PyNoon Plus Lesson 4

Warm-Up Exercise

• Think of questions or topics you’d like to bring up during our wrap-up discussion
• Continue work on your Personal Python Project

Thanks

• To the host for the great venue!
• To our sponsors

Administrivia

• Fire escapes
• Toilets
• Cleaning up after ourselves
• WiFi

PyNoon Finale: What Next?

• 10,000 foot view of topics not covered so far
• Recommendations for continuing learning
• Wrap-up discussion - start thinking of questions

Object Oriented Programming (OOP)

from dataclasses import dataclass

@dataclass
class InventoryItem:
    """Class for keeping track of an item in inventory."""
    name: str
    unit_price: float
    quantity_on_hand: int = 0

    def total_cost(self) -> float:
        return self.unit_price * self.quantity_on_hand

my_item = InventoryItem(name='Notebook', unit_price=9.99, quantity_on_hand=5)
print(f'We have {my_item.total_cost()} worth of {my_item.name}')

Python Scripting

The command line

• Every operating system has a command-line/command-prompt/terminal
• It lets you run programs with text commands
  • Similar to the Python shell

Running other programs

• Run commands from Python with:
  • subprocess
  • sh (pip-installable)

Command line interfaces (CLIs)

argparse lets you specify arguments for a command-line interface:

Also see:

Internet-of-Things

• opencv and Pillow for processing video streams and images (e.g. home security)

Internet-of-Things

• Raspberry Pi is a cheap and popular computer for IoT use cases
• MicroPython for microcontrollers
• Related: Send messages or build a bot for chat apps like Slack:

from slack_sdk import WebClient

client = WebClient(token='YOUR_SLACKBOT_TOKEN')

client.chat_postMessage(channel='#random', text='Hello world!')

Python Web Development

Flask - the simplest option

from flask import Flask

app = Flask(__name__)

@app.route("/")
def hello_world():
    return "<p>Hello, World!</p>"

Database-backed web applications

• FastAPI - modern option for APIs
• Django - saves you from re-inventing wheels
  • Wagtail - Content Management System for Django

Project Best Practices

Project structure

• Split code into modules (.py files) of functions
• Include a README and LICENSE
• Example: github.com/ben-denham/labtech

Documentation

• Give variables, functions, and files informative names!
• Write docstrings for your modules, functions, and variables
  • Follow a style guide for documenting arguments and return values
• Use type hints to document and check the data types of function arguments and return values
• MkDocs can generate documentation from Markdown files, docstrings, and type hints

Tooling

• Manage pip dependencies with rye
• Automated testing
  • Unit tests for individual functions, e.g. pytest
  • End-to-end tests, e.g. browser automation with Selenium
• Linting to check code style, e.g. ruff
• Version control to track file changes, e.g. git

Miscellaneous

• Python coming to Excel soon
• Distributed Computing:
  • PySpark
  • Dask
• Game development:
  • PyGame engine for 2D games
  • Pyxel for retro games
  • Panda3D, Ursina, and Harfang3D for 3D games

The Python Community

• Python New Zealand
  • KiwiPycon - videos on YouTube
  • Meetups
  • Mailing list and Slack channel
• Community Python module and tool development on GitHub and GitLab

Continuing Your Learning

• Work on a project you care about!
• Online courses, e.g. Python for Everybody
• Real Python Tutorials
• Full Stack Python
• Automate the Boring Stuff with Python
• The official Python documentation

Wrap-Up Discussion

• Would you be interested in a follow-up course?
• Would you want to repeat this course?
• Would you be interested in an on-going meetup?