## Ready to Work { #ready-to-work }

Now you're ready to start working on your project.



/// tip

Do you want to understand what's all that above?

Continue reading. 👇🤓

///

## Why Virtual Environments { #why-virtual-environments }

To work with FastAPI you need to install [Python](https://www.python.org/).

We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:amqp`. To understand more about ARN please follow [AWS ARN](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) documentation.

```
mc mb myminio/images
mc event add myminio/images arn:minio:sqs::1:amqp --suffix .jpg

mouse--a mouse--O mouse!'  The Mouse looked at her rather
inquisitively, and seemed to her to wink with one of its little
eyes, but it said nothing.

  `Perhaps it doesn't understand English,' thought Alice; `I
daresay it's a French mouse, come over with William the
Conqueror.'  (For, with all her knowledge of history, Alice had
no very clear notion how long ago anything had happened.)  So she

To understand more about it, see the section [Benchmarks](https://fastapi.tiangolo.com/benchmarks/).

## Dependencies { #dependencies }

FastAPI depends on Pydantic and Starlette.

这在 Pydantic 2 或更高版本中可用。😎

///

/// tip | 提示

如果你需要进行任何需要与**外部组件**通信的校验，例如数据库或其他 API，你应该改用 **FastAPI 依赖项**，稍后你会学到它们。

这些自定义校验器用于只需检查请求中**同一份数据**即可完成的事情。

///

### 理解这段代码 { #understand-that-code }

关键点仅仅是：在 `Annotated` 中使用带函数的 **`AfterValidator`**。不感兴趣可以跳过这一节。🤸

---

但如果你对这个具体示例好奇，并且还愿意继续看，这里有一些额外细节。

#### 字符串与 `value.startswith()` { #string-with-value-startswith }

   * Integer#decode} and {@link Integer#toString()}. The returned converter throws {@link
   * NumberFormatException} if the input string is invalid.
   *
   * <p><b>Warning:</b> please see {@link Integer#decode} to understand exactly how strings are
   * parsed. For example, the string {@code "0123"} is treated as <i>octal</i> and converted to the
   * value {@code 83}.
   *
   * @since 16.0
   */

 *
 * <p>If you are unfamiliar with Bloom filters, this nice <a
 * href="http://llimllib.github.io/bloomfilter-tutorial/">tutorial</a> may help you understand how
 * they work.
 *
 * <p>The false positive probability ({@code FPP}) of a Bloom filter is defined as the probability
 * that {@linkplain #mightContain(Object)} will erroneously return {@code true} for an object that

  }

  private static <T extends @Nullable Object> List<Predicate<? super T>> asList(
      Predicate<? super T> first, Predicate<? super T> second) {
    // TODO(kevinb): understand why we still get a warning despite @SafeVarargs!
    return Arrays.<Predicate<? super T>>asList(first, second);
  }

  private static <T> List<T> defensiveCopy(T... array) {

To understand more about it, see the section [Benchmarks](https://fastapi.tiangolo.com/benchmarks/).

## Dependencies

FastAPI depends on Pydantic and Starlette.

### `standard` Dependencies

                 * behavior is undefined because of the concurrent mutation.)
                 *
                 * (Our prototype checker happens to be "smart" enough to understand this for the
                 * *get* call in getValue but not for the *put* call here.)
                 *
                 * (Arguably we should use requireNonNull rather than uncheckedCastNullableTToT: We