*/
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }
    return copy;
  }

在这两种情况下，与您之前的框架相比，**FastAPI** 可能[仍然很快](index.md#_11){.internal-link target=_blank}。

### 依赖

这同样适用于[依赖](tutorial/dependencies/index.md){.internal-link target=_blank}。如果一个依赖是标准的 `def` 函数而不是 `async def`，它将被运行在外部线程池中。

### 子依赖

Чаще всего это простой файл `requirements.txt` с построчным перечислением библиотек и их версий.

При этом Вы, для выбора версий, будете использовать те же идеи, что упомянуты на странице [О версиях FastAPI](versions.md){.internal-link target=_blank}.

Ваш файл `requirements.txt` может выглядеть как-то так:

```
fastapi>=0.68.0,<0.69.0
pydantic>=1.8.0,<2.0.0
uvicorn>=0.15.0,<0.16.0
```

```Python hl_lines="11"
{!../../docs_src/path_params_numeric_validations/tutorial006.py!}
```

## 요약

`Query`, `Path`(아직 보지 못한 다른 것들도)를 사용하면 [쿼리 매개변수와 문자열 검증](query-params-str-validations.md){.internal-link target=_blank}에서와 마찬가지로 메타데이터와 문자열 검증을 선언할 수 있습니다.

그리고 숫자 검증 또한 선언할 수 있습니다:

* `gt`: 크거나(`g`reater `t`han)
* `ge`: 크거나 같은(`g`reater than or `e`qual)
* `lt`: 작거나(`l`ess `t`han)

Still, in both situations, chances are that **FastAPI** will [still be faster](index.md#performance){.internal-link target=_blank} than (or at least comparable to) your previous framework.

### Dependencies

The same applies for [dependencies](tutorial/dependencies/index.md){.internal-link target=_blank}. If a dependency is a standard `def` function instead of `async def`, it is run in the external threadpool.

Para entender mais sobre performance, veja a seção <a href="https://fastapi.tiangolo.com/benchmarks/" class="internal-link" target="_blank">Benchmarks</a>.

## Dependências opcionais

Usados por Pydantic:

import java.util.Date
import kotlin.test.assertFailsWith
import okhttp3.Cookie.Companion.parse
import okhttp3.Cookie.Companion.parseAll
import okhttp3.HttpUrl.Companion.toHttpUrl
import okhttp3.internal.UTC
import okhttp3.internal.http.MAX_DATE
import okhttp3.internal.parseCookie
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.assertThrows
import org.junit.jupiter.params.ParameterizedTest
import org.junit.jupiter.params.provider.ValueSource

/// check | "**FastAPI** 👍 ⚫️"

👑 🕸 💽 🏃 **FastAPI** 🈸.

👆 💪 🌀 ⚫️ ⏮️ 🐁, ✔️ 🔁 👁-🛠️ 💽.

✅ 🌅 ℹ [🛠️](deployment/index.md){.internal-link target=_blank} 📄.

///

## 📇 & 🚅

## Install `WebSockets`

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `websockets`:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets client

### In production

```

</div>

**強烈建議**你編寫或複製程式碼、進行修改並在本地端運行。

在編輯器中使用它，才能真正體會到 FastAPI 的好處，可以看到你只需編寫少量程式碼，以及所有的型別檢查、自動補齊等功能。

---

## 安裝 FastAPI

第一步是安裝 FastAPI。

確保你建立一個[虛擬環境](../virtual-environments.md){.internal-link target=_blank}，啟用它，然後**安裝 FastAPI**：

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

/// note