Some suggestions for
https://docs.python.org/3.9/c-api/sys.html#c.PySys_AddAuditHook
https://docs.python.org/3.9/library/sys.html#sys.addaudithook

"Adds to the collection of active auditing hooks"
"Adds the callable hook to the collection of active auditing hooks"

Change 'Adds' to 'Add' or maybe 'Append' (see near below).
Insert 'the callable hook' in PySys version.
Change 'collection' to 'sequence' or 'list' (and change verb to 'append') since order is important.

PySys version:

I think the 'userData' explanation should be closer to the top.

Grammar: "Functions in the runtime and standard library that raise events include the details in each function’s documentation and listed in the audit events table." is not a proper sentence. Its 'skeleton' is "Functions ... include the details ... and listed ... .

Either change 'include the details' to 'are detailed' and 'listed' to 'are listed' or split into two sentences:

"Functions in the runtime and standard library that raise events are listed in the audit events table. Details are in each function’s documentation.

Both, again:

"raises a auditing event". 'a' should be 'an'. To me, this is slightly confusing because Python raises exceptions, but auditing events are not exceptions and do not normally abort execution. Perhaps "This call is a 'sys.addaudithook' event with no arguments that triggers an audit call."

https://docs.python.org/3.9/c-api/sys.html#c.PySys_Audit
https://docs.python.org/3.9/library/sys.html#sys.audit

Change 'Raises' to 'Raise'.

https://docs.python.org/3.8/library/audit_events.html

On pydev, Steve said "(though some won't be raised until 3.8.1... we should probably mark those, or at least update that page to warn that events may have been added over time)."

Thanks Terry, this is great!

Agree with everything apart from not liking "raise" - I think "raise an event" is totally fine usage, and certainly better than "triggers an audit call" (since it may not, if nobody's listening). Plus PEP-578 is full of "raise", and we're not going to go edit all of that :)

I agree on consistency. I will make a PR for you to review.

Do you think a minimal code example might help? Running ...

import sys

def hook(name, args):
    if name.startswith('compile'):
        print(name, args)

sys.addaudithook(hook)
compile('a = 1', '<dummy>', 'exec')

# prints

compile (b'a = 1', '<dummy>')

My own interest is learning about the socket connecting an IDLE GUI process and the user code run process. The following in the two startup files:

def hook(name, args):
    if name.startswith('socket'):
        print('I', name, args)  # I/R in the IDLE/run processes.
sys.addaudithook(hook)

results in:

I socket.gethostname ()
R socket.gethostname ()
I socket.bind (<socket.socket fd=796, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0>, ('127.0.0.1', 0))
R socket.bind (<socket.socket fd=796, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0>, ('127.0.0.1', 0))
R socket.connect (<socket.socket fd=816, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0>, ('127.0.0.1', 62119))
I socket.__new__ (<socket.socket fd=-1, family=AddressFamily.AF_UNSPEC, type=0, proto=0>, 2, 1, 0)
R socket.__new__ (<socket.socket fd=-1, family=AddressFamily.AF_UNSPEC, type=0, proto=0>, 2, 1, 0)

To go further, I might wrap socket.socket.send/recv with functions that call sys.audit.

New changeset e563a15 by Steve Dower (Terry Jan Reedy) in branch 'master':
bpo-38892: Improve docs for audit event (GH-17361)
e563a15

Thanks Terry!

New changeset 86d9933 by Miss Islington (bot) in branch '3.8':
bpo-38892: Improve docs for audit event (GH-17361)
86d9933