Das ist keine Limitation von **FastAPI**, sondern Teil des HTTP-Protokolls.

///

## Optionaler Datei-Upload { #optional-file-upload }

Sie können eine Datei optional machen, indem Sie Standard-Typannotationen verwenden und den Defaultwert auf `None` setzen:

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

///

## Zusätzliche Validierung { #additional-validation }

Wir werden sicherstellen, dass, obwohl `q` optional ist, wann immer es bereitgestellt wird, **seine Länge 50 Zeichen nicht überschreitet**.

### `Query` und `Annotated` importieren { #import-query-and-annotated }

Um dies zu erreichen, importieren Sie zuerst:

import re
import shutil
import subprocess
from html.parser import HTMLParser
from http.server import HTTPServer, SimpleHTTPRequestHandler
from multiprocessing import Pool
from pathlib import Path
from typing import Any, Optional, Union

import mkdocs.utils
import typer
import yaml
from jinja2 import Template
from ruff.__main__ import find_ruff_bin
from slugify import slugify as py_slugify

logging.basicConfig(level=logging.INFO)

            VersionRange versionRange,
            String type,
            String classifier,
            String scope,
            boolean optional) {
        return createArtifactX(groupId, artifactId, versionRange, type, classifier, scope, null, optional);
    }

    private Artifact createProjectArtifactX(String groupId, String artifactId, String version) {

  assertEquals("hello, world!", chat.messages());

  chat.loadMore();
  chat.loadMore();
  assertEquals(""
      + "hello, world!\n"
      + "sup, bra?\n"
      + "yo dog", chat.messages());

  // Optional: confirm that your app made the HTTP requests you were expecting.
  RecordedRequest request1 = server.takeRequest();
  assertEquals("/v1/chat/messages/", request1.getUrl().encodedPath());

     * @param realm Server realm
     * @param principalName Server principal name
     * @param encType Encryption type
     * @param encryptedData Encrypted data
     * @param unknownTag Optional unknown tag number to test error handling
     * @return A byte array representing the ticket
     * @throws IOException on encoding error
     */

    List<ArtifactVersion> getAvailableVersions();

    void setAvailableVersions(List<ArtifactVersion> versions);

    boolean isOptional();

    void setOptional(boolean optional);

    ArtifactVersion getSelectedVersion() throws OverConstrainedVersionException;

    boolean isSelectedVersionKnown() throws OverConstrainedVersionException;

      }
      val code =
        statusLine.substring(codeStart, codeStart + 3).toIntOrNull()
          ?: throw ProtocolException(
            "Unexpected status line: $statusLine",
          )

      // Parse an optional response message like "OK" or "Not Modified". If it
      // exists, it is separated from the response code by a space.
      var message = ""
      if (statusLine.length > codeStart + 3) {

import org.gradle.api.Describable
import org.gradle.api.provider.Property
import org.gradle.api.provider.ValueSource
import org.gradle.api.provider.ValueSourceParameters
import org.gradle.api.tasks.Optional
import java.text.SimpleDateFormat
import java.util.Date
import java.util.TimeZone


abstract class BuildTimestampValueSource : ValueSource<String, BuildTimestampValueSource.Parameters>, Describable {

    @ValidateTypeFailure
    public Integer crudMode;

    /** Configuration name for identifying this data source */
    @Required
    @Size(max = 200)
    public String name;

    /** Optional description of this data configuration */
    @Size(max = 1000)
    public String description;

    /** Handler class name for processing this data source */
    @Required