OAuth2는 backend 또는 API가 사용자를 인증하는 서버와 독립적일 수 있도록 설계되었습니다.

하지만 이 경우에는 같은 **FastAPI** 애플리케이션이 API와 인증을 모두 처리합니다.

따라서, 단순화된 관점에서 다시 정리해보면:

* 사용자가 frontend에서 `username`과 `password`를 입력하고 `Enter`를 누릅니다.
* frontend(사용자의 브라우저에서 실행됨)는 해당 `username`과 `password`를 우리 API의 특정 URL로 보냅니다(`tokenUrl="token"`로 선언됨).
* API는 `username`과 `password`를 확인하고 "token"으로 응답합니다(아직 아무것도 구현하지 않았습니다).

 * behavior</a> when multiple threads attempt concurrent mutations. Its equivalent to {@code
 * CacheBuilder} is its <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/Caffeine.html">{@code
 * Caffeine}</a> class. Caffeine offers better performance, more features (including asynchronous

     */
    public boolean isUsableForChannel() {
        return address != null && !address.isLoopbackAddress() && !address.isLinkLocalAddress();
    }

    /**
     * Get a score for interface selection (higher is better)
     *
     * @return interface score
     */
    public int getScore() {
        int score = linkSpeed; // Base score is link speed

        if (rssCapable)

The `str | None` is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

But adding the type annotations will allow your editor to give you better support and detect errors.

///

## Without Pydantic { #without-pydantic }

   *
   * @since 8.0
   */
  public static final byte ENQ = 5;

  /**
   * Acknowledge: A communication control character transmitted by a receiver as an affirmative
   * response to a sender.
   *
   * @since 8.0
   */
  public static final byte ACK = 6;

  /**
   * Bell ('\a'): A character for use when there is a need to call for human attention. It may

   * characters).
   *
   * @param c the character to escape
   * @return the replacement characters, or {@code null} if no escaping was required
   */
  // TODO(dbeaumont,cpovirk): Rename this something better once refactoring done
  protected abstract char @Nullable [] escapeUnsafe(char c);

Sonrasında, aşağıdaki gibi ek keyword argümanı `hashed_password=hashed_password` eklemek:

```Python
UserInDB(**user_in.model_dump(), hashed_password=hashed_password)
```

...şuna benzer bir sonuca dönüşür:

```Python
UserInDB(
    username = user_dict["username"],
    password = user_dict["password"],
    email = user_dict["email"],
    full_name = user_dict["full_name"],

Bu parametre bir `dict` alır: anahtarlar her response için status code'lardır (`200` gibi), değerler ise her birine ait bilgileri içeren başka `dict`'lerdir.

Bu response `dict`'lerinin her birinde, `response_model`'e benzer şekilde bir Pydantic model içeren `model` anahtarı olabilir.

**FastAPI** bu modeli alır, JSON Schema'sını üretir ve OpenAPI'de doğru yere ekler.

            * **FastAPI** adds a reference here to the global JSON Schemas in another place in your OpenAPI instead of including it directly. This way, other applications and clients can use those JSON Schemas directly, provide better code generation tools, etc.

///

The generated responses in the OpenAPI for this *path operation* will be:

```JSON hl_lines="3-12"
{
    "responses": {
        "404": {

   * This implementation requires O(|N|) time. Classes extending this one may manually keep track of
   * the number of edges as the graph is updated, and override this method for better performance.
   */
  protected long edgeCount() {
    long degreeSum = 0L;
    for (N node : nodes()) {
      degreeSum += degree(node);
    }