⤴️ 👆 🎏 👆 💯.

🤶 Ⓜ.:

* 🚶‍♀️ *➡* ⚖️ *🔢* 🔢, 🚮 ⚫️ 📛 ⚫️.
* 🚶‍♀️ 🎻 💪, 🚶‍♀️ 🐍 🎚 (✅ `dict`) 🔢 `json`.
* 🚥 👆 💪 📨 *📨 💽* ↩️ 🎻, ⚙️ `data` 🔢 ↩️.
* 🚶‍♀️ *🎚*, ⚙️ `dict` `headers` 🔢.
*  *🍪*, `dict` `cookies` 🔢.

🌖 ℹ 🔃 ❔ 🚶‍♀️ 💽 👩‍💻 (⚙️ `httpx` ⚖️ `TestClient`) ✅ <a href="https://www.python-httpx.org" class="external-link" target="_blank">🇸🇲 🧾</a>.

# Classes as Dependencies

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example

In the previous example, we were returning a `dict` from our dependency ("dependable"):

//// tab | Python 3.10+

```Python hl_lines="9"
{!> ../../docs_src/dependencies/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="11"

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.dict;

/**
 * @author Keiichi Watanabe
 */
public class ListForm {

Lá você pode definir:

* O "Item ID", usado na rota.
* O "Token" usado como um parâmetro de consulta.

/// tip | Dica

Perceba que a consulta `token` será manipulada por uma dependência.

///

Com isso você pode conectar o WebSocket e então enviar e receber mensagens:

<img src="/img/tutorial/websockets/image05.png">

@app.patch("/items/{item_id}", response_model=Item)
async def update_item(item_id: str, item: Item):
    stored_item_data = items[item_id]
    stored_item_model = Item(**stored_item_data)
    update_data = item.dict(exclude_unset=True)
    updated_item = stored_item_model.copy(update=update_data)
    items[item_id] = jsonable_encoder(updated_item)

from typing import Union

from fastapi import FastAPI, Response
from fastapi.responses import RedirectResponse

app = FastAPI()


@app.get("/portal")
async def get_portal(teleport: bool = False) -> Union[Response, dict]:
    if teleport:
        return RedirectResponse(url="https://www.youtube.com/watch?v=dQw4w9WgXcQ")

def fake_password_hasher(raw_password: str):
    return "supersecret" + raw_password


def fake_save_user(user_in: UserIn):
    hashed_password = fake_password_hasher(user_in.password)
    user_in_db = UserInDB(**user_in.dict(), hashed_password=hashed_password)
    print("User saved! ..not really")
    return user_in_db


@app.post("/user/", response_model=UserOut)
async def create_user(user_in: UserIn):

### Use the `app.dependency_overrides` attribute

For these cases, your **FastAPI** application has an attribute `app.dependency_overrides`, it is a simple `dict`.

To override a dependency for testing, you put as a key the original dependency (a function), and as the value, your dependency override (another function).

@app.get("/main-depends/")
async def main_depends(commons: dict = Depends(common_parameters)):
    return {"in": "main-depends", "params": commons}


@app.get("/decorator-depends/", dependencies=[Depends(common_parameters)])
async def decorator_depends():
    return {"in": "decorator-depends"}


@router.get("/router-depends/")
async def router_depends(commons: dict = Depends(common_parameters)):

def process_items(prices: dict[str, float]):
    for item_name, item_price in prices.items():
        print(item_name)