### Async Context Manager { #async-context-manager }

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

    * Isso é especialmente útil se você executar `await myfile.read()` uma vez e precisar ler o conteúdo novamente.
* `close()`: Fecha o arquivo.

Como todos esses métodos são métodos `assíncronos`, você precisa "aguardar" por eles.

Por exemplo, dentro de uma função de *operação de rota* `assíncrona`, você pode obter o conteúdo com:

```Python
contents = await myfile.read()
```

## Context Managers { #context-managers }

### What are "Context Managers" { #what-are-context-managers }

"Context Managers" are any of those Python objects that you can use in a `with` statement.

        default: "false"

env:
  UV_SYSTEM_PYTHON: 1

jobs:
  job:
    if: github.repository_owner == 'fastapi'
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      - uses: actions/checkout@v5
      - name: Set up Python

type BatchJobKeyRotateEncryption struct {
	Type       BatchKeyRotationType `yaml:"type" json:"type"`
	Key        string               `yaml:"key" json:"key"`
	Context    string               `yaml:"context" json:"context"`
	kmsContext kms.Context          `msg:"-"`
}

// Validate validates input key rotation encryption options.
func (e BatchJobKeyRotateEncryption) Validate() error {
	if e.Type != sses3 && e.Type != ssekms {

Você poderia criar uma classe `CustomORJSONResponse`. A principal coisa a ser feita é sobrecarregar o método render da classe Response, `Response.render(content)`, que retorna o conteúdo em bytes, para retornar o conteúdo que você deseja:

{* ../../docs_src/custom_response/tutorial009c.py hl[9:14,17] *}

Agora em vez de retornar:

```json
{"message": "Hello World"}
```

🖼, <a href="https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">👆 💪 ⚙️ `with` ✍ 📁</a>:

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

🔘, `open("./somefile.txt")` ✍ 🎚 👈 🤙 "🔑 👨‍💼".

🕐❔ `with` 🍫 🏁, ⚫️ ⚒ 💭 🔐 📁, 🚥 📤 ⚠.

🕐❔ 👆 ✍ 🔗 ⏮️ `yield`, **FastAPI** 🔜 🔘 🗜 ⚫️ 🔑 👨‍💼, &amp; 🌀 ⚫️ ⏮️ 🎏 🔗 🧰.

        default: "false"

env:
  UV_SYSTEM_PYTHON: 1

jobs:
  job:
    if: github.repository_owner == 'fastapi'
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      - uses: actions/checkout@v5
      - name: Set up Python

        default: "false"

env:
  UV_SYSTEM_PYTHON: 1

jobs:
  job:
    if: github.repository_owner == 'fastapi'
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      - uses: actions/checkout@v5
      - name: Set up Python

        // Test that multiple invocations return consistent results
        QueryContext context = new QueryContext("*:*", false);
        MatchAllDocsQuery query = new MatchAllDocsQuery();
        float boost = 1.0f;

        QueryBuilder result1 = matchAllQueryCommand.execute(context, query, boost);
        QueryBuilder result2 = matchAllQueryCommand.execute(context, query, boost);

        assertNotNull(result1);
        assertNotNull(result2);