from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, user: User):

from typing import Annotated

from fastapi import Depends, FastAPI

app = FastAPI()


async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: Annotated[dict, Depends(common_parameters)]):
    return commons


@app.get("/users/")
async def read_users(commons: Annotated[dict, Depends(common_parameters)]):

from fastapi import FastAPI
from pydantic.v1 import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None

    class Config:
        schema_extra = {
            "examples": [
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,

**高级用户指南**中将介绍如何使用 `scopes`，及如何把 `scopes` 集成至 **FastAPI**。

## 小结

至此，您可以使用 OAuth2 和 JWT 等标准配置安全的 **FastAPI** 应用。

几乎在所有框架中，处理安全问题很快都会变得非常复杂。

有些包为了简化安全流，不得不在数据模型、数据库和功能上做出妥协。而有些过于简化的软件包其实存在了安全隐患。

---

**FastAPI** 不向任何数据库、数据模型或工具做妥协。

开发者可以灵活选择最适合项目的安全机制。

还可以直接使用 `passlib` 和 `PyJWT` 等维护良好、使用广泛的包，这是因为 **FastAPI** 不需要任何复杂机制，就能集成外部的包。

而且，**FastAPI** 还提供了一些工具，在不影响灵活、稳定和安全的前提下，尽可能地简化安全机制。

* 可选的 `client_id`（本例未使用）
* 可选的 `client_secret`（本例未使用）

/// info | 说明

`OAuth2PasswordRequestForm` 与 `OAuth2PasswordBearer` 一样，都不是 FastAPI 的特殊类。

**FastAPI** 把 `OAuth2PasswordBearer` 识别为安全方案。因此，可以通过这种方式把它添加至 OpenAPI。

但 `OAuth2PasswordRequestForm` 只是可以自行编写的类依赖项，也可以直接声明 `Form` 参数。

但由于这种用例很常见，FastAPI 为了简便，就直接提供了对它的支持。

///

### 使用表单数据

/// tip | 提示

from fastapi import FastAPI
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Image(BaseModel):
    url: HttpUrl
    name: str


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()
    images: list[Image] | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

from dataclasses import dataclass, field

from fastapi import FastAPI


@dataclass
class Item:
    name: str
    price: float
    tags: list[str] = field(default_factory=list)
    description: str | None = None
    tax: float | None = None


app = FastAPI()


@app.get("/items/next", response_model=Item)
async def read_next_item():
    return {
        "name": "Island In The Moon",
        "price": 12.99,

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


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

    model_config = {
        "json_schema_extra": {
            "examples": [
                {
                    "name": "Foo",
                    "description": "A very nice Item",

    value_is_sequence,
)
from fastapi.background import BackgroundTasks
from fastapi.concurrency import (
    asynccontextmanager,
    contextmanager_in_threadpool,
)
from fastapi.dependencies.models import Dependant
from fastapi.exceptions import DependencyScopeError
from fastapi.logger import logger
from fastapi.security.oauth2 import SecurityScopes
from fastapi.types import DependencyCacheKey

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32