def eref(obj, key, is_assoc=None):
if obj is None:<EOL><INDENT>return None<EOL><DEDENT>if isinstance(key, int) or (is_assoc is not None and is_assoc):<EOL><INDENT>return ElemRefArr, get_elem(obj), key<EOL><DEDENT>else:<EOL><INDENT>return ElemRefObj, get_elem(obj), key<EOL><DEDENT>
Returns element reference
:param obj:
:param key:
:param is_assoc:
:return: