}

	// Collect all identifiers by name.
	idents := make(map[string][]*syntax.Name)
	syntax.Inspect(f, func(n syntax.Node) bool {
		if id, ok := n.(*syntax.Name); ok {
			idents[id.Value] = append(idents[id.Value], id)
		}
		return true
	})

	for _, test := range tests {
		test := test
		t.Run(test.name, func(t *testing.T) {
			if got := len(idents[test.name]); got != 1 {

// ----------------------------------------------------------------------------
// Convenience functions for Idents

// NewIdent creates a new [Ident] without position.
// Useful for ASTs generated by code other than the Go parser.
func NewIdent(name string) *Ident { return &Ident{token.NoPos, name, nil} }

// IsExported reports whether name starts with an upper-case letter.

	// can only appear in qualified identifiers which are mapped to
	// selector expressions.
	if ident, ok := e.X.(*ast.Ident); ok {
		obj := check.lookup(ident.Name)
		if pname, _ := obj.(*PkgName); pname != nil {
			assert(pname.pkg == check.pkg)
			check.recordUse(ident, pname)
			pname.used = true
			pkg := pname.imported

			var exp Object
			funcMode := value
			if pkg.cgo {

// if src ends in a trailing newline, so will dst.
func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
	dst.Grow(indentGrowthFactor * len(src))
	b := dst.AvailableBuffer()
	b, err := appendIndent(b, src, prefix, indent)
	dst.Write(b)
	return err
}

func appendIndent(dst, src []byte, prefix, indent string) ([]byte, error) {
	origLen := len(dst)
	scan := newScanner()

	c.bool = c.Ident("bool")
	c.byte = c.Ident("byte")
	c.int8 = c.Ident("int8")
	c.int16 = c.Ident("int16")
	c.int32 = c.Ident("int32")
	c.int64 = c.Ident("int64")
	c.uint8 = c.Ident("uint8")
	c.uint16 = c.Ident("uint16")
	c.uint32 = c.Ident("uint32")
	c.uint64 = c.Ident("uint64")
	c.uintptr = c.Ident("uintptr")
	c.float32 = c.Ident("float32")
	c.float64 = c.Ident("float64")

	e.eventRecorder.Eventf(object, eventtype, reason, messageFmt, args...)
}

// Shutdown terminates the event recorder. This must be called upon completion of writing events, and events should not be
// written once terminated.
func (e *EventRecorder) Shutdown() {
	e.eventBroadcaster.Shutdown()

![Events Diagram](../assets/images/events@2x.png)

```Python hl_lines="22"
{!../../../docs_src/events/tutorial003.py!}
```

## Alternative Events (deprecated)

!!! warning
    The recommended way to handle the *startup* and *shutdown* is using the `lifespan` parameter of the `FastAPI` app as described above. If you provide a `lifespan` parameter, `startup` and `shutdown` event handlers will no longer be called. It's all `lifespan` or all events, not both.

    You can probably skip this part.

使用 `startup` 事件声明 `app` 启动前运行的函数：

```Python hl_lines="8"
{!../../../docs_src/events/tutorial001.py!}
```

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

只有所有 `startup` 事件处理器运行完毕，**FastAPI** 应用才开始接收请求。

## `shutdown` 事件

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

```Python hl_lines="22"
{!../../../docs_src/events/tutorial003.py!}
```

## Alternative Events (deprecated)

!!! warning "Achtung"