PEP 845: Leading-Dot Value Patterns

[tmke8]

Basic requirements (all PEP Types)

• Read and followed PEP 1 & PEP 12
• File created from the latest PEP template
• PEP has next available number, & set in filename (pep-NNNN.rst), PR title (PEP 123: <Title of PEP>) and PEP header
  • Tip: find the next available number with pepotron — run uvx pepotron next (or pipx install pepotron then pep next)
• Title clearly, accurately and concisely describes the content in 79 characters or less
• Core dev/PEP editor listed as Author or Sponsor, and formally confirmed their approval
  • @ethanfurman offered to sponsor here
• Author, Status (Draft), Type and Created headers filled out correctly
• PEP-Delegate, Topic, Requires and Replaces headers completed if appropriate
• Required sections included
  • Abstract (first section)
  • Copyright (last section; exact wording from template required)
• Code is well-formatted (PEP 7/PEP 8) and is in code blocks, with the right lexer names if non-Python
• PEP builds with no warnings, pre-commit checks pass and content displays as intended in the rendered HTML
• Authors/sponsor added to .github/CODEOWNERS for the PEP

Standards Track requirements

• PEP topic discussed in a suitable venue with general agreement that a PEP is appropriate
  • https://discuss.python.org/t/pattern-matching-on-constants-that-arent-in-a-namespace-especially-sentinels/107916
• Suggested sections included (unless not applicable)
  • Motivation
  • Specification
  • Rationale
  • Backwards Compatibility
  • Security Implications
  • How to Teach This
  • Reference Implementation
  • Rejected Ideas
  • Open Issues
  • Acknowledgements
  • Footnotes
  • Change History
• Python-Version set to valid (pre-beta) future Python version, if relevant
• Any project stated in the PEP as supporting/endorsing/benefiting from the PEP formally confirmed such
• Right before or after initial merging, PEP discussion thread created and linked to in Discussions-To and Post-History

[read-the-docs-community]

Documentation build overview

📚 pep-previews | 🛠️ Build #34618540 | 📁 Comparing f826350 against latest (344e589)

  🔍 Preview build  

48 files changed · + 4 added · ± 44 modified

+ Added

• pep-0845/index.html
• pep-0846/index.html
• pep-0847/index.html
• pep-0825/appendix-metadata-consistency/index.html

± Modified

• index.html
• numerical/index.html
• pep-0000/index.html
• pep-0426/index.html
• pep-0501/index.html
• pep-0534/index.html
• pep-0585/index.html
• pep-0604/index.html
• pep-0654/index.html
• pep-0661/index.html
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[hugovk]

• Core dev/PEP editor listed as Author or Sponsor, and formally confirmed their approval

  • @ethanfurman offered to sponsor here

@ethanfurman Please could you confirm your sponsorship?

[ethanfurman]

Confirmed.

[hugovk]

@ethanfurman Please could you also review and approve if you're happy with it?

[ethanfurman]

Looks good!