If you look at the documentation for os.chmod(), it says:
"mode may take one of the following values (as defined in the stat
module)..."

and then lists a number of constants from the stat module (stat.S_ISUID,
stat.S_ISGID, etc.)

I cannot seem to find these constants defined anywhere on the stat
module page.  May I suggest that these constants be defined in the
documentation for os.chmod(), to make it easier on the user?

Since the constants are listed in the os.chmod section of the manual, do
I understand that you are suggesting that the eplanations of the
meanings of the flags from the chmod man page be added to that list?

I observe that in the unix man pages the flags are documented both in
the chmod(2) man page and the stat(2) man page, with somewhat different
text.  I'm not sure this informational redundancy is good...and I'd be
inclined to put the docs in the stat module docs where the flags are
actually defined.  They will then be hotlinked from the flag list in
os.chmod.

I agree with David.

I've added the documentation of the flags defined in the stat module in
r73778, with the os.chmod references to the hyperlinked.  The
descriptions are taken from the linux stat(2) page, so if anyone spots
any cross-platform inaccuracies let me know.  (As far as I can see the
flags are defined on Windows, they are just meaningless there, for the
most part).