PEP 786: Precision and Modulo-Precision Flag format specifiers for integer fields

[jb2170]

Draft PR for new PEP 791

Sponsor Pending

There is a TODO section in the PEP that shall perish as the PEP is tweaked before even considering merging

Relevant discussions, issues, PRs linked

https://discuss.python.org/t/implement-precision-format-spec-for-int-type-data/80760
python/cpython#131926
python/cpython#74756

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
• 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: sponsor pending
• 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: everything but 80-column line length, so as to avoid tedious re-aligning during this draft stage
• 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: sponsor pending

Standards Track requirements

• PEP topic discussed in a suitable venue with general agreement that a PEP is appropriate
• Suggested sections included (unless not applicable)
  • Motivation: included in Rationale
  • Rationale
  • Specification: on the TODO list if an RFC 2119 style summary is needed
  • Backwards Compatibility
  • Security Implications: not needed?
  • How to Teach This: Examples And Teaching section
  • Reference Implementation
  • Rejected Ideas
  • Open Issues: None so far
• Python-Version set to valid (pre-beta) future Python version, if relevant: pending
• Any project stated in the PEP as supporting/endorsing/benefiting from the PEP formally confirmed such: none
• Right before or after initial merging, PEP discussion thread created and linked to in Discussions-To and Post-History

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📚 Documentation preview 📚: https://pep-previews--4365.org.readthedocs.build/

[AA-Turner]

If you get a sponsor, the next number is either 785 or 786.

[ncoghlan]

While I didn't see the original Discourse thread, I've definitely been bitten by the # vs field width problem, so I'd be happy to be listed as a PEP sponsor.

[hugovk]

Thanks, let's use 785 for #4357 and 786 here.