python - lxml.etree.iterparse 关闭输入文件处理程序？

Question

过滤器是 using iterparse 解析一个简单的 XML StringIO object在unit test .但是，当之后尝试访问 StringIO 对象时，Python 会退出并显示“ValueError: I/O operation on closed file”消息。根据iterparse documentation ，“从 lxml 2.3 开始，在错误情况下也会调用 .close() 方法，”但是我没有从 iterparse 收到错误消息或 Exception。我的 IO-foo 显然跟不上速度，所以有人有建议吗？

命令和(希望)相关代码:

$ python2.6 setup.py test

设置.py:

from setuptools import setup
from filterous import filterous as package

setup(
    ...
    test_suite = 'tests.tests',

测试/测试.py:

from cStringIO import StringIO
import unittest

from filterous import filterous

XML = '''<posts tag="" total="3" ...'''

class TestSearch(unittest.TestCase):
    def setUp(self):
        self.xml = StringIO(XML)
        self.result = StringIO()
    ...
    def test_empty_tag_not(self):
        """Empty tag; should get N results."""
        filterous.search(
            self.xml,
            self.result,
            {'ntag': [u'']},
            ['href'],
            False)
        self.assertEqual(
            len(self.result.getvalue().splitlines()),
            self.xml.getvalue().count('<post '))

filterous/filterous.py:

from lxml import etree
...
def search(file_pointer, out, terms, includes, human_readable = True):
    ...
    context = etree.iterparse(file_pointer, tag='posts')

回溯:

ERROR: Empty tag; should get N results.
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/victor/dev/filterous/tests/tests.py", line 149, in test_empty_tag_not
    self.xml.getvalue().count('<post '))
ValueError: I/O operation on closed file

PS:所有测试都在 2010-07-27 上运行良好.

Answer 1

似乎可以与 StringIO 配合使用，请尝试使用它代替 cStringIO。不知道为什么要关闭。