## Example

    ```python
    from fastapi import FastAPI, HTTPException

    app = FastAPI()

    items = {"foo": "The Foo Wrestlers"}


    @app.get("/items/{item_id}")
    async def read_item(item_id: str):
        if item_id not in items:
            raise HTTPException(status_code=404, detail="Item not found")

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


@app.put("/items/{item_id}")
async def update_item(

from datetime import datetime, time, timedelta
from typing import Annotated, Union
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: Annotated[datetime, Body()],
    end_datetime: Annotated[datetime, Body()],
    process_after: Annotated[timedelta, Body()],
    repeat_at: Annotated[Union[time, None], Body()] = None,
):

</div>

➡️ 👀 ⚫️❔ 🔠 👈 🎛 ⛓:

* `main:app`: 👉 🎏 ❕ ⚙️ Uvicorn, `main` ⛓ 🐍 🕹 📛 "`main`",, 📁 `main.py`. &amp; `app` 📛 🔢 👈 **FastAPI** 🈸.
    * 👆 💪 🌈 👈 `main:app` 🌓 🐍 `import` 📄 💖:

        ```Python
        from main import app
        ```

    * , ❤ `main:app` 🔜 🌓 🐍 `import` 🍕 `from main import app`.
* `--workers`: 🔢 👨‍🏭 🛠️ ⚙️, 🔠 🔜 🏃 Uvicorn 👨‍🏭, 👉 💼, 4️⃣ 👨‍🏭.
* `--worker-class`: 🐁-🔗 👨‍🏭 🎓 ⚙️ 👨‍🏭 🛠️.

 */
package org.codelibs.fess.app.web.admin.role;

import java.util.Base64;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.Constants;
import org.codelibs.fess.annotation.Secured;
import org.codelibs.fess.app.pager.RolePager;
import org.codelibs.fess.app.service.RoleService;
import org.codelibs.fess.app.web.CrudMode;

        return {"item_id": item_id}
    else:
        return {"item_id": item_id, "user_id": user_id}


app.include_router(user_router, prefix="/users")
app.include_router(item_router, prefix="/items")

app.include_router(item_router, prefix="/users/{user_id}/items")


client = TestClient(app)


def test_get_users():
    """Check that /users returns expected data"""
    response = client.get("/users")

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial006b import app

client = TestClient(app)


def test_redirect_response_class():
    response = client.get("/fastapi", follow_redirects=False)
    assert response.status_code == 307
    assert response.headers["location"] == "https://fastapi.tiangolo.com"


def test_openapi_schema():
    response = client.get("/openapi.json")

from typing import Annotated, Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[
        Union[str, None],
        Query(
            alias="item-query",
            title="Query string",
            description="Query string for the items to search in the database that have a good match",
            min_length=3,
            max_length=50,

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


@app.put("/items/{item_id}")

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: str | None = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons=Depends(CommonQueryParams)):
    response = {}
    if commons.q: