Ben Finney writes:
Skip Montanaro has a PyPI package, ‘lockfile’ (currently marked "Beta") URL:http://pypi.python.org/pypi/lockfile that has such ambitions.
Should I make an even lower-level PEP to suggest inclusion of Skip's ‘lockfile’ package? Is that wise? Is it polite?
I would send your proposal for PIDlockfile to Skip. In your PEP, describe the relevant parts of the API explicitly in the PEP, with a footnote that you are deliberately extending the lockfile interface and currently intend to remain compatible with that interface.
Then talk to Skip about a PEP for including his package, or perhaps extending your PEP to include it. Which is better depends on details and how aggressively Skip would want to pursue inclusion of lockfile if your daemon package doesn't make it or takes a long time.
I don't know about "polite", but I think it would be unwise to try to PEP lockfile without Skip's explicit support.