I recently discovered this method is missing from Python 3. I started porting a project which depends on it (a tool that uploads an already-packaged package to a cheeseshop), but found the method missing on Python 3. According to the changelog, this commit landed in 2.7 and 3.2, but when I search the Mercurial repo for #7457, it seems it only landed in 2.7 (25aede62fc17). Perhaps the change was lost in the migration to Mercurial?

Since this behavior was not intentionally removed from Python 3 and has no suitable replacement (afaik), the functionality should be restored in 3.2+, as it is a regression from 2.7.