from datetime import datetime
from typing import Annotated

from fastapi import FastAPI, Security
from fastapi.security import HTTPBearer
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

bearer_scheme = HTTPBearer()


class Subscription(BaseModel):
    username: str
    monthly_fee: float
    start_date: datetime


@app.webhooks.post("new-subscription")
def new_subscription(

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("We don't swallow the internal error here, we raise again 😎")
        raise


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):

from typing import Annotated

from fastapi import Depends, FastAPI, Header, HTTPException


async def verify_token(x_token: Annotated[str, Header()]):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def verify_key(x_key: Annotated[str, Header()]):
    if x_key != "fake-super-secret-key":
        raise HTTPException(status_code=400, detail="X-Key header invalid")

It would be roughly equivalent to typing:

<div class="termy">

```console
$ /opt/custompython/bin/python
```

</div>

////

//// tab | Windows

The system will **find** the `python` program in `C:\opt\custompython\bin\python` and run it.

It would be roughly equivalent to typing:

<div class="termy">

```console

import secrets
from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import HTTPBasic, HTTPBasicCredentials

app = FastAPI()

security = HTTPBasic()


def get_current_username(
    credentials: Annotated[HTTPBasicCredentials, Depends(security)],
):
    current_username_bytes = credentials.username.encode("utf8")
    correct_username_bytes = b"stanleyjobson"

from typing import Annotated, Optional

from fastapi import FastAPI, File, Form
from starlette.testclient import TestClient

app = FastAPI()


@app.post("/urlencoded")
async def post_url_encoded(age: Annotated[Optional[int], Form()] = None):
    return age


@app.post("/multipart")
async def post_multi_part(
    age: Annotated[Optional[int], Form()] = None,
    file: Annotated[Optional[bytes], File()] = None,
):

from typing import Union

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


class HeroBase(SQLModel):
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)


class Hero(HeroBase, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    secret_name: str


class HeroPublic(HeroBase):

from typing import Annotated, Union

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

app = FastAPI()


class UserForm(BaseModel):
    name: str
    email: str


class CompanyForm(BaseModel):
    company_name: str
    industry: str


@app.post("/form-union/")
def post_union_form(data: Annotated[Union[UserForm, CompanyForm], Form()]):

## 具有子类型的 List 字段

但是 Python 有一种特定的方法来声明具有子类型的列表：

### 从 typing 导入 `List`

首先，从 Python 的标准库 `typing` 模块中导入 `List`：

{* ../../docs_src/body_nested_models/tutorial002.py hl[1] *}

### 声明具有子类型的 List

要声明具有子类型的类型，例如 `list`、`dict`、`tuple`：

* 从 `typing` 模块导入它们
* 使用方括号 `[` 和 `]` 将子类型作为「类型参数」传入

```Python
from typing import List

my_list: List[str]
```

这完全是用于类型声明的标准 Python 语法。

import gzip
from typing import Annotated, Callable

from fastapi import Body, FastAPI, Request, Response
from fastapi.routing import APIRoute


class GzipRequest(Request):
    async def body(self) -> bytes:
        if not hasattr(self, "_body"):
            body = await super().body()
            if "gzip" in self.headers.getlist("Content-Encoding"):
                body = gzip.decompress(body)
            self._body = body