Also this class, because it defines __del__ too simply, will display a user-unfriendly error message when cleaning up a TemporaryDirectory object whose constructor raised an exception when attempting to create its temporary folder.

  For example try to create a TemporaryDirectory with prefix="aa>aa" on Windows. That should fail as folders there can not contain '>' characters and later on in the program you should get an error message something like this one:

Exception AttributeError: "'TemporaryDirectory' object has no attribute '_closed'" in <bound method TemporaryDirectory.cleanup of <tempfile.TemporaryDirectory object at 0x00CE1E10>> ignored

  Hope this helps.

[Sorry, did not know whether to add this as a separate issue as it seemed kind of related to this one.]