Python Advanced (2022-03-15 - 2022-03-17, 2022-03-31)

Training Information

• Python: More Language Features

• Python Programming

• Jupyter Notebook

  • Structure

  • Entire Notebook

  • download

• Github Repository

• Predecessor training: Python Basics (2022-02-23 - 2022-02-25)

2022-03-15

• Exercise: Primeness (Function)

• Exercise: Eliminate Empty/Comment-Only Lines

• Encoding

2022-03-16

Good morning!

• Live-hack eval()

  • notebook (first)

  • dict-from-cmdline.py

• The exec() Function (exec-context.py)

• Positional and Keyword Arguments (args-kwargs.py)

• Closures (closure.py)

• Decorators (decorator.py)

Continue with exercises: CSV ⟶ modularization

• CSV Files

• Exercise: Read CSV File (csv.reader)

• Exercise: Read CSV File (csv.dictreader)

Test Driven Development

(Mostly from Is Software A Craft? Software Is A Craft! ⟶ Clean Code)

I had stated my strong opinion about (excess) debugger usage. (In short words, debuggers are from hell when you use one to comprehend code that is otherwise incomprehensible - the same holds true for excess IDE usage).

Discussion, naturally (thank you Alex). Decided to switch to test driven development, provocantly. Based upon pytest Introduction, By Example, hacked the following topics while introducing TDD:

• Exercise: Refactoring - Extract CSV Reading Into Function (csv.dictreader)

• Modules and Packages

• Exercise: Refactoring - Extract Both CSV Formats Into Module

(“Project” here)

2022-03-17

Revisit yesterday’s mess …

• Show userdb “project” on Github

  Plan for exercises: test driven

  • Manager writes test (and commits/pushes to Github)

  • Team mates download ZIP file (also done via the “Code” button on project’s main page)

  • Team mates hack

• Python Package Index

• Virtual Environments

• pytest Introduction, By Example

Continue with mess …

• Elaborate on class User ⟶ require that constructor raise a dedicated exception if, for example, id is not an integer (requirement here)

• More requirements … (here)

• More …

  • User “invalid ID” exception

  • “Duplicate ID in DB” exception

  • Common exception base class

  • collections.defaultdict

  • Databases

    • sqlite3 user database test

    • CSV to database program

2022-03-31

• Python Package Index

• Virtual Environments

Links

• Raymond Hettinger - Super considered super! - PyCon 2015. Raymond Hettinger, revolving around super() and MRO.

• Transforming Code into Beautiful, Idiomatic Python. Raymond Hettinger, reiterating his favorite phrase: “There must be a better way”. (Hettinger is a “Python Core Developer”.)

  (He uses Python 2 though.)

• Raymond Hettinger, Keynote on Concurrency, PyBay 2017: Raymond Hettinger covering most if not all aspects and possiblities of concurrency. Very informative, very concise, covering

  • Multithreading

  • Multiprocessing

  • Async; I didn’t even mention that. asyncio. Me big fan.

• Python Tutorial: pip - An in-depth look at the package management system, by Corey Schafer

• Python Tutorial: VENV (Windows) - How to Use Virtual Environments with the Built-In venv Module: Corey Schafer again. Virtual environments are kind of an isolated development sandbox, solving a similar problem as containers do, but much more lightweight and Python only.

• Python Tutorial: Decorators - Dynamically Alter The Functionality Of Your Functions, by Corey Schafer