ElementTree.py 文件源码

def _get_py3_cls():
    """Python 3.3 hides the pure Python code but defusedxml requires it.

    The code is based on test.support.import_fresh_module().
    """
    pymodname = "xml.etree.ElementTree"
    cmodname = "_elementtree"

    pymod = sys.modules.pop(pymodname, None)
    cmod = sys.modules.pop(cmodname, None)

    sys.modules[cmodname] = None
    pure_pymod = importlib.import_module(pymodname)
    if cmod is not None:
        sys.modules[cmodname] = cmod
    else:
        sys.modules.pop(cmodname)
    sys.modules[pymodname] = pymod

    _XMLParser = pure_pymod.XMLParser
    _iterparse = pure_pymod.iterparse
    ParseError = pure_pymod.ParseError

    return _XMLParser, _iterparse, ParseError