This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant" { #second-dependency-dependable-and-dependant }

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

    * Required scopes `["items"]` with the dependency:
    * `get_current_active_user`:
        *  The dependency function `get_current_active_user` has:
            * Required scopes `["me"]` with the dependency:
            * `get_current_user`:
                * The dependency function `get_current_user` has:
                    * No scopes required by itself.
                    * A dependency using `oauth2_scheme`.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }

Ele sempre terá os escopos de segurança declarados nas dependências atuais de `Security` e todos os dependentes para **aquela** *operação de rota* **específica** e **aquela** árvore de dependência **específica**.

* `fastapi-cli` - untuk menyediakan perintah `fastapi`.

### Tanpda dependensi `standard`

Jika anda tidak ingin menambahkan dependensi opsional `standard`, anda dapat menggunakan `pip install fastapi` daripada `pip install "fastapi[standard]"`.

### Dependensi Opsional Tambahan

		</dependency>
		<dependency>
			<groupId>org.apache.logging.log4j</groupId>
			<artifactId>log4j-api</artifactId>
			<version>${log4j.version}</version>
		</dependency>
		<dependency>
			<groupId>org.apache.logging.log4j</groupId>
			<artifactId>log4j-core</artifactId>
			<version>${log4j.version}</version>
		</dependency>
		<dependency>
			<groupId>org.apache.logging.log4j</groupId>

We can do better...

## What makes a dependency { #what-makes-a-dependency }

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

The key factor is that a dependency should be a "callable".

A "**callable**" in Python is anything that Python can "call" like a function.

    </dependency>
    <dependency>
      <groupId>org.jline</groupId>
      <artifactId>jline-terminal-jni</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jline</groupId>
      <artifactId>jline-terminal-ffm</artifactId>
    </dependency>

    <!-- (legacy) DI annotations -->
    <dependency>
      <groupId>javax.inject</groupId>
      <artifactId>javax.inject</artifactId>
    </dependency>

///

## Dependencies errors and return values { #dependencies-errors-and-return-values }

You can use the same dependency *functions* you use normally.

### Dependency requirements { #dependency-requirements }

They can declare request requirements (like headers) or other sub-dependencies:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

			<version>1.7.36</version>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-reload4j</artifactId>
			<version>1.7.36</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.bouncycastle</groupId>
			<artifactId>bcprov-jdk18on</artifactId>
			<version>1.80</version>
		</dependency>
		<dependency>
			<groupId>org.junit.jupiter</groupId>