#443 Patching Multiprocessing

• rumdl - A Markdown Linter written in Rust
• * Coverage 7.10.0: patch*
• * aioboto3*
• * You might not need a Python class*
• Extras
• Joke

About the show

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• Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky)
• Brian: @brianokken@fosstodon.org / @brianokken.bsky.social
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Michael #1: rumdl - A Markdown Linter written in Rust

• via Owen Lamont
• Supports toml file config settings
• Install via uv tool install rumdl.
• ⚡️ Built for speed with Rust - significantly faster than alternatives
• 🔍 54 lint rules covering common Markdown issues
• 🛠️ Automatic fixing with -fix for most rules
• 📦 Zero dependencies - single binary with no runtime requirements
• 🔧 Highly configurable with TOML-based config files
• 🌐 Multiple installation options - Rust, Python, standalone binaries
• 🐍 Installable via pip for Python users
• 📏 Modern CLI with detailed error reporting
• 🔄 CI/CD friendly with non-zero exit code on errors

Brian #2: Coverage 7.10.0: patch

• Ned Batchelder

• Actually up to 7.10.2 as of today

• patch allows coverage to run better when a covered project uses

  • subprocesses
  • os._exit()
  • execv family of functions

• Looking at subprocess

  • “Coverage works great when you start your program with coverage measurement, but has long had the problem of how to also measure the coverage of sub-processes that your program created. The existing solution had been a complicated two-step process of creating obscure .pth files and setting environment variables. Whole projects appeared on PyPI to handle this for you.”

• From release notes

  for 7.10.0

  • A new configuration option: “[run] patch” specifies named patches to work around some limitations in coverage measurement. These patches are available:

    • patch = _exit lets coverage save its data even when <code>os._exit()</code> is used to abruptly end the process. This closes long-standing issue 310 as well as its duplicates: issue 312, issue 1673, issue 1845, and issue 1941.
    • patch = subprocess measures coverage in Python subprocesses created with <code>subprocess</code>, <code>os.system()</code>, or one of the <code>execv</code> or <code>spawnv</code> family of functions. Closes old issue 367 and duplicate issue 378.
    • patch = execv adjusts the <code>execv</code> family of functions to save coverage data before ending the current program and starting the next. Not available on Windows. Closes issue 43 after 15 years!

Michael #3: aioboto3

• via Pat Decker
• Wrapper to use boto3 resources with the aiobotocore async backend
• aiobotocore allows you to use near enough all of the boto3 client commands in an async manner just by prefixing the command with await.
• With aioboto3 you can now use the higher level APIs provided by boto3 in an asynchronous manner.

Brian #4: You might not need a Python class

• Adam Grant
• This is an important periodic reminder to everyone coming into Python from other languages.
  • Many other languages lean on classes a lot more than we need to in Python
• Adams suggestions
  • Simple Data Containers: Use Named Tuples or Data Classes
  • Stateless Utility Functions: Just Use Functions
  • Grouping Constants: Use Modules
  • Managing State with Simple Structures: Use Dictionaries or Lists
  • Simple One-off Operations: Use Lambdas or Comprehensions
    • I’ll add “just use functions”
  • Avoiding Complexity: Built-in Libraries
  • When You Actually Need a Class
    • I’ll add
      • You probably don’t
      • If you think you do, ask a friend. Friends don’t let friends create extraneous classes in Python.
      • If you think your case is an exception, it probably isn’t
      • If you think dataclasses aren’t right for you, check out attrs

Extras

Brian:

• PyPI Incident Report: Phishing Attack -Sent in by listener John Hagen
• Both of Adam Johnson’s recent-ish interviews are now up on Test & Code
  • 236: Git Tips for Testing - Adam Johnson
  • 235: pytest-django - Adam Johnson

Michael:

• Dive into uv webcast with me and Will Vincent

Joke: Default text editor