On 9 Oct 2018, at 23:02, Gregory Szorc <gregory.szorc@gmail.com> wrote:

While we're here, CPython might want to look into getdirentriesattr() as
a replacement for readdir(). We switched to it in Mercurial several
years ago to make `hg status` operations significantly faster [2]. I'm
not sure if it will yield a speedup on APFS though. But it's worth a
try. (If it does, you could probably make
os.listdir()/os.scandir()/os.walk() significantly faster on macOS.)

Note that getdirentriesattr is deprecated as of macOS 10.10, getattrlistbulk
is the non-deprecated replacement (introduced in 10.10).