> Is PyFile_FromFd and PyFile_FromFdEx fine with you or do you prefer a
> different name like PyFile_FromFD and PyFile_FromFDEx or
> PyFile_FromFileDescriptor?

Let's have a single function PyFile_FromFd(fd, name, mode, buffering,
encoding, newline).

> I've another question. The os.tmpfile method is using tmpfile() which
> returns a file pointer. Do I have to dup its file number and explictely
> close the file pointer as shown below or is a simple fileno() enough?

You should dup it; if you don't dup it, the fd will be closed when you
call fclose(), rendering it useless; or when you don't call fclose(),
you leak a FILE struct each time.