{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip

Here we use [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) instead of `time.time()` because it can be more precise for these use cases. 🤓

///

## Multiple middleware execution order { #multiple-middleware-execution-order }

也可以在產生出 `response` 之後、回傳之前執行程式碼。

例如，你可以新增一個自訂標頭 `X-Process-Time`，其內容為處理請求並產生回應所花費的秒數：

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip

這裡我們使用 [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) 而不是 `time.time()`，因為在這些用例中它可能更精確。🤓

///

## 多個中介軟體的執行順序 { #multiple-middleware-execution-order }

from fastapi import FastAPI, Request

app = FastAPI()


@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.perf_counter()
    response = await call_next(request)
    process_time = time.perf_counter() - start_time
    response.headers["X-Process-Time"] = str(process_time)

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip | Dica

Aqui usamos [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) em vez de `time.time()` porque ele pode ser mais preciso para esses casos de uso. 🤓

///

## Ordem de execução de múltiplos middlewares { #multiple-middleware-execution-order }

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip

Тут ми використовуємо [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) замість `time.time()` оскільки він може бути більш точним для таких випадків. 🤓

///

## Порядок виконання кількох middleware { #multiple-middleware-execution-order }

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip | Consejo

Aquí usamos [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) en lugar de `time.time()` porque puede ser más preciso para estos casos de uso. 🤓

///

## Orden de ejecución con múltiples middlewares { #multiple-middleware-execution-order }

也可以在生成 `response` 之后、返回之前添加代码。

例如，你可以添加一个自定义请求头 `X-Process-Time`，其值为处理请求并生成响应所花费的秒数：

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip

这里我们使用 [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) 而不是 `time.time()`，因为在这类场景中它可能更精确。🤓

///

## 多个中间件的执行顺序 { #multiple-middleware-execution-order }

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip | İpucu

Burada [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) yerine `time.time()` kullanıyoruz, çünkü bu kullanım senaryolarında daha hassas olabilir. 🤓

///

## Birden Fazla Middleware Çalıştırma Sırası { #multiple-middleware-execution-order }

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip | Совет

Мы используем [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) вместо `time.time()` для обеспечения большей точности в таких случаях. 🤓

///

## Порядок выполнения нескольких middleware { #multiple-middleware-execution-order }

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip | Astuce

Ici, nous utilisons [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) au lieu de `time.time()` car cela peut être plus précis pour ces cas d’usage. 🤓

///

## Ordre d’exécution de plusieurs middlewares { #multiple-middleware-execution-order }