{!../../../docs_src/python_types/tutorial009c.py!}
```

🔢 `name` 🔬 `Optional[str]`, ✋️ ⚫️ **🚫 📦**, 👆 🚫🔜 🤙 🔢 🍵 🔢:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

`name` 🔢 **✔** (🚫 *📦*) ↩️ ⚫️ 🚫 ✔️ 🔢 💲. , `name` 🚫 `None` 💲:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

👍 📰, 🕐 👆 🔛 🐍 3️⃣.1️⃣0️⃣ 👆 🏆 🚫 ✔️ 😟 🔃 👈, 👆 🔜 💪 🎯 ⚙️ `|` 🔬 🇪🇺 🆎:

ckb_IQ=ckb-iq\n\
cs=cs\n\
da=da\n\
de=de\n\
el=el\n\
en=en\n\
en-ie=en-ie\n\
en_IE=en-ie\n\
es=es\n\
et=et\n\
eu=eu\n\
fa=fa\n\
fi=fi\n\
fr=fr\n\
gl=gl\n\
gu=gu\n\
he=he\n\
hi=hi\n\
hr=hr\n\
hu=hu\n\
hy=hy\n\
id=id\n\
it=it\n\
ja=ja\n\
ko=ko\n\
lt=lt\n\
lv=lv\n\
mk=mk\n\
ml=ml\n\
nl=nl\n\
no=no\n\
pa=pa\n\
pl=pl\n\
pt=pt\n\
pt-br=pt-br\n\

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

Tham số `name` **vẫn được yêu cầu** (không phải là *tùy chọn*) vì nó không có giá trị mặc định. Trong khi đó, `name` chấp nhận `None` như là giá trị:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

```Python
say_hi()  # ওহ না, এটি একটি ত্রুটি নিক্ষেপ করবে! 😱
```

`name` প্যারামিটারটি **এখনও আবশ্যিক** (নন-অপশনাল) কারণ এটির কোনো ডিফল্ট মান নেই। তবুও, `name` এর মান হিসেবে `None` গ্রহণযোগ্য:

```Python
say_hi(name=None)  # এটি কাজ করে, None বৈধ 🎉
```

	}
	fmt.Printf("%s\n", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
	// Output:
	// 'Gjnf oevyyvt naq gur fyvgul tbcure...
}

func ExampleReader_Len() {
	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
	// Output:
	// 3
	// 16
}

func ExampleRepeat() {
	fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
	// Output: banana
}

				Format:  FormatGNU,
			}, nil},
			testClose{nil},
		},
	}, {
		file: "testdata/gnu-not-utf8.tar",
		tests: []testFnc{
			testHeader{Header{
				Typeflag: TypeReg,
				Name:     "hi\x80\x81\x82\x83bye",
				Mode:     0644,
				Uid:      1000,
				Gid:      1000,
				Uname:    "rawr",
				Gname:    "dsnet",
				ModTime:  time.Unix(0, 0),
				Format:   FormatGNU,
			}, nil},

     * en_IE=en-ie<br>
     * es=es<br>
     * et=et<br>
     * eu=eu<br>
     * fa=fa<br>
     * fi=fi<br>
     * fr=fr<br>
     * gl=gl<br>
     * gu=gu<br>
     * he=he<br>
     * hi=hi<br>
     * hr=hr<br>
     * hu=hu<br>
     * hy=hy<br>
     * id=id<br>
     * it=it<br>
     * ja=ja<br>
     * ko=ko<br>
     * lt=lt<br>
     * lv=lv<br>
     * mk=mk<br>

    ListenableFuture<?>[] futures = new ListenableFuture<?>[0];
    Callable<String> combiner =
        new Callable<String>() {
          @Override
          public String call() throws Exception {
            return "hi";
          }
        };

    // We'd like for all the following to compile.
    ListenableFuture<String> unused;

    // Compiles:

const h = "foo" > "bar"    // h == true  (untyped boolean constant)
const j = true             // j == true  (untyped boolean constant)
const k = 'w' + 1          // k == 'x'   (untyped rune constant)
const l = "hi"             // l == "hi"  (untyped string constant)
const m = string(k)        // m == "x"   (type string)
const Σ = 1 - 0.707i       //            (untyped complex constant)