* If you know Python types you know how to use Pydantic.
* Plays nicely with your **<abbr title="Integrated Development Environment: similar to a code editor">IDE</abbr>/<dfn title="A program that checks for code errors">linter</dfn>/brain**:
    * Because pydantic data structures are just instances of classes you define; auto-completion, linting, mypy and your intuition should all work properly with your validated data.
* Validate **complex structures**:

```

### Override the `HTTPException` error handler { #override-the-httpexception-error-handler }

The same way, you can override the `HTTPException` handler.

For example, you could want to return a plain text response instead of JSON for these errors:

{* ../../docs_src/handling_errors/tutorial004_py310.py hl[3:4,9:11,25] *}

/// note | Technical Details

* **更簡單**：
    * 不需要學習新的 micro-language 來定義結構。
    * 如果你知道 Python 型別，你就知道如何使用 Pydantic。
* 和你的 **<abbr title="Integrated Development Environment - 整合開發環境: 類似於程式碼編輯器">IDE</abbr>/<dfn title="檢查程式碼錯誤的程式">linter</dfn>/brain** 都能好好配合：
    * 因為 Pydantic 的資料結構其實就是你自己定義的類別實例，所以自動補齊、linting、mypy 以及你的直覺都能很好地在經過驗證的資料上發揮作用。
* 驗證**複雜結構**：
    * 使用 Pydantic 模型時，你可以把資料結構分層設計，並且用 Python 的 `List` 和 `Dict` 等型別來定義。

/// tip | İpucu

**Password**’ları bu şekilde ele alırsınız: alırsınız ama API’de geri döndürmezsiniz.

Ayrıca password değerlerini saklamadan önce **hash** etmelisiniz; **asla plain text olarak saklamayın**.

///

`HeroCreate` alanları:

* `name`
* `age`
* `secret_name`

{* ../../docs_src/sql_databases/tutorial002_an_py310.py ln[7:22] hl[21:22] *}

    ],
)

tf_cuda_library(
    name = "c_api_test_util",
    testonly = 1,
    srcs = ["c_api_test_util.cc"],
    hdrs = ["c_api_test_util.h"],
    visibility = [
        "//learning/brain:__subpackages__",
        "//tensorflow:__subpackages__",
    ],
    deps = [
        ":c_api",
        ":c_api_experimental",
        ":c_api_internal",
        "//tensorflow/c:c_test_util",

But if we use the same model for another *path operation*, we could be sending our user's passwords to every client.

/// danger

Never store the plain password of a user or send it in a response like this, unless you know all the caveats and you know what you are doing.

///

## Add an output model { #add-an-output-model }

                bufferIndex += ((AndXServerMessageBlock) this.andx).readAndXWireFormat(buffer, bufferIndex);
            } else {

                /*
                 * Just a plain smb. Read it as normal.
                 */

                buffer[bufferIndex++] = (byte) (this.andx.wordCount & 0xFF);

                if ((this.andx.wordCount != 0) && (this.andx.wordCount > 2)) {

    derived.cancel(false);
    assertTrue(primary.isCancelled());
    assertFalse(primary.wasInterrupted());
  }

  // catching() uses a plain Function, so there's no testCatching_resultCancelledAfterFallback().

  // catching() uses a plain Function, so there's no testCatching_nullInsteadOfFuture().

  // Some tests of the exceptionType parameter:

    derived.cancel(false);
    assertTrue(primary.isCancelled());
    assertFalse(primary.wasInterrupted());
  }

  // catching() uses a plain Function, so there's no testCatching_resultCancelledAfterFallback().

  // catching() uses a plain Function, so there's no testCatching_nullInsteadOfFuture().

  // Some tests of the exceptionType parameter:

app = FastAPI()


# Use async def when calling async code
@app.get("/async-items/")
async def read_async_items():
    data = await some_async_library.fetch_items()
    return data


# Use plain def when calling blocking/sync code or when in doubt
@app.get("/items/")
def read_items():
    data = some_blocking_library.fetch_items()
    return data
```