import secrets

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

app = FastAPI()

security = HTTPBasic()


def get_current_username(credentials: HTTPBasicCredentials = Depends(security)):
    current_username_bytes = credentials.username.encode("utf8")
    correct_username_bytes = b"stanleyjobson"
    is_correct_username = secrets.compare_digest(

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 datetime import datetime, timedelta, timezone
from typing import Annotated

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:

///

### 匯入 `Depends` { #import-depends }

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[3] *}

### 在「被依賴者」（dependant）中宣告依賴 { #declare-the-dependency-in-the-dependant }

和你在「路徑操作函式」參數上使用 `Body`、`Query` 等方式一樣，針對新參數使用 `Depends`：

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

雖然你在函式參數上使用 `Depends` 的方式和 `Body`、`Query` 等相同，但 `Depends` 的運作方式有點不同。

你只需要傳給 `Depends` 一個參數。

# Ref: https://github.com/fastapi/fastapi/issues/14271
from fastapi import Depends, FastAPI
from fastapi.security import HTTPBearer
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

app = FastAPI()

bearer_scheme = HTTPBearer()


@app.get("/", dependencies=[Depends(bearer_scheme)])
async def get_root():
    return {"message": "Hello, World!"}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.

from fastapi import Depends, FastAPI, Security
from fastapi.security import APIKeyHeader
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyHeader(name="key")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user

///

### 导入 `Depends` { #import-depends }

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[3] *}

### 在“dependant”中声明依赖项 { #declare-the-dependency-in-the-dependant }

与在*路径操作函数*的参数中使用 `Body`、`Query` 等相同，给参数使用 `Depends` 来声明一个新的依赖项：

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

虽然你在函数参数中使用 `Depends` 的方式与 `Body`、`Query` 等相同，但 `Depends` 的工作方式略有不同。

这里只能给 `Depends` 传入一个参数。

/// info | Technical Details

`Security` is actually a subclass of `Depends`, and it has just one extra parameter that we'll see later.

But by using `Security` instead of `Depends`, **FastAPI** will know that it can declare security scopes, use them internally, and document the API with OpenAPI.

But when you import `Query`, `Path`, `Depends`, `Security` and others from `fastapi`, those are actually functions that return special classes.

from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

app = FastAPI()


async def user_exists(user_id: int):
    return True


@app.get("/users/{user_id}", dependencies=[Depends(user_exists)])
async def read_users(user_id: int):
    pass


client = TestClient(app)


def test_read_users():
    response = client.get("/users/42")