Und wiederum benötigt `dependency_b` den Wert von `dependency_a` (hier `dep_a` genannt) für seinen Exit-Code.

=== "Python 3.9+"

    ```Python hl_lines="18-19  26-27"
    {!> ../../../docs_src/dependencies/tutorial008_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="17-18  25-26"
    {!> ../../../docs_src/dependencies/tutorial008_an.py!}
    ```

And, in turn, `dependency_b` needs the value from `dependency_a` (here named `dep_a`) to be available for its exit code.

=== "Python 3.9+"

    ```Python hl_lines="18-19  26-27"
    {!> ../../../docs_src/dependencies/tutorial008_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="17-18  25-26"
    {!> ../../../docs_src/dependencies/tutorial008_an.py!}
    ```

И, в свою очередь, `dependency_b` нуждается в том, чтобы значение из `dependency_a` (здесь `dep_a`) было доступно для ее завершающего кода.

=== "Python 3.9+"

    ```Python hl_lines="18-19  26-27"
    {!> ../../../docs_src/dependencies/tutorial008_an_py39.py!}
    ```

=== "Python 3.6+"

    ```Python hl_lines="17-18  25-26"
    {!> ../../../docs_src/dependencies/tutorial008_an.py!}
    ```

所有这些依赖都可以使用`yield`。

在这种情况下，`dependency_c` 在执行其退出代码时需要`dependency_b`（此处称为 `dep_b`）的值仍然可用。

而`dependency_b` 反过来则需要`dependency_a`（此处称为 `dep_a`）的值在其退出代码中可用。

=== "Python 3.9+"

    ```Python hl_lines="18-19  26-27"
    {!> ../../../docs_src/dependencies/tutorial008_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="17-18  25-26"
    {!> ../../../docs_src/dependencies/tutorial008_an.py!}
    ```