That way I could find the best ways to reduce code duplication as much as possible, to have completion everywhere, type and error checks, etc.

All in a way that provided the best development experience for all the developers.

## Requirements { #requirements }

    hashed_password = hashed_password,
)
```

/// warning | 警告

配套的辅助函数 `fake_password_hasher` 和 `fake_save_user` 仅用于演示可能的数据流，当然并不提供真实的安全性。

///

## 减少重复 { #reduce-duplication }

减少代码重复是 **FastAPI** 的核心思想之一。

代码重复会导致 bug、安全问题、代码失步等问题（更新了某个位置的代码，但没有同步更新其它位置的代码）。

上面的这些模型共享了大量数据，拥有重复的属性名和类型。

我们可以做得更好。

声明 `UserBase` 模型作为其它模型的基类。然后，用该类衍生出继承其属性（类型声明、校验等）的子类。

        // of A, B, C, and D, so when scanning B and D, E will be added again 'filtered'.
        //
        // Without de-duplication, the final list would contain E three times, once for E being in the projects and
        // whitelisted, and twice more for E being a downstream dependency of B and D.
        return filtered.stream().distinct().toList();
    }

     * again and get a more complete representation of the same object; but properties cannot be
     * removed, so this only allows limited reuse of the helper instance. The helper allows
     * duplication of properties (multiple name/value pairs with the same name can be added).
     */
    @Override
    public String toString() {
      // create a copy to keep it consistent in case value changes

Ek destek fonksiyonları olan `fake_password_hasher` ve `fake_save_user` sadece verinin olası bir akışını göstermek içindir; elbette gerçek bir güvenlik sağlamazlar.

///

## Tekrarı Azaltma { #reduce-duplication }

Kod tekrarını azaltmak, **FastAPI**'nin temel fikirlerinden biridir.

You just pass it to `Depends` and **FastAPI** knows how to do the rest.

///

## Share `Annotated` dependencies { #share-annotated-dependencies }

In the examples above, you see that there's a tiny bit of **code duplication**.

When you need to use the `common_parameters()` dependency, you have to write the whole parameter with the type annotation and `Depends()`:

```Python
commons: Annotated[dict, Depends(common_parameters)]
```

Вспомогательные дополнительные функции `fake_password_hasher` и `fake_save_user` используются только для демонстрации возможного потока данных и, конечно, не обеспечивают настоящую безопасность.

///

## Сократите дублирование { #reduce-duplication }

Сокращение дублирования кода — это одна из главных идей **FastAPI**.

As funções adicionais de suporte `fake_password_hasher` e `fake_save_user` servem apenas para demonstrar um fluxo possível dos dados, mas é claro que elas não fornecem segurança real.

///

## Reduzir duplicação { #reduce-duplication }

Reduzir a duplicação de código é uma das ideias principais no **FastAPI**.

      Multiset<Integer> get() {
        return Synchronized.multiset(HashMultiset.<Integer>create(), null);
      }
    },
    ;

    abstract Multiset<Integer> get();
  }

  /**
   * Duplication of the old version of ConcurrentHashMultiset (with some unused stuff removed, like
   * serialization code) which used a map with boxed integers for the values.
   */

Die unterstützenden zusätzlichen Funktionen `fake_password_hasher` und `fake_save_user` dienen nur zur Demo eines möglichen Datenflusses, bieten jedoch natürlich keine echte Sicherheit.

///

## Verdopplung vermeiden { #reduce-duplication }

Die Reduzierung von Code-Verdoppelung ist eine der Kernideen von **FastAPI**.