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

Por baixo dos panos, o código `open("./somefile.txt")` cria um objeto que é chamado de "Gerenciador de Contexto".

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

Underneath, the `open("./somefile.txt")` creates an object that is called a "Context Manager".

When the `with` block finishes, it makes sure to close the file, even if there were exceptions.

{* ../../docs_src/query_params/tutorial005_py39.py hl[6:7] *}

Here the query parameter `needy` is a required query parameter of type `str`.

If you open in your browser a URL like:

```
http://127.0.0.1:8000/items/foo-item
```

...without adding the required parameter `needy`, you will see an error like:

```JSON
{
  "detail": [
    {

	qa := qs.ActiveWorkers
	m.Set(replicationAverageActiveWorkers, float64(qa.Avg))
	m.Set(replicationCurrentActiveWorkers, float64(qa.Curr))
	m.Set(replicationMaxActiveWorkers, float64(qa.Max))

	if len(qs.XferStats) > 0 {
		tots := qs.XferStats[Total]
		m.Set(replicationAverageDataTransferRate, tots.Avg)
		m.Set(replicationCurrentDataTransferRate, tots.Curr)
		m.Set(replicationMaxDataTransferRate, tots.Peak)
	}

    private static byte[] buildExportName(Oid mech, String name) throws GSSException {
        byte[] der = mech.getDER();
        byte[] nb = name.getBytes();
        int len = 2 + 2 + der.length + 4 + nb.length;
        byte[] out = new byte[len];
        int i = 0;
        out[i++] = 0x04; // TOK_ID[0]
        out[i++] = 0x01; // TOK_ID[1]
        out[i++] = (byte) ((der.length >> 8) & 0xFF);

func (u Err) Msg(m string) Err {
	e := u.Clone()
	e.msg = m
	return e
}

// Msgf - Replace the current error's message
func (u Err) Msgf(m string, args ...any) Err {
	e := u.Clone()
	if len(args) == 0 {
		e.msg = m
	} else {
		e.msg = fmt.Sprintf(m, args...)
	}
	return e
}

// Hint - Replace the current error's message
func (u Err) Hint(m string, args ...any) Err {
	e := u.Clone()

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

Под капотом вызов `open("./somefile.txt")` создаёт объект, называемый «контекстным менеджером».

Когда блок `with` завершается, он обязательно закрывает файл, даже если были исключения.

      }

      connectionPool.evictAll()
      assertEquals(0, connectionPool.connectionCount()) {
        "Still ${connectionPool.connectionCount()} connections open"
      }
    }
  }

  private fun ensureAllTaskQueuesIdle() {
    val entryTime = System.nanoTime()

    for (queue in TaskRunner.INSTANCE.activeQueues()) {

					createTableSQL += ","
				}
			}

			if !hasPrimaryKeyInDataType && len(stmt.Schema.PrimaryFields) > 0 {
				createTableSQL += "PRIMARY KEY ?,"
				primaryKeys := make([]interface{}, 0, len(stmt.Schema.PrimaryFields))
				for _, field := range stmt.Schema.PrimaryFields {
					primaryKeys = append(primaryKeys, clause.Column{Name: field.DBName})
				}

That's why when talking about version 2.0 it's common to say "Swagger", and for version 3+ "OpenAPI".

/// check | Inspired **FastAPI** to

Adopt and use an open standard for API specifications, instead of a custom schema.

And integrate standards-based user interface tools:

* <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>