You probably won't need to use it directly in your code.

But in case you needed it for an advanced scenario, you can add custom headers:

{* ../../docs_src/handling_errors/tutorial002_py39.py hl[14] *}

## Install custom exception handlers { #install-custom-exception-handlers }

      long k1 = 0;
      long k2 = 0;
      length += bb.remaining();
      switch (bb.remaining()) {
        case 15:
          k2 ^= (long) toUnsignedInt(bb.get(14)) << 48; // fall through
        case 14:
          k2 ^= (long) toUnsignedInt(bb.get(13)) << 40; // fall through
        case 13:
          k2 ^= (long) toUnsignedInt(bb.get(12)) << 32; // fall through
        case 12:

        configuration1.addChild(jdkHome1);
        tm1.setConfiguration(configuration1);

        ToolchainModel tm2 = new ToolchainModel();
        tm1.setType("jdk");
        tm1.addProvide("version", "1.4");
        tm1.addProvide("vendor", "sun");
        Xpp3Dom configuration2 = new Xpp3Dom("configuration");
        Xpp3Dom jdkHome2 = new Xpp3Dom("jdkHome");
        jdkHome2.setValue("${env.JAVA_HOME}");

pkg syscall (linux-386), const F_SETLEASE = 1024
pkg syscall (linux-386), const F_SETLK = 13
pkg syscall (linux-386), const F_SETLK64 = 13
pkg syscall (linux-386), const F_SETLKW = 14
pkg syscall (linux-386), const F_SETLKW64 = 14
pkg syscall (linux-386), const F_SETOWN = 8
pkg syscall (linux-386), const F_SETOWN_EX = 15
pkg syscall (linux-386), const F_SETPIPE_SZ = 1031
pkg syscall (linux-386), const F_SETSIG = 10

	{dataBlocks: 6, onDisks: 12, offDisks: 0, blocksize: int64(oneMiByte), data: oneMiByte, offset: oneMiByte, length: 0, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false},
	// 4
	{dataBlocks: 7, onDisks: 14, offDisks: 0, blocksize: int64(oneMiByte), data: oneMiByte, offset: 3, length: 1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false},                    // 5

            (byte) 26, (byte) 18, (byte) 10, (byte) 2, (byte) 59, (byte) 51, (byte) 43, (byte) 35, (byte) 62, (byte) 54, (byte) 46,
            (byte) 38, (byte) 30, (byte) 22, (byte) 14, (byte) 6, (byte) 61, (byte) 53, (byte) 45, (byte) 37, (byte) 29, (byte) 21,
            (byte) 13, (byte) 5, (byte) 60, (byte) 52, (byte) 44, (byte) 36, (byte) 28, (byte) 20, (byte) 12, (byte) 4, (byte) 27,

    assertTrue(range.encloses(Range.closed(3, 4)));

    assertFalse(range.encloses(Range.openClosed(2, 5)));
    assertFalse(range.encloses(Range.closedOpen(2, 5)));
    assertFalse(range.encloses(Range.closed(1, 4)));
    assertFalse(range.encloses(Range.closed(3, 6)));
    assertFalse(range.encloses(Range.greaterThan(3)));
    assertFalse(range.encloses(Range.lessThan(3)));
    assertFalse(range.encloses(Range.atLeast(3)));

**FastAPI** 能自动处理这些数据，并将之转换为 JSON。

///

## 添加自定义响应头

有些场景下要为 HTTP 错误添加自定义响应头。例如，出于某些方面的安全需要。

一般情况下可能不会需要在代码中直接使用响应头。

但对于某些高级应用场景，还是需要添加自定义响应头：

{* ../../docs_src/handling_errors/tutorial002.py hl[14] *}

## 安装自定义异常处理器

添加自定义处理器，要使用 [Starlette 的异常工具](https://www.starlette.dev/exceptions/)。

假设要触发的自定义异常叫作 `UnicornException`。

且需要 FastAPI 实现全局处理该异常。

此时，可以用 `@app.exception_handler()` 添加自定义异常控制器：

### Модель для входа { #model-for-input }

Если использовать эту модель как входную, как здесь:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

…то поле `description` **не будет обязательным**, потому что у него значение по умолчанию `None`.

### Входная модель в документации { #input-model-in-docs }

    static final int SHARING_DENY_READ_EXECUTE = 0x30;
    static final int SHARING_DENY_NONE = 0x40;

    static final int DO_NOT_CACHE = 0x1000; // bit 12
    static final int WRITE_THROUGH = 0x4000; // bit 14

    static final int OPEN_FN_CREATE = 0x10;
    static final int OPEN_FN_FAIL_IF_EXISTS = 0x00;
    static final int OPEN_FN_OPEN = 0x01;
    static final int OPEN_FN_TRUNC = 0x02;