```

O parâmetro de consulta `q` é do tipo `Union[str, None]`, o que significa que é do tipo `str` mas que também pode ser `None`, e de fato, o valor padrão é `None`, então o FastAPI saberá que não é obrigatório.

!!! note "Observação"
    O FastAPI saberá que o valor de `q` não é obrigatório por causa do valor padrão `= None`.

=== "Python 3.10+"

    ```Python
    q: str | None = None
    ```

=== "Python 3.8+"

    ```Python
    q: Union[str, None] = None
    ```

Вот что мы получим, если обернём это в `Annotated`:

=== "Python 3.10+"

    ```Python
    q: Annotated[str | None] = None
    ```

=== "Python 3.8+"

    ```Python
    q: Annotated[Union[str, None]] = None
    ```

    ```

Der Query-Parameter `q` hat den Typ `Union[str, None]` (oder `str | None` in Python 3.10), was bedeutet, er ist entweder ein `str` oder `None`. Der Defaultwert ist `None`, also weiß FastAPI, der Parameter ist nicht erforderlich.

!!! note "Hinweis"
    FastAPI weiß nur dank des definierten Defaultwertes `=None`, dass der Wert von `q` nicht erforderlich ist

}

// ValuesValidate validates the values of the tree using the supplied Func
func ValuesValidate(validations map[string]ValidatorFunc, node any, path util.Path) (errs util.Errors) {
	pstr := path.String()
	scope.Debugf("ValuesValidate %s", pstr)
	vf := validations[pstr]
	if vf != nil {
		errs = util.AppendErrs(errs, vf(path, node))
	}

	nn, ok := node.(map[string]any)
	if !ok {
		// Leaf, nothing more to recurse.
		return errs
	}

Dmitri Shuralyov <******@****.***> 1697571594 -0400

Dmitri Shuralyov <******@****.***> 1697571594 -0400

TF_TString_Type TF_StringGetType(const TF_TString *str) {
  return TF_TString_GetType(str);
}

size_t TF_StringGetSize(const TF_TString *tstr) {
  return TF_TString_GetSize(tstr);
}

size_t TF_StringGetCapacity(const TF_TString *str) {
  return TF_TString_GetCapacity(str);
}

// limitations under the License.

#include "plugin.h"

#ifndef INJECTION_VERSION
#error INJECTION_VERSION must be defined
#endif // INJECTION_VERSION

#define xstr(s) str(s)
#define str(s) #s

// Boilderplate code to register the extension implementation.
static RegisterContextFactory register_HeaderInjector(CONTEXT_FACTORY(HeaderInjectorContext),

// get validation function for specified path
func getValidationFuncForPath(validations map[string]ValidatorFunc, path util.Path) (ValidatorFunc, bool) {
	pstr := path.String()
	// fast match
	if !strings.Contains(pstr, "[") && !strings.Contains(pstr, "]") {
		vf, ok := validations[pstr]
		return vf, ok
	}
	for p, vf := range validations {
		ps := strings.Split(p, ".")
		if len(ps) != len(path) {
			continue
		}

TF_CAPI_EXPORT extern const char *TF_StringGetDataPointer(
    const TF_TString *tstr);

TF_CAPI_EXPORT extern TF_TString_Type TF_StringGetType(const TF_TString *str);

TF_CAPI_EXPORT extern size_t TF_StringGetSize(const TF_TString *tstr);

TF_CAPI_EXPORT extern size_t TF_StringGetCapacity(const TF_TString *str);

TF_CAPI_EXPORT extern void TF_StringDealloc(TF_TString *tstr);

#ifdef __cplusplus
} /* end extern "C" */
#endif