*
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <p>Historically, {@code Predicate} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Predicate} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override

log.txt
Pipfile.lock
env3.*
env
docs_build
site_build
venv
docs.zip
archive.zip

# vim temporary files
*~
.*.sw?
.cache

# macOS
.DS_Store

# Ignore while the setup still depends on requirements.txt files
uv.lock

もしくは、依存関係が値を返さない場合もあります。

しかし、それでも実行・解決する必要があります。

このような場合、*path operation関数*のパラメータを`Depends`で宣言する代わりに、*path operation decorator*に`dependencies`の`list`を追加することができます。

##  *path operationデコレータ*への`dependencies`の追加

*path operationデコレータ*はオプショナルの引数`dependencies`を受け取ります。

それは`Depends()`の`list`であるべきです:

{* ../../docs_src/dependencies/tutorial006.py hl[17] *}

    public static final String MAKE_MODE = "make";

    public static final String MAKE_DEPENDENTS_MODE = "make-dependents";

    // make projects that depend on me, and projects that I depend on
    public static final String MAKE_BOTH_MODE = "make-both";

    private List<String> blackList = new ArrayList<>();

    private Map<String, BuildFailure> buildFailuresByProject = new HashMap<>();

			// that broke people during the Go 1.8 testing
			// period. People depend on it being 0 I
			// guess. Maybe retry later. See Issue 18117.
		}
		// For client requests, Request.ContentLength of 0
		// means either actually 0, or unknown. The only way
		// to explicitly say that the ContentLength is zero is
		// to set the Body to nil. But turns out too much code
		// depends on NewRequest returning a non-nil Body,

# o url      -- The URL for connecting database.
# o schema   -- The schema name.
# o user     -- The database user name.
# o password -- The database password.
# o propertiesMap -- The properties that depends on the database.
# o variousMap    -- The various settings about JDBC task.
#
# *The line that starts with '#' means comment-out.
#
map:{
    ; driver   = org.h2.Driver

在高级使用场景中，如果不想使用「缓存」值，而是为需要在同一请求的每一步操作（多次）中都实际调用依赖项，可以把 `Depends` 的参数 `use_cache` 的值设置为 `False` :

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

## 小结

千万别被本章里这些花里胡哨的词藻吓倒了，其实**依赖注入**系统非常简单。

依赖注入无非是与*路径操作函数*一样的函数罢了。

    ## Example

    ```python
    from typing import Annotated

    from fastapi import Depends, FastAPI
    from fastapi.security import OAuth2PasswordRequestForm

    app = FastAPI()


    @app.post("/login")
    def login(form_data: Annotated[OAuth2PasswordRequestForm, Depends()]):
        data = {}
        data["scopes"] = []
        for scope in form_data.scopes:

# Security Tools

When you need to declare dependencies with OAuth2 scopes you use `Security()`.

But you still need to define what is the dependable, the callable that you pass as a parameter to `Depends()` or `Security()`.

There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.

Pero si por alguna razón tus clientes dependen del comportamiento anterior, puedes volver a él sobrescribiendo el método `make_not_authenticated_error` en tus clases de seguridad.