def test_uncloseable_file(self):

        class MyFileLike(object):
            def __init__(self, foobar):
                self._foobar = foobar

            def read(self, n):
                return self._foobar.read(n)

            def seek(self, offset, whence=os.SEEK_SET):
                self._foobar.seek(offset, whence)

            def tell(self):
                return self._foobar.tell()


        with open(self.data('test0.fits'), 'rb') as f:
            fileobj = MyFileLike(f)

            with fits.open(fileobj) as hdul1:
                with fits.open(self.data('test0.fits')) as hdul2:
                    assert hdul1.info(output=False) == hdul2.info(output=False)
                    for hdu1, hdu2 in zip(hdul1, hdul2):
                        assert hdu1.header == hdu2.header
                        if hdu1.data is not None and hdu2.data is not None:
                            assert np.all(hdu1.data == hdu2.data)
Regression test for https://github.com/astropy/astropy/issues/2356
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/tests/test_core.py/TestFileFunctions.test_uncloseable_file