#### 🗒

❌:

```Python
connect_args={"check_same_thread": False}
```

...💪 🕴 `SQLite`. ⚫️ 🚫 💪 🎏 💽.

!!! info "📡 ℹ"

    🔢 🗄 🔜 🕴 ✔ 1️⃣ 🧵 🔗 ⏮️ ⚫️, 🤔 👈 🔠 🧵 🔜 🍵 🔬 📨.

    👉 ❎ 😫 🤝 🎏 🔗 🎏 👜 (🎏 📨).

    ✋️ FastAPI, ⚙️ 😐 🔢 (`def`) 🌅 🌘 1️⃣ 🧵 💪 🔗 ⏮️ 💽 🎏 📨, 👥 💪 ⚒ 🗄 💭 👈 ⚫️ 🔜 ✔ 👈 ⏮️ `connect_args={"check_same_thread": False}`.

#### The time to answer helps the attackers

At that point, by noticing that the server took some microseconds longer to send the "Incorrect username or password" response, the attackers will know that they got _something_ right, some of the initial letters were right.

* **Machine Learning**: it normally requires lots of "matrix" and "vector" multiplications. Think of a huge spreadsheet with numbers and multiplying all of them together at the same time.

    ```Python hl_lines="7  13"
    {!> ../../../docs_src/request_files/tutorial001_03.py!}
    ```

## Multiple File Uploads

It's possible to upload several files at the same time.

They would be associated to the same "form field" sent using "form data".

To use that, declare a list of `bytes` or `UploadFile`:

=== "Python 3.9+"

    ```Python hl_lines="10  15"

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

### Tags with Enums

If you have a big application, you might end up accumulating **several tags**, and you would want to make sure you always use the **same tag** for related *path operations*.

In these cases, it could make sense to store the tags in an `Enum`.

**FastAPI** supports that the same way as with plain strings:

```Python hl_lines="1  8-10  13  18"
{!../../../docs_src/path_operation_configuration/tutorial002b.py!}
```

from typing import List

import yaml
from fastapi import FastAPI, HTTPException, Request
from pydantic import BaseModel, ValidationError

app = FastAPI()


class Item(BaseModel):
    name: str
    tags: List[str]


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.model_json_schema()}},
            "required": True,
        },
    },

    * No entanto, existe uma solução para isso.
* Há uma extensão para o protocolo TLS (aquele que lida com a criptografia no nível TCP, antes do HTTP) chamado <a href="https://en.wikipedia.org/wiki/Server_Name_Indication" class="external-link" target="_blank"><abbr title="Server Name Indication">SNI</abbr></a>.
    * Esta extensão SNI permite que um único servidor (com um único endereço IP) tenha vários certificados HTTPS e atenda a vários domínios / aplicativos HTTPS.

<img src="/img/tutorial/websockets/image04.png">

And all of them will use the same WebSocket connection.

## Using `Depends` and others

In WebSocket endpoints you can import from `fastapi` and use:

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

They work the same way as for other FastAPI endpoints/*path operations*:

=== "Python 3.10+"

!!! info
    The parameter `summary` is available in OpenAPI 3.1.0 and above, supported by FastAPI 0.99.0 and above.

## Overriding the defaults

Using the information above, you can use the same utility function to generate the OpenAPI schema and override each part that you need.