```Python
with open("file.txt") as file:
    file.read()
```

En versiones recientes de Python, también hay un **async context manager**. Lo usarías con `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

///

////

/// info

Na versão 1 do Pydantic a configuração é realizada por uma classe interna `Config`, na versão 2 do Pydantic isso é feito com o atributo `model_config`. Esse atributo recebe um `dict`, para utilizar o autocomplete e checagem de erros do seu editor de texto você pode importar e utilizar `SettingsConfigDict` para definir esse `dict`.

///

Download a file on a worker thread, and get called back when the response is readable. The callback is made after the response headers are ready. Reading the response body may still block. OkHttp doesn't currently offer asynchronous APIs to receive a response body in parts.

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient()

      fun run() {
        val request = Request.Builder()

<div class="termy">

```console
$ cd ~/code/prisoner-of-azkaban

$ python main.py

// Error importing sirius, it's not installed 😱
Traceback (most recent call last):
    File "main.py", line 1, in <module>
        import sirius
```

</div>

import java.net.Proxy

/**
 * Listener for metrics events. Extend this class to monitor the quantity, size, and duration of
 * your application's HTTP calls.
 *
 * All start/connect/acquire events will eventually receive a matching end/release event, either
 * successful (non-null parameters), or failed (non-null throwable). The first common parameters of
 * each event pair are used to link the event in case of concurrent or repeated events e.g.

For example, if the **application server** is only receiving communication from the trusted **proxy**, you can set it to `--forwarded-allow-ips="*"` to make it trust all incoming IPs, as it will only receive requests from whatever is the IP used by the **proxy**.

This way the application would be able to know what is its own public URL, if it is using HTTPS, the domain, etc.

errors.property_type_double={0} è un numero double.
errors.property_type_date={0} è una data.

errors.storage_file_upload_failure=Caricamento di {0} fallito.
errors.storage_file_not_found=Il file di destinazione non è presente nell'archivio.
errors.storage_file_download_failure=Download di {0} fallito.
errors.storage_access_error=Errore di accesso all'archivio: {0}
errors.storage_no_upload_file=Specificare un file da caricare.

</pre>


<h3 id="Receive_operator">Receive operator</h3>

<p>
For an operand <code>ch</code> of <a href="#Channel_types">channel type</a>,
the value of the receive operation <code>&lt;-ch</code> is the value received
from the channel <code>ch</code>.
The channel direction must permit receive operations,
and the type of the receive operation is the element type of the channel.

    // Cause the cache trim job to fail.
    filesystem.setFaultyDelete(cacheDir / "a.0", true)
    taskFaker.runNextTask()

    // An edit should now add a job to clean up if the most recent trim failed.
    assertThat(cache.edit("b")).isNull()
    taskFaker.runNextTask()

    // Confirm a successful cache trim now allows edits.
    filesystem.setFaultyDelete(cacheDir / "a.0", false)

# Declare Request Example Data { #declare-request-example-data }

You can declare examples of the data your app can receive.

Here are several ways to do it.

## Extra JSON Schema data in Pydantic models { #extra-json-schema-data-in-pydantic-models }

You can declare `examples` for a Pydantic model that will be added to the generated JSON Schema.

//// tab | Pydantic v2

{* ../../docs_src/schema_extra_example/tutorial001_py310.py hl[13:24] *}