Thanks for reviewing!

> The name 'ensure_exist' for the new parameter strikes me as wrong, as well as too long for something that will nearly always be set to True. The function always ensures that the directory exists. The question is whether it is ok that it exist previously. I strongly suggest something shorter like 'exist_ok' as an alternative.


Yes, I guess you'are right, this parameter needs to be shorter.


> Does the use of 'base = support.TESTFN' ensure that the test junk gets cleaned up?

Yes, the MakedirTests.tearDown() method will try to look for the outermost directory of "@base/dir1/dir2/dir3/dir4/dir5/dir6", so it can ensure the test directory is cleaned up.


> * Location of error suppression: this patches posixfile.mkdir; 1675 wraps it with a new os.mkdir function that does the suppression. I can see an argument for each approach.

The purpose of posix_mkdir() is to simulate a shell mkdir command, so I think the function of "-p" option should goes in to this code. A wrapper makes code more complicated.


> * Propagation to parent directories: this passes exist_ok to parent mkdir(); 1675 passes exist_ok=True, so that it is never an error for parent directories to exist. This is a change in behavior and might be bad for the same reason we do not make exist_ok=True the default. In any case, I believe either patch could be changed to mimic the other.

It seems these two ways has the same effect, I have no opinion on which to prefer.


By adopting your parameter naming suggestion and a little coding style change, I update the patch.