下一章介绍详细内容。

## 顺序很重要

有时，*路径操作*中的路径是写死的。

比如要使用 `/users/me` 获取当前用户的数据。

然后还要使用 `/users/{user_id}`，通过用户 ID 获取指定用户的数据。

由于*路径操作*是按顺序依次运行的，因此，一定要在 `/users/{user_id}` 之前声明 `/users/me` ：

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003.py!}
```

否则，`/users/{user_id}` 将匹配 `/users/me`，FastAPI 会**认为**正在接收值为 `"me"` 的 `user_id` 参数。

## 预设值

from fastapi import Depends, FastAPI
from fastapi.security import HTTPBasic, HTTPBasicCredentials
from typing_extensions import Annotated

app = FastAPI()

security = HTTPBasic()


@app.get("/users/me")
def read_current_user(credentials: Annotated[HTTPBasicCredentials, Depends(security)]):

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package gradlebuild

import me.champeau.gradle.japicmp.report.GroovyReportRenderer
import me.champeau.gradle.japicmp.JApiCmpWorkerAction
import me.champeau.gradle.japicmp.report.RichReportData

class EnrichedReportRenderer extends GroovyReportRenderer {

        By asking questions in a structured way (following this) it will be much easier to help you.

        And there's a high chance that you will find the solution along the way and you won't even have to submit it and wait for an answer. 😎

        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")
async def read_users_me(current_user: User = Depends(get_current_active_user)):

        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):

        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):

💖 `/users/me`, ➡️ 💬 👈 ⚫️ 🤚 📊 🔃 ⏮️ 👩‍💻.

& ⤴️ 👆 💪 ✔️ ➡ `/users/{user_id}` 🤚 💽 🔃 🎯 👩‍💻 👩‍💻 🆔.

↩️ *➡ 🛠️* 🔬 ✔, 👆 💪 ⚒ 💭 👈 ➡ `/users/me` 📣 ⏭ 1️⃣ `/users/{user_id}`:

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003.py!}
```

⏪, ➡ `/users/{user_id}` 🔜 🏏 `/users/me`, "💭" 👈 ⚫️ 📨 🔢 `user_id` ⏮️ 💲 `"me"`.

➡, 👆 🚫🔜 ↔ ➡ 🛠️:

import gradlebuild.binarycompatibility.upgrades.UpgradedProperty.ReplacedAccessor;
import gradlebuild.binarycompatibility.upgrades.UpgradedProperty.AccessorKey;
import me.champeau.gradle.japicmp.report.PostProcessViolationsRule;
import me.champeau.gradle.japicmp.report.ViolationCheckContextWithViolations;
import org.gradle.util.internal.CollectionUtils;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

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

app = FastAPI()

security = HTTPBasic()


@app.get("/users/me")
def read_current_user(credentials: HTTPBasicCredentials = Depends(security)):