Si necesitas usar algunas de las herramientas específicas de FastAPI para parámetros como `Body`, `Query`, `Form`, etc. con modelos de Pydantic v1, puedes importarlas de `fastapi.temp_pydantic_v1_params` mientras terminas la migración a Pydantic v2:

{* ../../docs_src/pydantic_v1_in_v2/tutorial004_an_py310.py hl[4,18] *}

### Migra por pasos { #migrate-in-steps }

/// tip | Consejo

Cuando instalas FastAPI (por ejemplo, con `pip install "fastapi[standard]"`), incluye un paquete llamado `fastapi-cli`, este paquete proporciona el comando `fastapi` en la terminal.

Para ejecutar tu aplicación FastAPI en modo de desarrollo, puedes usar el comando `fastapi dev`:

<div class="termy">

```console

        if (sneaky == null) {
          return sample;
        } else {
          /* Someone beat us to it! Trying again...
           *
           * Technically this loop not guaranteed to terminate, so theoretically (extremely
           * unlikely) this thread might starve, but even then, there is always going to be another
           * thread doing progress here.
           */
        }
      }
    }

    }

    /**
     * We use this to map all phases to the lifecycle that contains it. This is used so that a user can specify the
     * phase they want to execute, and we can easily determine what lifecycle we need to run.
     *
     * @return A map of lifecycles, indexed on id
     */
    public Map<String, Lifecycle> getPhaseToLifecycleMap() {
        if (logger.isDebugEnabled() && !lifecyclesPrinted) {

Aquí **FastAPI** no se confundirá porque estás usando `Depends`.

///

/// check | Revisa

El modo en que este sistema de dependencias está diseñado nos permite tener diferentes dependencias (diferentes "dependables") que todas devuelven un modelo `User`.

No estamos restringidos a tener solo una dependencia que pueda devolver ese tipo de datos.

///

   * {@code EnumHashBiMap} or an {@link EnumBiMap}, the new bimap has the same key type as the input
   * bimap. Otherwise, the specified map must contain at least one mapping, in order to determine
   * the key type.
   *
   * @param map the map whose mappings are to be placed in this map
   * @throws IllegalArgumentException if map is not an {@code EnumBiMap} or an {@code EnumHashBiMap}

   *
   * <p>Many of the filtered map's methods, such as {@code size()}, iterate across every key/value
   * mapping in the underlying map and determine which satisfy the filter. When a live view is
   * <i>not</i> needed, it may be faster to copy the filtered map and use the copy.
   *

   *
   * <p>Many of the filtered map's methods, such as {@code size()}, iterate across every key/value
   * mapping in the underlying map and determine which satisfy the filter. When a live view is
   * <i>not</i> needed, it may be faster to copy the filtered map and use the copy.
   *

      Comparator<? super E> comparator) {
    return new TreeSet<>(checkNotNull(comparator));
  }

  /**
   * Creates an empty {@code Set} that uses identity to determine equality. It compares object
   * references, instead of calling {@code equals}, to determine whether a provided object matches
   * an element in the set. For example, {@code contains} returns {@code false} when passed an

Se você estiver construindo uma aplicação <abbr title="Command Line Interface – Interface de Linha de Comando">CLI</abbr> para ser utilizada em um terminal ao invés de uma aplicação web, dê uma olhada no <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>.

**Typer** é o irmão menor do FastAPI. E seu propósito é ser o **FastAPI das _CLIs_**. ⌨️ 🚀