I already see my name change will cause problems. The tarfile.py (Lib/tarfile.py:277) module relies on the function being named 'filemode'.

As the stat.filemode function is relatively new, I don't know how many other modules rely on it. I changed the name because I thought the new name (mode2str) better described what the function does, and is orthogonal to the reverse function (str2mode).

But, of course, I've no issue with whatever the functions are finally named... I'll leave the decision to someone with a bit more experience.