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author | Lars Gustäbel <lars@gustaebel.de> | 2010-03-03 11:55:48 (GMT) |
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committer | Lars Gustäbel <lars@gustaebel.de> | 2010-03-03 11:55:48 (GMT) |
commit | 6458104188813b0165f95fcc0cf48bf02a276f42 (patch) | |
tree | 759342dacad1d17021d1e2cab41c2523e4bc2570 /Lib | |
parent | 8af970ab58e371def3779f6dd2fffe0c389c79d4 (diff) | |
download | cpython-6458104188813b0165f95fcc0cf48bf02a276f42.zip cpython-6458104188813b0165f95fcc0cf48bf02a276f42.tar.gz cpython-6458104188813b0165f95fcc0cf48bf02a276f42.tar.bz2 |
Issue #7232: Add support for the context manager protocol
to the TarFile class.
Diffstat (limited to 'Lib')
-rw-r--r-- | Lib/tarfile.py | 14 | ||||
-rw-r--r-- | Lib/test/test_tarfile.py | 60 |
2 files changed, 74 insertions, 0 deletions
diff --git a/Lib/tarfile.py b/Lib/tarfile.py index eb42055..45928fd 100644 --- a/Lib/tarfile.py +++ b/Lib/tarfile.py @@ -2411,6 +2411,20 @@ class TarFile(object): """ if level <= self.debug: print >> sys.stderr, msg + + def __enter__(self): + self._check() + return self + + def __exit__(self, type, value, traceback): + if type is None: + self.close() + else: + # An exception occurred. We must not call close() because + # it would try to write end-of-archive blocks and padding. + if not self._extfileobj: + self.fileobj.close() + self.closed = True # class TarFile class TarIter: diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py index 938e48b..353551d 100644 --- a/Lib/test/test_tarfile.py +++ b/Lib/test/test_tarfile.py @@ -1292,6 +1292,65 @@ class LimitsTest(unittest.TestCase): tarinfo.tobuf(tarfile.PAX_FORMAT) +class ContextManagerTest(unittest.TestCase): + + def test_basic(self): + with tarfile.open(tarname) as tar: + self.assertFalse(tar.closed, "closed inside runtime context") + self.assertTrue(tar.closed, "context manager failed") + + def test_closed(self): + # The __enter__() method is supposed to raise IOError + # if the TarFile object is already closed. + tar = tarfile.open(tarname) + tar.close() + with self.assertRaises(IOError): + with tar: + pass + + def test_exception(self): + # Test if the IOError exception is passed through properly. + with self.assertRaises(Exception) as exc: + with tarfile.open(tarname) as tar: + raise IOError + self.assertIsInstance(exc.exception, IOError, + "wrong exception raised in context manager") + self.assertTrue(tar.closed, "context manager failed") + + def test_no_eof(self): + # __exit__() must not write end-of-archive blocks if an + # exception was raised. + try: + with tarfile.open(tmpname, "w") as tar: + raise Exception + except: + pass + self.assertEqual(os.path.getsize(tmpname), 0, + "context manager wrote an end-of-archive block") + self.assertTrue(tar.closed, "context manager failed") + + def test_eof(self): + # __exit__() must write end-of-archive blocks, i.e. call + # TarFile.close() if there was no error. + with tarfile.open(tmpname, "w"): + pass + self.assertNotEqual(os.path.getsize(tmpname), 0, + "context manager wrote no end-of-archive block") + + def test_fileobj(self): + # Test that __exit__() did not close the external file + # object. + fobj = open(tmpname, "wb") + try: + with tarfile.open(fileobj=fobj, mode="w") as tar: + raise Exception + except: + pass + self.assertFalse(fobj.closed, "external file object was closed") + self.assertTrue(tar.closed, "context manager failed") + fobj.close() + + class GzipMiscReadTest(MiscReadTest): tarname = gzipname mode = "r:gz" @@ -1371,6 +1430,7 @@ def test_main(): PaxUnicodeTest, AppendTest, LimitsTest, + ContextManagerTest, ] if hasattr(os, "link"): |