test_largefile.py 文件源码

def test_seek(self):
        if verbose:
            print('create large file via seek (may be sparse file) ...')
        with self.open(TESTFN, 'wb') as f:
            f.write(b'z')
            f.seek(0)
            f.seek(size)
            f.write(b'a')
            f.flush()
            if verbose:
                print('check file size with os.fstat')
            self.assertEqual(os.fstat(f.fileno())[stat.ST_SIZE], size+1)