xml_etree_elementtree.py 文件源码

def is_available(cls):
        # Is vital piece of ElementTree module available at all?
        try:
            cls.ET.Element
        except:
            return False
        # We only support ElementTree version 1.3+
        from distutils.version import StrictVersion
        return StrictVersion(BaseET.VERSION) >= StrictVersion('1.3')