Running test_zipfile64 from command line (i.e., ./python Lib/test/test_zipfile64.py) I get two ResourceWarnings:

» ./python Lib/test/test_zipfile64.py                                                     
..Lib/test/test_zipfile64.py:82: ResourceWarning: unclosed file <_io.BufferedRandom name=4>
  for f in TemporaryFile(), TESTFN2:
.Lib/test/test_zipfile64.py:75: ResourceWarning: unclosed file <_io.BufferedRandom name=4>
  for f in TemporaryFile(), TESTFN2:
.
----------------------------------------------------------------------
Ran 4 tests in 356.228s

OK

Wasn't able to test with "-m test" even with -uall. Will try again tomorrow.

It looks like it is disabled from the regular test suite on purpose:

# XXX(nnorwitz): disable this test by looking for extra largfile [sic] resource
# which doesn't exist.  This test takes over 30 minutes to run in general
# and requires more disk space than most of the buildbots.
support.requires(
        'extralargefile',
        'test requires loads of disk-space bytes and a long time to run'
    )

I’m not sure why the proper “largefile” flag cannot be used: “It is okay to run some test that may create huge files. These tests can take a long time and may consume >2GB of disk space temporarily.”

As for the reported problem, perhaps the TemporaryFile() call sites should have a “with” statement added.

The purpose was to exclude it from run with -uall. It is norm if one or two test methods are needed the "largefile" flag. But if all methods in a test file create large files, running this test file becomes a pain.

Thanks, Serhiy. Running the test with test module: ./python -m test -v test_zipfile64
doesn't produce the same warning. With this patch the warning is gone in command-line mode too.

I haven't looked to verify that it's not an issue on 3.5 or earlier versions, but then I'm not sure about policy on that anyway.

Patch looks fine according to my limited understanding of the zipfile module.

New changeset baec3e2e1b1f by Serhiy Storchaka in branch '3.5':
Issue #25801: Fixed resource warnings in test_zipfile64.
https://hg.python.org/cpython/rev/baec3e2e1b1f

New changeset 32051701a49d by Serhiy Storchaka in branch '2.7':
Issue #25801: Fixed resource warnings in test_zipfile64.
https://hg.python.org/cpython/rev/32051701a49d

New changeset 2193f8b956de by Serhiy Storchaka in branch 'default':
Issue #25801: Fixed resource warnings in test_zipfile64.
https://hg.python.org/cpython/rev/2193f8b956de

Thank you for your patch SilentGhost.