////

### Erforderlich mit Ellipse (`...`)

Es gibt eine Alternative, die explizit deklariert, dass ein Wert erforderlich ist. Sie können als Default das <abbr title='Zeichenfolge, die einen Wert direkt darstellt, etwa 1, "hallowelt", True, None'>Literal</abbr> `...` setzen:

//// tab | Python 3.9+

```Python hl_lines="9"
{!> ../../docs_src/query_params_str_validations/tutorial006b_an_py39.py!}
```

////

where <code>T</code> is not a pointer or interface type,
<code>x.f</code> denotes the field or method at the shallowest depth
in <code>T</code> where there
is such an <code>f</code>.
If there is not exactly <a href="#Uniqueness_of_identifiers">one <code>f</code></a>
with shallowest depth, the selector expression is illegal.
</li>

<li>
For a value <code>x</code> of type <code>I</code> where <code>I</code>

where <code>T</code> is not a pointer or interface type,
<code>x.f</code> denotes the field or method at the shallowest depth
in <code>T</code> where there is such an <code>f</code>.
If there is not exactly <a href="#Uniqueness_of_identifiers">one <code>f</code></a>
with shallowest depth, the selector expression is illegal.
</li>

<li>
For a value <code>x</code> of type <code>I</code> where <code>I</code>