def test_no_token():
    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token():
    access_token = get_access_token(scope="me")
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}
    )

    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


@needs_py39
def test_token(client: TestClient):
    access_token = get_access_token(scope="me", client=client)
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}

You can connect with <a href="https://tiangolo.com" class="external-link" target="_blank">me (Sebastián Ramírez / `tiangolo`)</a>, the author.

You can:

* <a href="https://github.com/tiangolo" class="external-link" target="_blank">Follow me on **GitHub**</a>.
    * See other Open Source projects I have created that could help you.
    * Follow me to see when I create a new Open Source project.

<img src="/img/tutorial/security/image11.png">

🚥 👆 🚫 🖊 🙆 ↔, 👆 🔜 "🔓", ✋️ 🕐❔ 👆 🔄 🔐 `/users/me/` ⚖️ `/users/me/items/` 👆 🔜 🤚 ❌ 💬 👈 👆 🚫 ✔️ 🥃 ✔. 👆 🔜 💪 🔐 `/status/`.

&amp; 🚥 👆 🖊 ↔ `me` ✋️ 🚫 ↔ `items`, 👆 🔜 💪 🔐 `/users/me/` ✋️ 🚫 `/users/me/items/`.

👈 ⚫️❔ 🔜 🔨 🥉 🥳 🈸 👈 🔄 🔐 1️⃣ 👫 *➡ 🛠️* ⏮️ 🤝 🚚 👩‍💻, ⚓️ 🔛 ❔ 📚 ✔ 👩‍💻 🤝 🈸.

## 🔃 🥉 🥳 🛠️

它们会为每个*路径操作*进行单独检查。

## 查看文档

打开 API 文档，进行身份验证，并指定要授权的作用域。

<img src="/img/tutorial/security/image11.png">

没有选择任何作用域，也可以进行**身份验证**，但访问 `/uses/me` 或 `/users/me/items` 时，会显示没有足够的权限。但仍可以访问 `/status/`。

如果选择了作用域 `me`，但没有选择作用域 `items`，则可以访问 `/users/me/`，但不能访问 `/users/me/items`。

这就是通过用户提供的令牌使用第三方应用访问这些*路径操作*时会发生的情况，具体怎样取决于用户授予第三方应用的权限。

## 关于第三方集成

本例使用 OAuth2 **密码**流。

这种方式适用于登录我们自己的应用，最好使用我们自己的前端。

    return form_data


@app.get("/users/me")
def read_users_me(current_user: Optional[User] = Depends(get_current_user)):
    if current_user is None:
        return {"msg": "Create an account first"}
    return current_user


client = TestClient(app)


def test_security_oauth2():
    response = client.get("/users/me", headers={"Authorization": "Bearer footokenbar"})

def test_no_token():
    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token():
    access_token = get_access_token(scope="me")
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}
    )

    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


@needs_py310
def test_token(client: TestClient):
    access_token = get_access_token(scope="me", client=client)
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}

    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


@needs_py39
def test_token(client: TestClient):
    access_token = get_access_token(scope="me", client=client)
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}

    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


@needs_py310
def test_token(client: TestClient):
    access_token = get_access_token(scope="me", client=client)
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}