- author: Nick Cortale
    author_link: https://nickc1.github.io/
    link: https://nickc1.github.io/api,/scikit-learn/2019/01/10/scikit-fastapi.html
    title: 'FastAPI and Scikit-Learn: Easily Deploy Models'
  - author: Errieta Kostala
    author_link: https://dev.to/errietta
    link: https://dev.to/errietta/introduction-to-the-fastapi-python-framework-2n10
    title: Introduction to the fastapi python framework

It will have the database connection open at the beginning and will just wait some seconds before replying back. And each new request will wait one second less.

This will easily let you test that your app with Peewee and FastAPI is behaving correctly with all the stuff about threads.

participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Camila")
        function ->> code: return stored result
    end

    rect rgba(0, 255, 0, .1)

version: 2
updates:
  # GitHub Actions
  - package-ecosystem: "github-actions"
    directory: "/"
    schedule:
      interval: "daily"
    commit-message:
      prefix: ⬆
  # Python
  - package-ecosystem: "pip"
    directory: "/"
    schedule:
      interval: "monthly"
    commit-message:

# Templates

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies

Install `jinja2`:

<div class="termy">

```console
$ pip install jinja2

---> 100%
```

</div>

participant function as say_hi()
participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")
        function ->> execute: 执行函数代码
        execute ->> code: 返回结果
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Camila")
        function ->> code: 返回存储的结果
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")

**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry?

But you can use any relational database that you want.

Here we'll see an example using <a href="https://www.sqlalchemy.org/" class="external-link" target="_blank">SQLAlchemy</a>.

You can easily adapt it to any database supported by SQLAlchemy, like:

* PostgreSQL
* MySQL
* SQLite
* Oracle
* Microsoft SQL Server, etc.

5. Copy the `./app` directory inside the `/code` directory.

    As this has all the code which is what **changes most frequently** the Docker **cache** won't be used for this or any **following steps** easily.

    So, it's important to put this **near the end** of the `Dockerfile`, to optimize the container image build times.

6. Set the **command** to use `fastapi run`, which uses Uvicorn underneath.