Python related

ElementTree_xml_cache_oddness.py

# ElementTree XML API _cache test
# Matt Maybeno 2015

import unittest
import xml.etree.ElementTree as ET


class TestElementTreeXml(unittest.TestCase):

    def setUp(self):
        self.xml1 = """<?xml version="1.0"?>
        <actors xmlns:fictional="http://characters.example.com"
                xmlns="http://people.example.com">
          <actor>
            <name>John Cleese</name>
            <fictional:character>Lancelot</fictional:character>
            <fictional:character>Archie Leach</fictional:character>
          </actor>
          <actor>
            <name>Eric Idle</name>
            <fictional:character>Sir Robin</fictional:character>
            <fictional:character>Gunther</fictional:character>
            <fictional:character>Commander Clement</fictional:character>
          </actor>
        </actors>
        """
        self.ns1 = {'real_person': 'http://people.example.com',
                    'role': 'http://characters.example.com'}

        self.xml2 = """<?xml version="1.0"?>
        <actors xmlns:fictional="http://characters.example_2.com"
                xmlns="http://people.example_2.com">
          <actor>
            <name>John Cleese</name>
            <fictional:character>Lancelot</fictional:character>
            <fictional:character>Archie Leach</fictional:character>
          </actor>
          <actor>
            <name>Eric Idle</name>
            <fictional:character>Sir Robin</fictional:character>
            <fictional:character>Gunther</fictional:character>
            <fictional:character>Commander Clement</fictional:character>
          </actor>
        </actors>
        """
        self.ns2 = {'real_person': 'http://people.example_2.com',
                    'role': 'http://characters.example_2.com'}

        # Pre find element to build ElementPath _cache
        eltree = ET.fromstring(self.xml1)
        eltree.find('.real_person:actor', self.ns1)

    def test_xml_ns1(self):
        """
        Finds the xml element using the namespace from the ns1 dictionary.
        This works because it is using the existing _cache from the
        namespace
        """

        eltree1 = ET.fromstring(self.xml1)
        self.assertIsNotNone(eltree1.find('.real_person:actor', self.ns1))

    def test_xml_ns2(self):
        """
        Attempts to find the xml element using the namespace from the
        ns2 dictionary but fails because ns1 is already placed in
        ElementPath _cache using the same dict keys.

        https://hg.python.org/cpython/file/2.7/Lib/xml/etree/ElementPath.py#l235
        """

        eltree2 = ET.fromstring(self.xml2)
        # This should not return None I believe
        self.assertIsNone(eltree2.find('.real_person:actor', self.ns2))

        # Manually clear cache from the ElementPath module
        ET.ElementPath._cache.clear()
        self.assertIsNotNone(eltree2.find('.real_person:actor', self.ns2))


if __name__ == '__main__':
    unittest.main()

given this bug report: http://bugs.python.org/issue17011, the issue is fixed in python > 3.3 and the test breaks when running it.