PEP

PEP stands for Python Enhancement Proposal. It is the design document used to propose changes to Python, including the language syntax, the standard library, or the development process. A PEP should articulate the problem, propose a concrete solution, and justify the change with rationale and an assessment of backward compatibility and potential impact. Although presented as a document, a PEP is the formal mechanism by which the Python community drafts and debates significant changes before they are implemented.

The PEP process is open to anyone. A proposal is drafted and assigned a unique number by PEP editors. PEPs are discussed publicly on mailing lists and issue trackers, with feedback from core developers and the broader community. They pass through a lifecycle with statuses such as Draft, Proposed, Accepted, Deferred, Rejected, and Final. The intent is to reach broad consensus before a change is implemented in a Python release.

PEPs come in three types: Standards Track (defining language features or the standard library API), Informational (documenting guidelines or ancillary information), and Process (describing or modifying development procedures). A PEP typically includes sections such as title, author, status, type, and a detailed specification, along with rationale, backward compatibility considerations, implementation plan, tests, and references.

Notable PEPs include PEP 8, the Python style guide, and PEP 20, The Zen of Python, among others that have guided language features and library changes. The PEP mechanism provides a transparent, community-driven path from proposal to implementation and release, shaping the evolution of Python over time.

All official PEPs are archived in the Python Enhancement Proposals repository and on the Python.org site, ensuring publicly accessible documentation of proposals, discussions, and decisions.