Lesson 1

• Install Tools
• Create Project
• VS Code Finetuning
  • Code Formatting
  • Linting
  • Debugging

Install Tools

• Python 3.9 or later
  My suggestion ist to use the latest version posibile.

• Visual Studio Code

  • Plugins:
    • Python (with Pylance & Debugger)
    • Black Formatter
    • Flake8
    • isort
  • Optional Plugins:
    • YAML
    • Tiltfile
    • Kubernetes
    • Docker
    • Markdown Preview
    • Jupyter

• Poetry
  using pip (outside virtualenv), pipx or brew (macos)

• Tilt.dev

Create Project

mkdir dispo
poetry init
# do not define dependencies

See result in pyproject.toml file.

Create WebServer

poetry add fastapi "uvicorn[standart]"

With poetry add the package will also be installed. Use poetry install if the dependencies are already declared.

You must create an README.md file, otherwise poetry install will fail.

Let's start with our first code snippet:

#dispo/main.py
from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def hello_world():
    return {"message": "hello world"}

To start the app:

poetry shell
uvicorn main:app

Check http://localhost:8000

Swagger/OpenApi is already included, see http://localhost:8000/docs.

VS Code Finetuning

Virtual Environment

Virtual Environments will be recognized when activated at startup. If you prefer the the .venv inside the project directory, do poetry config virtualenvs.in-project true.

Code Formatting

We do use Black as formatter and isort for sorted import statements.

# >Preferences, Open User Settings(Json)
# settings.json - add following:
    "[python]": {
        "editor.defaultFormatter": "ms-python.black-formatter",
        "editor.formatOnSave": true,
        "editor.codeActionsOnSave": {
            "source.organizeImports": "explicit"
        },
    },
    "isort.args":["--profile", "black"],

To fix issues with black vs isort, add this

# pyproject.toml
[tool.isort]
profile = "black"

Linting

Is done by flake8. I do suggest to use the vs-code plugin for this. The following config will fix the usage with Black. This config could NOT be included in pyproject.toml.

# .flake8
[flake8]
max-line-length = 88
extend-ignore = E203

If you will now add a not needed import like import os then you should notice:

• Sorting the import statements on save
• A new Issue on Problems View

Debugging

Go to Run&Debug, get to create a launch.json - Python Debugger - FastAPI - defaults should be ok.

• start the app
• set a breakpoint
• check it