Esto no es una limitación de **FastAPI**, es parte del protocolo HTTP.

///

## Subida de Archivos Opcional

Puedes hacer un archivo opcional utilizando anotaciones de tipos estándar y estableciendo un valor por defecto de `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` con Metadatos Adicionales

stackit.run
stackit.zone

// Staclar : https://staclar.com
// Submitted by Q Misell <******@****.***>
// Submitted by Matthias Merkel <******@****.***>
musician.io
novecore.site

// Standard Library : https://stdlib.com
// Submitted by Jacob Lee <******@****.***>
api.stdlib.com

// stereosense GmbH : https://www.involve.me
// Submitted by Florian Burmann <******@****.***>

labels.user_favorite_enabled=Favorietenlogboek
labels.web_api_json_enabled=JSON-antwoord
labels.app_value=Systeemeigenschap
labels.default_label_value=Standaardlabelwaarde
labels.default_sort_value=Standaard sorteerwaarde
labels.virtual_host_value=Virtuele host
labels.append_query_param_enabled=Zoekparameter toevoegen
labels.login_required=Inloggen vereist
labels.result_collapsed=Dubbele resultaten samenvouwen

- Starting in 1.31, `container_engine_t` was added to the list of allowed SELinux types in the baseline Pod Security Standard. ([#126165](https://github.com/kubernetes/kubernetes/pull/126165), [@haircommander](https://github.com/haircommander))

{* ../../docs_src/dependencies/tutorial001_02_an_py310.py hl[12,16,21] *}

/// tip | Consejo

Esto es solo Python estándar, se llama un "alias de tipo", en realidad no es específico de **FastAPI**.

Pero porque **FastAPI** está basado en los estándares de Python, incluido `Annotated`, puedes usar este truco en tu código. 😎

///

containers.\n  resize: vertical;\n}\n\nfieldset {\n  // Browsers set a default `min-width: min-content;` on fieldsets,\n  // unlike e.g. `<div>`s, which have `min-width: 0;` by default.\n  // So we reset that to ensure fieldsets behave more like a standard block element.\n  // See https://github.com/twbs/bootstrap/issues/12359\n  // and https://html.spec.whatwg.org/multipage/#the-fieldset-and-legend-elements\n  min-width: 0;\n  // Reset the default outline behavior of fieldsets so they don't affect...

    --hash=sha256:f8212564d49c50eb4565e502814f694e240c55551a5f1bc841d4fcaabb0a9b8a \
    --hash=sha256:ffa565331890b90056c01db69c0fe634a776f8019c143a5ae265f9c6bc4bd6d4
    # via -r ci/official/requirements_updater/requirements.in
zstandard==0.23.0 \
    --hash=sha256:034b88913ecc1b097f528e42b539453fa82c3557e414b3de9d5632c80439a473 \
    --hash=sha256:0a7f0804bb3799414af278e9ad51be25edf67f78f916e08afdb983e74161b916 \

    --hash=sha256:f8212564d49c50eb4565e502814f694e240c55551a5f1bc841d4fcaabb0a9b8a \
    --hash=sha256:ffa565331890b90056c01db69c0fe634a776f8019c143a5ae265f9c6bc4bd6d4
    # via -r ci/official/requirements_updater/requirements.in
zstandard==0.23.0 \
    --hash=sha256:034b88913ecc1b097f528e42b539453fa82c3557e414b3de9d5632c80439a473 \
    --hash=sha256:0a7f0804bb3799414af278e9ad51be25edf67f78f916e08afdb983e74161b916 \

    --hash=sha256:f8212564d49c50eb4565e502814f694e240c55551a5f1bc841d4fcaabb0a9b8a \
    --hash=sha256:ffa565331890b90056c01db69c0fe634a776f8019c143a5ae265f9c6bc4bd6d4
    # via -r ci/official/requirements_updater/requirements.in
zstandard==0.23.0 \
    --hash=sha256:034b88913ecc1b097f528e42b539453fa82c3557e414b3de9d5632c80439a473 \
    --hash=sha256:0a7f0804bb3799414af278e9ad51be25edf67f78f916e08afdb983e74161b916 \

`@lru_cache` es parte de `functools`, que es parte del library estándar de Python, puedes leer más sobre él en las <a href="https://docs.python.org/3/library/functools.html#functools.lru_cache" class="external-link" target="_blank">docs de Python para `@lru_cache`</a>.

## Resumen