google.common.testing.junit3.TearDownTestCase} and {@code

# 전역 의존성

몇몇 애플리케이션에서는 애플리케이션 전체에 의존성을 추가하고 싶을 수 있습니다.

[*경로 작동 데코레이터*에 `dependencies` 추가하기](dependencies-in-path-operation-decorators.md){.internal-link target=_blank}와 유사한 방법으로 `FastAPI` 애플리케이션에 그것들을 추가할 수 있습니다.

그런 경우에, 애플리케이션의 모든 *경로 작동*에 적용될 것입니다:

//// tab | Python 3.9+

```Python hl_lines="16"
{!> ../../docs_src/dependencies/tutorial012_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="16"

    public void setRootLoggerLevel(Level level) {
        LOGGER.warn("setRootLoggerLevel: operation not supported");
    }

    public void activate() {
        LOGGER.warn("activate(): operation not supported");
    }

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception

Logo, a seção com:

{% raw %}

```jinja
<a href="{{ url_for('read_item', id=id) }}">
```

{% endraw %}

...irá gerar um link para a mesma URL que será tratada pela *path operation function* `read_item(id=id)`.

Por exemplo, com um ID de `42`, isso renderizará:

```html

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception