<img src="/img/python-types/image05.png">

Đa phần đều không thể đạt được nếu không có các kiểu dữ liệu.

Chú ý rằng, biến `item` là một trong các phần tử trong danh sách `items`.

Và do vậy, trình soạn thảo biết nó là một `str`, và cung cấp sự hỗ trợ cho nó.

#### Tuple and Set

Bạn sẽ làm điều tương tự để khai báo các `tuple` và  các `set`:

///

```mermaid
graph TB

query_extractor(["query_extractor"])
query_or_cookie_extractor(["query_or_cookie_extractor"])

read_query["/items/"]

query_extractor --> query_or_cookie_extractor --> read_query
```

## 同じ依存関係の複数回の使用

依存関係の１つが同じ*path operation*に対して複数回宣言されている場合、例えば、複数の依存関係が共通のサブ依存関係を持っている場合、**FastAPI** はリクエストごとに１回だけそのサブ依存関係を呼び出します。

================ test session starts ================
platform linux -- Python 3.6.9, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
rootdir: /home/user/code/superawesome-cli/app
plugins: forked-1.1.3, xdist-1.31.0, cov-2.8.1
collected 6 items

---> 100%

test_main.py <span style="color: green; white-space: pre;">......                            [100%]</span>

<span style="color: green;">================= 1 passed in 0.03s =================</span>

================ test session starts ================
platform linux -- Python 3.6.9, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
rootdir: /home/user/code/superawesome-cli/app
plugins: forked-1.1.3, xdist-1.31.0, cov-2.8.1
collected 6 items

---> 100%

test_main.py <span style="color: green; white-space: pre;">......                            [100%]</span>

<span style="color: green;">================= 1 passed in 0.03s =================</span>

{* ../../docs_src/events/tutorial001.py hl[8] *}

In diesem Fall initialisiert die Eventhandler-Funktion `startup` die „Datenbank“ der Items (nur ein `dict`) mit einigen Werten.

Sie können mehr als eine Eventhandler-Funktion hinzufügen.

Und Ihre Anwendung empfängt erst dann Anfragen, wenn alle `startup`-Eventhandler abgeschlossen sind.

         * @param server the Tomcat server instance
         * @param connector the Tomcat connector
         * @param props the configuration properties
         * @param readConfigList the list of read configuration items
         */
        @Override
        public void setupServerConfigIfNeeds(final BootLogger logger, final Tomcat server, final Connector connector,
                final Properties props, final List<String> readConfigList) {

                                                   styleClass="form-control">
                                            <c:forEach var="l" varStatus="s" items="${labelTypeItems}">
                                                <la:option value="${f:u(l.id)}">${f:h(l.name)}</la:option>
                                            </c:forEach>

  }

  public void testConsumingIterable_queue_iterator() {
    List<Integer> items = ImmutableList.of(4, 8, 15, 16, 23, 42);
    new IteratorTester<Integer>(3, UNMODIFIABLE, items, IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterables.consumingIterable(new LinkedList<>(items)).iterator();
      }
    }.test();
  }

        default:
            break;
        }
        return OptionalEntity.empty();
    }

    /**
     * Create a char mapping item.
     * @param form The create form.
     * @param hook The error hook.
     * @return An optional entity of a char mapping item.
     */
    protected OptionalEntity<CharMappingItem> createCharMappingItem(final CreateForm form, final VaErrorHook hook) {
        try {

                                                   styleClass="form-control">
                                            <c:forEach var="l" varStatus="s" items="${labelTypeItems}">
                                                <la:option value="${f:u(l.id)}">${f:h(l.name)}</la:option>
                                            </c:forEach>