From ca715e56a13feabc15c368898df6511613d18987 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Sun, 4 Feb 2024 17:25:21 +0200 Subject: gh-69893: Add the close() method for xml.etree.ElementTree.iterparse() iterator (GH-114534) --- Doc/library/xml.etree.elementtree.rst | 5 ++ Doc/whatsnew/3.13.rst | 8 ++ Lib/test/test_xml_etree.py | 85 +++++++++++++++++++++- Lib/xml/etree/ElementTree.py | 9 ++- .../2024-01-24-17-25-18.gh-issue-69893.PQq5fR.rst | 2 + 5 files changed, 105 insertions(+), 4 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2024-01-24-17-25-18.gh-issue-69893.PQq5fR.rst diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst index bb6773c..75a7915 100644 --- a/Doc/library/xml.etree.elementtree.rst +++ b/Doc/library/xml.etree.elementtree.rst @@ -625,6 +625,8 @@ Functions target. Returns an :term:`iterator` providing ``(event, elem)`` pairs; it has a ``root`` attribute that references the root element of the resulting XML tree once *source* is fully read. + The iterator has the :meth:`!close` method that closes the internal + file object if *source* is a filename. Note that while :func:`iterparse` builds the tree incrementally, it issues blocking reads on *source* (or the file it names). As such, it's unsuitable @@ -647,6 +649,9 @@ Functions .. versionchanged:: 3.8 The ``comment`` and ``pi`` events were added. + .. versionchanged:: 3.13 + Added the :meth:`!close` method. + .. function:: parse(source, parser=None) diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst index f17c6ec..77f4fce 100644 --- a/Doc/whatsnew/3.13.rst +++ b/Doc/whatsnew/3.13.rst @@ -472,6 +472,14 @@ warnings warning may also be emitted when a decorated function or class is used at runtime. See :pep:`702`. (Contributed by Jelle Zijlstra in :gh:`104003`.) +xml.etree.ElementTree +--------------------- + +* Add the :meth:`!close` method for the iterator returned by + :func:`~xml.etree.ElementTree.iterparse` for explicit cleaning up. + (Contributed by Serhiy Storchaka in :gh:`69893`.) + + Optimizations ============= diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py index 221545b..a435ec7 100644 --- a/Lib/test/test_xml_etree.py +++ b/Lib/test/test_xml_etree.py @@ -555,6 +555,17 @@ class ElementTreeTest(unittest.TestCase): ('end', '{namespace}root'), ]) + with open(SIMPLE_XMLFILE, 'rb') as source: + context = iterparse(source) + action, elem = next(context) + self.assertEqual((action, elem.tag), ('end', 'element')) + self.assertEqual([(action, elem.tag) for action, elem in context], [ + ('end', 'element'), + ('end', 'empty-element'), + ('end', 'root'), + ]) + self.assertEqual(context.root.tag, 'root') + events = () context = iterparse(SIMPLE_XMLFILE, events) self.assertEqual([(action, elem.tag) for action, elem in context], []) @@ -646,12 +657,81 @@ class ElementTreeTest(unittest.TestCase): # Not exhausting the iterator still closes the resource (bpo-43292) with warnings_helper.check_no_resource_warning(self): - it = iterparse(TESTFN) + it = iterparse(SIMPLE_XMLFILE) del it + with warnings_helper.check_no_resource_warning(self): + it = iterparse(SIMPLE_XMLFILE) + it.close() + del it + + with warnings_helper.check_no_resource_warning(self): + it = iterparse(SIMPLE_XMLFILE) + action, elem = next(it) + self.assertEqual((action, elem.tag), ('end', 'element')) + del it, elem + + with warnings_helper.check_no_resource_warning(self): + it = iterparse(SIMPLE_XMLFILE) + action, elem = next(it) + it.close() + self.assertEqual((action, elem.tag), ('end', 'element')) + del it, elem + with self.assertRaises(FileNotFoundError): iterparse("nonexistent") + def test_iterparse_close(self): + iterparse = ET.iterparse + + it = iterparse(SIMPLE_XMLFILE) + it.close() + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + + with open(SIMPLE_XMLFILE, 'rb') as source: + it = iterparse(source) + it.close() + self.assertFalse(source.closed) + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + + it = iterparse(SIMPLE_XMLFILE) + action, elem = next(it) + self.assertEqual((action, elem.tag), ('end', 'element')) + it.close() + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + + with open(SIMPLE_XMLFILE, 'rb') as source: + it = iterparse(source) + action, elem = next(it) + self.assertEqual((action, elem.tag), ('end', 'element')) + it.close() + self.assertFalse(source.closed) + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + + it = iterparse(SIMPLE_XMLFILE) + list(it) + it.close() + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + + with open(SIMPLE_XMLFILE, 'rb') as source: + it = iterparse(source) + list(it) + it.close() + self.assertFalse(source.closed) + with self.assertRaises(StopIteration): + next(it) + it.close() # idempotent + def test_writefile(self): elem = ET.Element("tag") elem.text = "text" @@ -3044,8 +3124,7 @@ class ElementIterTest(unittest.TestCase): # With an explicit parser too (issue #9708) sourcefile = serialize(doc, to_string=False) parser = ET.XMLParser(target=ET.TreeBuilder()) - self.assertEqual(next(ET.iterparse(sourcefile, parser=parser))[0], - 'end') + self.assertEqual(next(ET.iterparse(sourcefile, parser=parser))[0], 'end') tree = ET.ElementTree(None) self.assertRaises(AttributeError, tree.iter) diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py index bb7362d..a37fead 100644 --- a/Lib/xml/etree/ElementTree.py +++ b/Lib/xml/etree/ElementTree.py @@ -1248,10 +1248,17 @@ def iterparse(source, events=None, parser=None): if close_source: source.close() + gen = iterator(source) class IterParseIterator(collections.abc.Iterator): - __next__ = iterator(source).__next__ + __next__ = gen.__next__ + def close(self): + if close_source: + source.close() + gen.close() def __del__(self): + # TODO: Emit a ResourceWarning if it was not explicitly closed. + # (When the close() method will be supported in all maintained Python versions.) if close_source: source.close() diff --git a/Misc/NEWS.d/next/Library/2024-01-24-17-25-18.gh-issue-69893.PQq5fR.rst b/Misc/NEWS.d/next/Library/2024-01-24-17-25-18.gh-issue-69893.PQq5fR.rst new file mode 100644 index 0000000..1ebf434 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-01-24-17-25-18.gh-issue-69893.PQq5fR.rst @@ -0,0 +1,2 @@ +Add the :meth:`!close` method for the iterator returned by +:func:`xml.etree.ElementTree.iterparse`. -- cgit v0.12