And to help in getting a reply, here is the trimmed-down results for CPython 3.7 to compare against:

    [('cp37', 'cp37m', 'macosx_10_13_x86_64'),
    …
     ('cp37', 'abi3', 'macosx_10_13_x86_64'),
    …
      ('cp37', 'none', 'macosx_10_13_x86_64'),
    …
     ('cp36', 'abi3', 'macosx_10_13_x86_64'),
    …
      ('cp35', 'abi3', 'macosx_10_13_x86_64'),
    …
      ('cp34', 'abi3', 'macosx_10_13_x86_64'),
    …
     ('cp33', 'abi3', 'macosx_10_13_x86_64'),
    …
     ('cp32', 'abi3', 'macosx_10_13_x86_64'),
    …
     ('py3', 'none', 'macosx_10_13_x86_64'),
    …
     ('cp37', 'none', 'any'),
     ('cp3', 'none', 'any'),
     ('py37', 'none', 'any'),
     ('py3', 'none', 'any'),
     ('py36', 'none', 'any'),
     ('py35', 'none', 'any'),
     ('py34', 'none', 'any'),
     ('py33', 'none', 'any'),
     ('py32', 'none', 'any'),
     ('py31', 'none', 'any'),
 ('py30', 'none', 'any')]

So, it re-iterate the questions:
  1. What is ('pp3', 'none', 'any') supposed to represent for PyPy3? Since the version of the interpreter is PyPy3 6.0 the lack of major version number seems like a bug more than a purposeful interpreter version (and there's only a single project -- cliquet -- that has a wheel that's compatible with that tag triple and it's not even for their latest release).
  2. Why does CPython have (*, 'none', 'any') from the version of the interpreter down to Python 3.0 plus generically Python 3 while PyPy3 only gets generic Python 3?
  3. Why isn't (*, 'none', platform) listed from Python 3.7 to 3.0 for either CPython or PyPy3? I understand not iterating through all versions when an ABI is involved (without knowing exactly which versions are compatible like abi3), but this triple seems safe to iterate through as a fallback just as much as (*, 'none', 'any'). Maybe because it's too ambiguous to know how important such a fallback would be between e.g. ('py36', 'none', 'macosx_10_13_x86_64') and ('py37', 'none', 'any'), and so why bother when the older version triples are there just for a safety net to have at least some chance of a match?
  4. I still think ('py360', 'none', 'any') is a bug. ;)

P.S.: The ('py3', 'none', 'macosx_10_13_x86_64') triple being between e.g. ('pp360', 'none', 'macosx_10_13_x86_64') and ('pp360', 'none', 'any') is really messing with my head and making the code to generate supported triples a bit less elegant. ;)

On Sat, 25 Aug 2018 at 15:03 Brett Cannon <brett@python.org> wrote:
I noticed that for PyPy3, the tag triples considered compatible were (roughly; trimmed out the long list of macOS versions):

    [('pp360', 'pypy3_60', 'macosx_10_13_x86_64'),
     ('pp360', 'none', 'macosx_10_13_x86_64'),
      ('py3', 'none', 'macosx_10_13_x86_64'),
     ('pp360', 'none', 'any'),
     ('pp3', 'none', 'any'),
     ('py360', 'none', 'any'),
     ('py3', 'none', 'any')]

Now the first question I have is about ('pp3', 'none', 'any'). Is this meant to be a generic thing for any interpreter of the interpreter implementation and major version, or is this special to CPython and PyPy3?

Question two is why isn't there a ('py35', 'none', 'any') or ('py34', 'none', 'any') and older to py30 after py3 like there is for CPython? Seems like if they are just source then they should be compatible as much as CPython.

Question three is why isn't there a ('py35', 'none', 'macosx_10_13_x86_64') for PyPy3 or CPython 3.7? I can't figure out what a Python- and platform-specific wheel but agnostic to API wouldn't ever work?

And I'm assuming ('py360', 'none', 'any'), isn't legitimate since that makes no sense. ;)