from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial002 import app

client = TestClient(app)


def test_get():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [{"item_id": "Foo"}]


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

`FastAPI` is a class that inherits directly from `Starlette`.

You can use all the <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> functionality with `FastAPI` too.

///

### Step 2: create a `FastAPI` "instance"

{* ../../docs_src/first_steps/tutorial001.py hl[3] *}

Here the `app` variable will be an "instance" of the class `FastAPI`.

/// note | "Заметка"

FastAPI понимает, что значение параметра `q` не является обязательным, потому что имеет значение по умолчанию `= None`.

Аннотация `Optional` в `Optional[str]` не используется FastAPI, но помогает вашему редактору лучше понимать ваш код и обнаруживать ошибки.

///

## Без Pydantic

from typing import List, Optional

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

from .utils import PYDANTIC_V2, needs_pydanticv2


class SubItem(BaseModel):
    subname: str
    sub_description: Optional[str] = None
    tags: List[str] = []
    if PYDANTIC_V2:
        model_config = {"json_schema_serialization_defaults_required": True}


class Item(BaseModel):

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial006c import app

client = TestClient(app)


def test_redirect_status_code():
    response = client.get("/pydantic", follow_redirects=False)
    assert response.status_code == 302
    assert response.headers["location"] == "https://docs.pydantic.dev/"


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

from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial005 import app

client = TestClient(app)


def test_get():
    response = client.get("/items/")
    assert response.status_code == 200, response.text


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

# Oauth2️⃣ ↔

👆 💪 ⚙️ Oauth2️⃣ ↔ 🔗 ⏮️ **FastAPI**, 👫 🛠️ 👷 💎.

👉 🔜 ✔ 👆 ✔️ 🌖 👌-🧽 ✔ ⚙️, 📄 Oauth2️⃣ 🐩, 🛠️ 🔘 👆 🗄 🈸 (& 🛠️ 🩺).

Oauth2️⃣ ⏮️ ↔ 🛠️ ⚙️ 📚 🦏 🤝 🐕‍🦺, 💖 👱📔, 🇺🇸🔍, 📂, 🤸‍♂, 👱📔, ♒️. 👫 ⚙️ ⚫️ 🚚 🎯 ✔ 👩‍💻 & 🈸.

🔠 🕰 👆 "🕹 ⏮️" 👱📔, 🇺🇸🔍, 📂, 🤸‍♂, 👱📔, 👈 🈸 ⚙️ Oauth2️⃣ ⏮️ ↔.

👉 📄 👆 🔜 👀 ❔ 🛠️ 🤝 & ✔ ⏮️ 🎏 Oauth2️⃣ ⏮️ ↔ 👆 **FastAPI** 🈸.

/// warning

# 学習

ここでは、**FastAPI** を学習するための入門セクションとチュートリアルを紹介します。

from fastapi.responses import PlainTextResponse
from fastapi.testclient import TestClient

from docs_src.advanced_middleware.tutorial003 import app


@app.get("/large")
async def large():
    return PlainTextResponse("x" * 4000, status_code=200)


client = TestClient(app)


def test_middleware():
    response = client.get("/large", headers={"accept-encoding": "gzip"})
    assert response.status_code == 200, response.text

```

## Advanced description from docstring

You can limit the lines used from the docstring of a *path operation function* for OpenAPI.

Adding an `\f` (an escaped "form feed" character) causes **FastAPI** to truncate the output used for OpenAPI at this point.

It won't show up in the documentation, but other tools (such as Sphinx) will be able to use the rest.

```Python hl_lines="19-29"