from typing import Annotated

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/")

* `Query` from `fastapi`
* `Annotated` from `typing`

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[1,3] *}

/// info

FastAPI added support for `Annotated` (and started recommending it) in version 0.95.0.

If you have an older version, you would get errors when trying to use `Annotated`.

Вы можете ограничить количество строк из docstring *функции-обработчика пути*, используемых для OpenAPI.

Добавление `\f` (экранированного символа «form feed») заставит **FastAPI** обрезать текст, используемый для OpenAPI, в этой точке.

Эта часть не попадёт в документацию, но другие инструменты (например, Sphinx) смогут использовать остальное.

/// note | 技术细节

你也可以使用`from starlette.responses import Response`或`from starlette.responses import JSONResponse`。

**FastAPI**提供了与`fastapi.responses`相同的`starlette.responses`，只是为了方便开发者。但是，大多数可用的响应都直接来自Starlette。

由于`Response`经常用于设置头部和cookies，因此**FastAPI**还在`fastapi.Response`中提供了它。

///

## 自定义头部

请注意，可以使用'X-'前缀添加自定义专有头部。

from typing import Annotated

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: str | None = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q

from typing import Union

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: Union[str, None] = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q

from typing import Annotated, Union

from fastapi import FastAPI, Path
from pydantic import BaseModel

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    item_id: Annotated[int, Path(title="The ID of the item to get", ge=0, le=1000)],
    q: Union[str, None] = None,

/// tip | Consejo

Hay un generador de proyectos oficial con **FastAPI** y **PostgreSQL** que incluye un frontend y más herramientas: <a href="https://github.com/fastapi/full-stack-fastapi-template" class="external-link" target="_blank">https://github.com/fastapi/full-stack-fastapi-template</a>

///

from typing import Annotated, Union

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from pydantic import BaseModel

fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "******@****.***",
        "hashed_password": "fakehashedsecret",
        "disabled": False,
    },
    "alice": {

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select


class Hero(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    age: int | None = Field(default=None, index=True)
    secret_name: str


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"