"Operation" here refers to one of the HTTP "methods".

One of:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...and the more exotic ones:

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

In the HTTP protocol, you can communicate to each path using one (or more) of these "methods".

---

When building APIs, you normally use these specific HTTP methods to perform a specific action.

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

## **Typer**, a CLI-ok FastAPI-ja

@app.get("/items/{item_id}")
def main(
    item_id: int = Path(default=..., gt=0),
    query: str = Query(default=..., max_length=10),
    session: str = Cookie(default=..., min_length=3),
    x_trace: str = Header(default=..., title="Tracing header"),
):
    return {"message": "Hello World"}
```

...all these parameters are required because the default value is `...` (Ellipsis).

* Với request `PUT` tới `/items/{item_id}`, đọc body như JSON:
    * Kiểm tra xem nó có một thuộc tính bắt buộc kiểu  `str` là `name` không?
    * Kiểm tra xem nó có một thuộc tính bắt buộc kiểu `float` là `price` không?
    * Kiểm tra xem nó có một thuộc tính tùy chọn là `is_offer` không? Nếu có, nó phải có kiểu `bool`.
    * Tất cả những kiểm tra này cũng được áp dụng với các JSON lồng nhau.

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

## **Typer**, CLI-ların FastAPI-ı

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

## **Typer**, FastAPI ti CLIs

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

## **Typer**, the FastAPI of CLIs

<div style="text-align: right; margin-right: 10%;">Deon Pillsbury - <strong>Cisco</strong> <a href="https://www.linkedin.com/posts/deonpillsbury_cisco-cx-python-activity-6963242628536487936-trAp/" target="_blank"><small>(ref)</small></a></div>

---

## **Typer**, the FastAPI of CLIs