code: def parse(xmlfile, element_names, element_attrs={}, attr_conversions={},
            heterogeneous=False, warn=False):
      
      if isinstance(element_names, str):
          element_names = [element_names]
      elementTypes = {}
      for event, parsenode in ET.iterparse(xmlfile):
          if parsenode.tag in element_names:
              yield _get_compound_object(parsenode, elementTypes,
                                         parsenode.tag, element_attrs,
                                         attr_conversions, heterogeneous, warn)
              parsenode.clear()
docs: Parses the given element_names from xmlfile and yield compound objects for
      their xml subtrees (no extra objects are returned if element_names appear in
      the subtree) The compound objects provide all element attributes of
      the root of the subtree as attributes unless attr_names are supplied. In this
      case attr_names maps element names to a list of attributes which are
      supplied. If attr_conversions is not empty it must map attribute names to
      callables which will be called upon the attribute value before storing under
      the attribute name.
      The compound objects gives dictionary style access to list of compound
      objects o for any children with the given element name
      o['child_element_name'] = [osub0, osub1, ...]
      As a shorthand, attribute style access to the list of child elements is
      provided unless an attribute with the same name as the child elements
      exists (i.e. o.child_element_name = [osub0, osub1, ...])
      @Note: All elements with the same name must have the same type regardless of
      the subtree in which they occur (heterogeneous cases may be handled by
      setting heterogeneous=False (with reduced parsing speed)
      @Note: Attribute names may be modified to avoid name clashes
      with python keywords. (set warn=True to receive renaming warnings)
      @Note: The element_names may be either a single string or a list of strings.
      @Example: parse('plain.edg.xml', ['edge'])