python: need to close file from mkstemp if I use fdopen?

Question

Which of the following is more correct?

fi, path = tempfile.mkstemp()
f = os.fdopen(fi, "w")
f.write(res)
f.close()
os.close(fi)

or:

fi, path = tempfile.mkstemp()
f = os.fdopen(fi, "w")
f.write(res)
f.close()

Answer 1

Check f.fileno(), it should be the same as fi. You should only ever close that file descriptor once, so the second is correct.

On Unix, the first causes an error:

>>> f.close()
>>> os.close(fi)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [Errno 9] Bad file descriptor