def main(user_id: str):
    return user_id


# A Pydantic model
class User(BaseModel):
    id: int
    name: str
    joined: date
```

That can then be used like:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

/// info

// https://www.iana.org/domains/root/db/gallup.html
gallup

// game : XYZ.COM LLC
// https://www.iana.org/domains/root/db/game.html
game

// games : Dog Beach, LLC
// https://www.iana.org/domains/root/db/games.html
games

// gap : The Gap, Inc.
// https://www.iana.org/domains/root/db/gap.html
gap

// garden : Registry Services, LLC

# ----------------------------------------------------------
# Application Exception
# ---------------------
# /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# five framework-embedded messages (don't change key names)
# - - - - - - - - - -/
errors.login.failure = 登入失敗。
errors.app.illegal.transition = 非法轉換，請重試。
errors.app.db.already.deleted = 可能已被其他程序刪除。請重試。
errors.app.db.already.updated = 可能已被其他程序更新。請重試。

// and options for creating keys.
type CreateKeyRequest struct {
	// Name is the name of the key that gets created.
	Name string
}

// DeleteKeyRequest is a structure containing fields
// and options for deleting keys.
type DeleteKeyRequest struct {
	// Name is the name of the key that gets deleted.
	Name string
}

// GenerateKeyRequest is a structure containing fields

  private static final Splitter KEYS_SPLITTER = Splitter.on(',').trimResults();

  /** Splits the key from the value. */
  private static final Splitter KEY_VALUE_SPLITTER = Splitter.on('=').trimResults();

  /** Map of names to ValueParser. */
  private static final ImmutableMap<String, ValueParser> VALUE_PARSERS =
      ImmutableMap.<String, ValueParser>builder()
          .put("initialCapacity", new InitialCapacityParser())

  private static final Splitter KEYS_SPLITTER = Splitter.on(',').trimResults();

  /** Splits the key from the value. */
  private static final Splitter KEY_VALUE_SPLITTER = Splitter.on('=').trimResults();

  /** Map of names to ValueParser. */
  private static final ImmutableMap<String, ValueParser> VALUE_PARSERS =
      ImmutableMap.<String, ValueParser>builder()
          .put("initialCapacity", new InitialCapacityParser())

    /**
     * Constructs a SID from an RPC sid_t structure.
     *
     * @param sid the RPC sid_t structure
     * @param type the SID type
     * @param domainName the domain name for this SID
     * @param acctName the account name for this SID
     * @param decrementAuthority whether to decrement the authority count
     */

func (in *Input) define() {
	name := in.macroName()
	args, tokens := in.macroDefinition(name)
	in.defineMacro(name, args, tokens)
}

// defineMacro stores the macro definition in the Input.
func (in *Input) defineMacro(name string, args []string, tokens []Token) {
	if in.macros[name] != nil {
		in.Error("redefinition of macro:", name)
	}
	in.macros[name] = &Macro{
		name:   name,
		args:   args,
		tokens: tokens,

	config.Lock()
	defer config.Unlock()

	// check if tier name is in all caps
	tierName := tier.Name
	if tierName != strings.ToUpper(tierName) {
		return errTierNameNotUppercase
	}

	// check if tier name already in use
	if _, exists := config.isTierNameInUse(tierName); exists {
		return errTierAlreadyExists
	}

Nur ein technisches Detail für die neugierigen Nerds. 🤓

In der technischen ASGI-Spezifikation ist dies Teil des [Lifespan Protokolls](https://asgi.readthedocs.io/en/latest/specs/lifespan.html) und definiert Events namens `startup` und `shutdown`.

/// info | Info

Weitere Informationen zu Starlettes `lifespan`-Handlern finden Sie in [Starlettes Lifespan-Dokumentation](https://www.starlette.dev/lifespan/).