👉 🙅 (🚫 📶 ⚠), ✋️ 🔜 ℹ 👥 🎯 🔛 ❔ 🎧-🔗 👷.

## 🥈 🔗, "☑" & "⚓️"

⤴️ 👆 💪 ✍ ➕1️⃣ 🔗 🔢 ("☑") 👈 🎏 🕰 📣 🔗 🚮 👍 (⚫️ "⚓️" 💁‍♂️):

//// tab | 🐍 3️⃣.6️⃣ & 🔛

```Python hl_lines="13"
{!> ../../docs_src/dependencies/tutorial005.py!}
```

////

//// tab | 🐍 3️⃣.1️⃣0️⃣ & 🔛

```Python hl_lines="11"
{!> ../../docs_src/dependencies/tutorial005_py310.py!}
```

////

        // 9
        "id:".encodeUtf8(),
        // 10
        "id\r\n".encodeUtf8(),
        // 11
        "id\r".encodeUtf8(),
        // 12
        "id\n".encodeUtf8(),
        // 13
        "event: ".encodeUtf8(),
        // 14
        "event:".encodeUtf8(),
        // 15
        "event\r\n".encodeUtf8(),
        // 16
        "event\r".encodeUtf8(),
        // 17

	{"fofofofofoofofoffofoobarfoo", "foffof", 13},
	{"fofofofofofofoffofoobarfoo", "foffofo", 12},
	{"fofofofofoofofoffofoobarfoo", "foffofo", 13},
	{"fofofofofoofofoffofoobarfoo", "foffofoo", 13},
	{"fofofofofofofoffofoobarfoo", "foffofoo", 12},
	{"fofofofofoofofoffofoobarfoo", "foffofoob", 13},
	{"fofofofofofofoffofoobarfoo", "foffofoob", 12},
	{"fofofofofoofofoffofoobarfoo", "foffofooba", 13},

	BFXILW $3, R27, $23, R14                   // 6e670333
	BFXIL $26, R8, $16, R20                    // 14a55ab3
	BICW R7@>15, R5, R16                       // b03ce70a
	BIC R12@>13, R12, R19                      // 9335ec8a
	BICSW R25->20, R3, R20                     // 7450b96a
	BICS R19->12, R1, R23                      // 3730b3ea
	BICS R19, R1, R23                          // 370033ea

        (byte)13, (byte) 5, (byte)60, (byte)52, (byte)44, (byte)36, (byte)28,
        (byte)20, (byte)12, (byte) 4, (byte)27, (byte)19, (byte)11, (byte)3
    };
    private static int[] totrot = {
        1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28
    };

    private static byte[] pc2 = {
        (byte)13, (byte)16, (byte)10, (byte)23, (byte) 0, (byte) 4,

		success    bool
	}{
		// Invalid inputs.
		{
			[]string{"data{1...17}/export{1...52}"},
			[]uint64{14144},
			nil,
			false,
		},
		// Valid inputs.
		{
			[]string{"data{1...3}"},
			[]uint64{3},
			[][]uint64{{3}},
			true,
		},
		{
			[]string{"data/controller1/export{1...2}, data/controller2/export{1...4}, data/controller3/export{1...8}"},
			[]uint64{2, 4, 8},

        assertEquals("   j", s315, "11");
        String s314 = props1.getProperty("space");
        assertEquals("   c", s314, "12");
        String s313 = props1.getProperty("dblbackslash");
        assertEquals("\\", s313, "13");

        String s312 = props2.getProperty(" \r");
        assertEquals("\n \t \f", s312, "1");
        String s311 = props2.getProperty("a");
        assertEquals("a", s311, "2");

	}
	// as per the doc, only 11 fields are guaranteed
	// only set if available
	if len(stats) > 14 {
		iostats.DiscardIOs = stats[11]
		iostats.DiscardMerges = stats[12]
		iostats.DiscardSectors = stats[13]
		iostats.DiscardTicks = stats[14]
	}
	return
}

func readStat(fileName string) (stats []uint64, err error) {
	file, err := os.Open(fileName)
	if err != nil {
		return nil, err
	}

                TestCoverage(12, TestType.noDaemon, Os.LINUX, JvmCategory.MIN_VERSION, DEFAULT_LINUX_FUNCTIONAL_TEST_BUCKET_SIZE),
                TestCoverage(13, TestType.noDaemon, Os.WINDOWS, JvmCategory.MAX_LTS_VERSION),
                TestCoverage(14, TestType.platform, Os.MACOS, JvmCategory.MIN_VERSION_WINDOWS_MAC, expectedBucketNumber = 5, arch = Arch.AMD64),

{!../../docs_src/dependencies/tutorial005.py!}
```

这段代码声明了类型为 `str` 的可选查询参数 `q`，然后返回这个查询参数。

这个函数很简单（不过也没什么用），但却有助于让我们专注于了解子依赖项的工作方式。

### 第二层依赖项

接下来，创建另一个依赖项函数，并同时用该依赖项自身再声明一个依赖项（所以这也是一个「依赖项」）：

```Python hl_lines="13"
{!../../docs_src/dependencies/tutorial005.py!}
```

这里重点说明一下声明的参数：

* 尽管该函数自身是依赖项，但还声明了另一个依赖项（它「依赖」于其他对象）
    * 该函数依赖 `query_extractor`, 并把 `query_extractor` 的返回值赋给参数 `q`