Munyola / peps

Python Enhancement Proposals

Python Enhancement Proposals

The PEPs in this repo are published automatically on the web at https://www.python.org/dev/peps/. To learn more about the purpose of PEPs and how to go about writing one, please start reading at PEP 1. Note that PEP 0, the index PEP, is automatically generated and not committed to the repo.

Contributing to PEPs

See the Contributing Guidelines.

reStructuredText for PEPs

PEP source text should be written in reStructuredText format, which is a constrained version of plaintext, and is described in PEP 12. The pep2html.py processing and installation script knows how to produce the HTML for the PEP format.

To render the PEPs, you'll first need to install the requirements, (preferably in a fresh virtual environment):

python -m pip install -r requirements.txt

Generating the PEP Index

PEP 0 is automatically generated based on the metadata headers in other PEPs. The script handling this is genpepindex.py, with supporting libraries in the pep0 directory.

Checking PEP formatting and rendering

Please don't commit changes with reStructuredText syntax errors that cause PEP generation to fail, or result in major rendering defects relative to what you intend. To check building the HTML output for your PEP (for example, PEP 12) using the current default docutils-based system, run the pep2html.py script with your PEP source file as its argument; e.g. for PEP 12,

python pep2html.py pep-0012.rst

If you're on a system with make, you can instead execute, e.g.,

make pep-0012.rst

To generate HTML for all the PEPs, run the script/make without a PEP file argument.

By default, this will output a file (e.g. pep-0012.html) in the root directory, which you can view to see the HTML output of your PEP. Note that the custom CSS stylesheet is not used by default, so the PEP will look rather plain, but all the basic formatting produced by the reStructuredText syntax in your source file should be visible.

You can also view your PEP locally with the Sphinx-based builder, which will show the PEP exactly as it will appear on the preview of the new rendering system proposed in 676; see Rendering PEPs with Sphinx for details.

Finally, you can check for and fix common linting and spelling issues, either on-demand or automatically as you commit, with our pre-commit suite. See the Contributing Guide for details.

Generating HTML for Python.org

Python.org includes its own helper modules to render PEPs as HTML, with suitable links back to the source pages in the version control repository.

These can be found in the python.org repository.

When making changes to the PEP management process that may impact python.org's rendering pipeline:

• Clone the python.org repository.
• Get set up for local python.org development.
• Adjust PEP_REPO_PATH in pydotorg/settings/local.py to refer to your local clone of the PEP repository.
• Run ./manage.py generate_pep_pages as described the python.org docs.

Rendering PEPs with Sphinx

There is a Sphinx-rendered version of the PEPs at https://python.github.io/peps/ (updated on every push to main).

Warning: This version is not, and should not be taken to be, a canonical source for PEPs whilst it remains in preview (please report any rendering bugs). The canonical source for PEPs remains https://www.python.org/dev/peps/

Build PEPs with Sphinx locally

See the build documentation for full step by step instructions on how to install, build and view the rendered PEPs with Sphinx.

In summary, after installing the dependencies (preferably in a virtual environment) with:

python -m pip install -r requirements.txt

You can build the PEPs with sphinx by running, if your system has make:

make sphinx

Otherwise, execute the build.py script directly:

python build.py

The output HTML can be found under the build directory.

build.py usage

For details on the command-line options to the build.py script, run:

python build.py --help