* Les clés de ce dictionnaire sont de type `str`.
    * Les valeurs de ce dictionnaire sont de type `float`.

#### `Optional`

Vous pouvez aussi utiliser `Optional` pour déclarer qu'une variable a un type, comme `str` mais qu'il est "optionnel" signifiant qu'il pourrait aussi être `None`.

{*../../docs_src/python_types/tutorial009.py hl[1,4] *}

func (p *Parser) positiveAtoi(str string) int64 {
	value, err := strconv.ParseInt(str, 0, 64)
	if err != nil {
		p.errorf("%s", err)
	}
	if value < 0 {
		p.errorf("%s overflows int64", str)
	}
	return value
}

func (p *Parser) atoi(str string) uint64 {
	value, err := strconv.ParseUint(str, 0, 64)
	if err != nil {
		p.errorf("%s", err)
	}

	// Bucket to list
	bucketToList string

	// Session policy file (FIXME: add support in minio-go)
	sessionPolicyFile string
)

func init() {
	flag.StringVar(&stsEndpoint, "sts-ep", "http://localhost:9000", "STS endpoint")
	flag.StringVar(&minioUsername, "u", "", "MinIO Username")
	flag.StringVar(&minioPassword, "p", "", "MinIO Password")
	flag.BoolVar(&displayCreds, "d", false, "Only show generated credentials")

     * Parses a DCERPC binding string into a DcerpcBinding object
     * @param str the binding string to parse
     * @return the parsed DcerpcBinding object
     * @throws DcerpcException if the binding string is malformed
     */
    protected static DcerpcBinding parseBinding(final String str) throws DcerpcException {
        int state, mark, si;
        final char[] arr = str.toCharArray();
        String proto = null, key = null;

      checkPositionIndexes(off, off + len, cbuf.length);
    }

    @Override
    public void write(String str) {
      checkNotNull(str);
    }

    @Override
    public void write(String str, int off, int len) {
      checkPositionIndexes(off, off + len, str.length());
    }

    @Override
    public Writer append(@Nullable CharSequence csq) {
      return this;
    }

////

👯‍♂️ 💼 👉 ⛓ 👈 `item` 💪 `int` ⚖️ `str`.

#### 🎲 `None`

👆 💪 📣 👈 💲 💪 ✔️ 🆎, 💖 `str`, ✋️ 👈 ⚫️ 💪 `None`.

🐍 3️⃣.6️⃣ & 🔛 (✅ 🐍 3️⃣.1️⃣0️⃣) 👆 💪 📣 ⚫️ 🏭 & ⚙️ `Optional` ⚪️➡️ `typing` 🕹.

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

⚙️ `Optional[str]` ↩️ `str` 🔜 ➡️ 👨‍🎨 ℹ 👆 🔍 ❌ 🌐❔ 👆 💪 🤔 👈 💲 🕧 `str`, 🕐❔ ⚫️ 💪 🤙 `None` 💁‍♂️.

   * Converts the specified {@code String str} from this format to the specified {@code format}. A
   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);

	Expiry      int    `json:"expires_in"`
}

var (
	stsEndpoint  string
	idpEndpoint  string
	clientID     string
	clientSecret string
)

func init() {
	flag.StringVar(&stsEndpoint, "sts-ep", "http://localhost:9000", "STS endpoint")
	flag.StringVar(&idpEndpoint, "idp-ep", "http://localhost:8080/auth/realms/minio/protocol/openid-connect/token", "IDP token endpoint")
	flag.StringVar(&clientID, "cid", "", "Client ID")

     * Encodes a wide string pointer in NDR format.
     *
     * @param buf the NDR buffer
     * @param str the string to encode (can be null)
     * @throws NdrException if encoding fails
     */
    private void encodeWideStringPointer(NdrBuffer buf, String str) throws NdrException {
        if (str == null || str.isEmpty()) {
            buf.enc_ndr_long(0); // NULL pointer
        } else {

In diesem Beispiel wird das Pydantic-Modell in ein `dict`, und das `datetime`-Objekt in ein `str` konvertiert.

Das Resultat dieses Aufrufs ist etwas, das mit Pythons Standard-<a href="https://docs.python.org/3/library/json.html#json.dumps" class="external-link" target="_blank">`json.dumps()`</a> kodiert werden kann.