from inline_snapshot import snapshot
from pydantic import BaseModel

app = FastAPI()

reusable_oauth2 = OAuth2(
    flows={
        "password": {
            "tokenUrl": "token",
            "scopes": {"read:users": "Read the users", "write:users": "Create users"},
        }
    },
    description="OAuth2 security scheme",
    auto_error=False,
)


class User(BaseModel):
    username: str

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": False})


@app.get("/users/{username}")
async def read_user(username: str):

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"deepLinking": False})


@app.get("/users/{username}")
async def read_user(username: str):

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": {"theme": "obsidian"}})


@app.get("/users/{username}")
async def read_user(username: str):

* Asignar ese resultado al parámetro en tu *path operation function*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

De esta manera escribes código compartido una vez y **FastAPI** se encarga de llamarlo para tus *path operations*.

/// check | Revisa

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


@router.get("/users/{id}")
def read_user(segment: str, id: str):
    return {"segment": segment, "id": id}


app.include_router(router, prefix="/{segment}")


client = TestClient(app)


def test_get():
    response = client.get("/seg/users/foo")

from fastapi import FastAPI

app = FastAPI()


@app.get("/users/me")
async def read_user_me():
    return {"user_id": "the current user"}


@app.get("/users/{user_id}")
async def read_user(user_id: str):

* Bu sonucu *path operation function*'ınızdaki parametreye atar.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

Bu şekilde paylaşılan kodu bir kez yazarsınız ve onu *path operation*'larda çağırma işini **FastAPI** halleder.

/// check | Ek bilgi

    return get_redoc_html(
        openapi_url=app.openapi_url,
        title=app.title + " - ReDoc",
        redoc_js_url="/static/redoc.standalone.js",
    )


@app.get("/users/{username}")
async def read_user(username: str):

    return "alice", required_scopes.scopes


def get_data():
    return [1, 2, 3]


def get_data_override():
    return [3, 4, 5]


@app.get("/user")
def read_user(
    user_data: tuple[str, list[str]] = Security(get_user, scopes=["foo", "bar"]),
    data: list[int] = Depends(get_data),
):
    return {"user": user_data[0], "scopes": user_data[1], "data": data}