* There is a **solution** to this, however.
* There's an **extension** to the **TLS** protocol (the one handling the encryption at the TCP level, before HTTP) called **<a href="https://en.wikipedia.org/wiki/Server_Name_Indication" class="external-link" target="_blank"><abbr title="Server Name Indication">SNI</abbr></a>**.

The word **program** is commonly used to describe many things:

* The **code** that you write, the **Python files**.
* The **file** that can be **executed** by the operating system, for example: `python`, `python.exe` or `uvicorn`.
* A particular program while it is **running** on the operating system, using the CPU, and storing things on memory. This is also called a **process**.

### What is a Process

* It contains an `app/main.py` file. As it is inside a Python package (a directory with a file `__init__.py`), it is a "module" of that package: `app.main`.
* There's also an `app/dependencies.py` file, just like `app/main.py`, it is a "module": `app.dependencies`.
* There's a subdirectory `app/routers/` with another file `__init__.py`, so it's a "Python subpackage": `app.routers`.

                        authId: oauth2.auth.name,
                        source: "auth",
                        level: "error",
                        message: oauthErrorMsg || "[Authorization failed]: no accessCode received from the server."
                    });
                }
            } else {
                oauth2.callback({auth: oauth2.auth, token: qp, isValid: isValid, redirectUrl: redirectUrl});

    This is useful when we use ConstrainedDecimal to represent Numeric(x,0)
    where a integer (but not int typed) is used. Encoding this as a float
    results in failed round-tripping between encode and parse.
    Our Id type is a prime example of this.

    >>> decimal_encoder(Decimal("1.0"))
    1.0

    >>> decimal_encoder(Decimal("1"))
    1
    """

# Request Files

You can define files to be uploaded by the client using `File`.

!!! info
    To receive uploaded files, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

    E.g. `pip install python-multipart`.

    This is because uploaded files are sent as "form data".

## Import `File`

Import `File` and `UploadFile` from `fastapi`:

=== "Python 3.9+"

    ```

=== "Python 3.8+"

    ```Python hl_lines="15  19  24"
    {!> ../../../docs_src/dependencies/tutorial001_02_an.py!}
    ```

!!! tip
    This is just standard Python, it's called a "type alias", it's actually not specific to **FastAPI**.

    But because **FastAPI** is based on the Python standards, including `Annotated`, you can use this trick in your code. 😎

### Support d'éditeurs

Tout le framework a été conçu pour être facile et intuitif d'utilisation, toutes les décisions de design ont été testées sur de nombreux éditeurs avant même de commencer le développement final afin d'assurer la meilleure expérience de développement possible.

👆 💪 📣 👈 🔢 💪 🙆 **📚 🆎**, 🖼, `int` ⚖️ `str`.

🐍 3️⃣.6️⃣ & 🔛 (✅ 🐍 3️⃣.1️⃣0️⃣) 👆 💪 ⚙️ `Union` 🆎 ⚪️➡️ `typing` & 🚮 🔘 ⬜ 🗜 💪 🆎 🚫.

🐍 3️⃣.1️⃣0️⃣ 📤 **🎛 ❕** 🌐❔ 👆 💪 🚮 💪 🆎 👽 <abbr title='also called "bitwise or operator", but that meaning is not relevant here'>⏸ ⏸ (`|`)</abbr>.

=== "🐍 3️⃣.6️⃣ &amp; 🔛"

    ```Python hl_lines="1  4"
    {!> ../../../docs_src/python_types/tutorial008b.py!}
    ```

But whenever you need them and go and learn them, know that you can already use them directly in **FastAPI**.

### Pydantic v1 `regex` instead of `pattern`

Before Pydantic version 2 and before FastAPI 0.100.0, the parameter was called `regex` instead of `pattern`, but it's now deprecated.

You could still see some code using it:

=== "Python 3.10+ Pydantic v1"

    ```Python hl_lines="11"