# Sobre

///

**FastAPI**는 모두 Pydantic을 기반으로 되어 있습니다.

이 모든 것이 실제로 어떻게 사용되는지에 대해서는 [자습서 - 사용자 안내서](tutorial/index.md){.internal-link target=_blank} 에서 더 많이 확인하실 수 있습니다.

## **FastAPI**에서의 타입 힌트

**FastAPI**는 여러 부분에서 타입 힌트의 장점을 취하고 있습니다.

**FastAPI**에서 타입 힌트와 함께 매개변수를 선언하면 장점은:

* **에디터 도움**.
* **타입 확인**.

...그리고 **FastAPI**는 같은 정의를 아래에도 적용합니다:

与确保应用程序在启动时运行类似，您可能还想确保它在挂掉后**重新启动**。

### 我们会犯错误

作为人类，我们总是会犯**错误**。 软件几乎*总是*在不同的地方隐藏着**bug**。 🐛

作为开发人员，当我们发现这些bug并实现新功能（也可能添加新bug😅）时，我们会不断改进代码。

### 自动处理小错误

使用 FastAPI 构建 Web API 时，如果我们的代码中存在错误，FastAPI 通常会将其包含到触发错误的单个请求中。 🛡

对于该请求，客户端将收到 **500 内部服务器错误**，但应用程序将继续处理下一个请求，而不是完全崩溃。

### 更大的错误 - 崩溃

尽管如此，在某些情况下，我们编写的一些代码可能会导致整个应用程序崩溃，从而导致 Uvicorn 和 Python 崩溃。 💥

import importlib

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from tests.utils import needs_py39, needs_py310, needs_pydanticv1, needs_pydanticv2


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002", marks=needs_pydanticv2),
        pytest.param("tutorial002_py39", marks=[needs_py39, needs_pydanticv2]),

from typing import Optional

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

app = FastAPI()


user_router = APIRouter()
item_router = APIRouter()


@user_router.get("/")
def get_users():
    return [{"user_id": "u1"}, {"user_id": "u2"}]


@user_router.get("/{user_id}")
def get_user(user_id: str):
    return {"user_id": user_id}

from typing import Union

from dirty_equals import IsDict
from fastapi import Body, Cookie, FastAPI, Header, Path, Query
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    data: str


@app.post("/examples/")
def examples(
    item: Item = Body(
        examples=[
            {"data": "Data in Body examples, example1"},
        ],

from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial001 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

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.dataclasses.tutorial001 import app

client = TestClient(app)


def test_post_item():
    response = client.post("/items/", json={"name": "Foo", "price": 3})
    assert response.status_code == 200
    assert response.json() == {
        "name": "Foo",
        "price": 3,
        "description": None,
        "tax": None,
    }

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.dependencies.tutorial004 import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        (
            "/items",
            200,
            {
                "items": [
                    {"item_name": "Foo"},
                    {"item_name": "Bar"},

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.dependencies.tutorial004_an import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        (
            "/items",
            200,
            {
                "items": [
                    {"item_name": "Foo"},
                    {"item_name": "Bar"},