Python biedt ondersteuning voor optionele "type hints" (ook wel "type annotaties" genoemd).

Deze **"type hints"** of annotaties zijn een speciale syntax waarmee het <abbr title="bijvoorbeeld: str, int, float, bool">type</abbr> van een variabele kan worden gedeclareerd.

Door types voor je variabelen te declareren, kunnen editors en hulpmiddelen je beter ondersteunen.

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):

```Python hl_lines="16"
{!> ../../docs_src/body/tutorial004_py310.py!}
```

////

🔢 🔢 🔜 🤔 ⏩:

* 🚥 🔢 📣 **➡**, ⚫️ 🔜 ⚙️ ➡ 🔢.
* 🚥 🔢 **⭐ 🆎** (💖 `int`, `float`, `str`, `bool`, ♒️) ⚫️ 🔜 🔬 **🔢** 🔢.
* 🚥 🔢 📣 🆎 **Pydantic 🏷**, ⚫️ 🔜 🔬 📨 **💪**.

/// note

FastAPI 🔜 💭 👈 💲 `q` 🚫 ✔ ↩️ 🔢 💲 `= None`.

		// e.g. mysql8.0 doc: https://dev.mysql.com/doc/refman/8.0/en/sql-prepared-statements.html
		var (
			preparedStmtTx   *PreparedStmtTX
			isPreparedStmtTx bool
		)
		// close prepared statement, because SavePoint not support prepared statement.
		if preparedStmtTx, isPreparedStmtTx = db.Statement.ConnPool.(*PreparedStmtTX); isPreparedStmtTx {

		bucketName string
		accessKey  string
		secretKey  string
		// expected Response.
		expectedRespStatus int
		locationResponse   []byte
		errorResponse      APIErrorResponse
		shouldPass         bool
	}{
		// Test case - 1.
		// Tests for authenticated request and proper response.
		{
			bucketName:         bucketName,
			accessKey:          credentials.AccessKey,
			secretKey:          credentials.SecretKey,

</p>

<pre>
const c = 3 &lt; 4            // c is the untyped boolean constant true

type MyBool bool
var x, y int
var (
	// The result of a comparison is an untyped boolean.
	// The usual assignment rules apply.
	b3        = x == y // b3 has type bool
	b4 bool   = x == y // b4 has type bool
	b5 MyBool = x == y // b5 has type MyBool
)
</pre>

<p>

You can use the same type declarations with `str`, `float`, `bool` and many other complex data types.

Several of these are explored in the next chapters of the tutorial.

## Order matters

When creating *path operations*, you can find situations where you have a fixed path.

Puedes usar las mismas declaraciones de tipos con `str`, `float`, `bool` y otros tipos de datos más complejos.

Exploraremos varios de estos tipos en los próximos capítulos del tutorial.

## El orden importa

}

TF_Function* TF_FunctionImportFunctionDef(const void* proto, size_t proto_len,
                                          TF_Status* status) {
  tensorflow::FunctionDef fdef;
  bool success = fdef.ParseFromArray(proto, proto_len);
  if (!success) {
    status->status = InvalidArgument(
        "Invalid FunctionDef given to TF_FunctionImportFunctionDef");
    return nullptr;
  }

pkg syscall (freebsd-386-cgo), type SysProcAttr struct, Noctty bool
pkg syscall (freebsd-386-cgo), type SysProcAttr struct, Ptrace bool
pkg syscall (freebsd-386-cgo), type SysProcAttr struct, Setctty bool
pkg syscall (freebsd-386-cgo), type SysProcAttr struct, Setpgid bool
pkg syscall (freebsd-386-cgo), type SysProcAttr struct, Setsid bool
pkg syscall (freebsd-386-cgo), type Timespec struct, Nsec int32