{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

Although you use `Depends` in the parameters of your function the same way you use `Body`, `Query`, etc, `Depends` works a bit differently.

You only give `Depends` a single parameter.

This parameter must be something like a function.

You **don't call it** directly (don't add the parenthesis at the end), you just pass it as a parameter to `Depends()`.

{* ../../docs_src/path_params/tutorial002_py39.py hl[7] *}

In this case, `item_id` is declared to be an `int`.

/// check

This will give you editor support inside of your function, with error checks, completion, etc.

///

## Data <abbr title="also known as: serialization, parsing, marshalling">conversion</abbr> { #data-conversion }

# 第一步

最簡單的 FastAPI 檔案可能看起來像這樣：

{* ../../docs_src/first_steps/tutorial001.py *}

將其複製到一個名為 `main.py` 的文件中。

執行即時重新載入伺服器（live server）：

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

# ----------------------------------------------------------
# Application Exception
# ---------------------
# /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# five framework-embedded messages (don't change key names)
# - - - - - - - - - -/
errors.login.failure = Login gagal.
errors.app.illegal.transition = Transisi tidak valid. Silakan coba lagi.

				return true
			}
		}

		// Note: updates from healEntry to tracker must be sent on results channel.
		healEntry := func(bucket string, entry metaCacheEntry) {
			defer jt.Give()

			if entry.name == "" && len(entry.metadata) == 0 {
				// ignore entries that don't have metadata.
				return
			}
			if entry.isDir() {
				// ignore healing entry.name's with `/` suffix.
				return

                    } catch (InterruptedException e) {
                        // Ignore
                    }
                }
            });

            waiter.start();
            Thread.sleep(50); // Give waiter time to start

            response.received();

            assertTrue(latch.await(500, TimeUnit.MILLISECONDS));
            assertTrue(response.isReceived());
        }

        @Test

# ----------------------------------------------------------
# Application Exception
# ---------------------
# /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# five framework-embedded messages (don't change key names)
# - - - - - - - - - -/
errors.login.failure = Error de inicio de sesión.
errors.app.illegal.transition = Transición ilegal. Por favor, inténtelo de nuevo.

      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

   */
  public long sum() {
    return map.values().stream().mapToLong(Long::longValue).sum();
  }

  @LazyInit private transient @Nullable Map<K, Long> asMap;

  /** Returns a live, read-only view of the map backing this {@code AtomicLongMap}. */
  public Map<K, Long> asMap() {
    Map<K, Long> result = asMap;
    return (result == null) ? asMap = createAsMap() : result;
  }