Translate elements in XML and add proper "lang" attribute

translate_xml.py

from lxml import etree
import mtranslate
import copy


def copy_element(element):
    """Copies element usin deepcopy, returns it"""
    result = copy.deepcopy(element)
    return result

def duplicate_element(element):
    """Creates copy of given element within parent,
    changes its """
    parent = element.getparent()
    result = copy_element(element)
    parent.append(result)
    # if result.getparent() != parent:
    return result

def open_file(path):
    parser = etree.XMLParser(strip_cdata=False)
    with open(path, "rb") as source:
        return etree.parse(source, parser=parser)

def write_file(tree, path):
    et = etree.ElementTree(tree)
    et.write(path, pretty_print=True, encoding="utf-8")

def translate_elements(elements):
    for element in elements:
        parent = element.getparent()
        translated_element = duplicate_element(element)
        try:
            translated_text = mtranslate.translate(element.text, "pl")
            translated_element.text = etree.CDATA(translated_text)
        except Exception as e:
            print(e)
        translated_element.attrib['lang'] = 'pl_PL'
        print(translated_element.getparent(), etree.tostring(translated_element))
        print(element.getparent(), etree.tostring(element))

def position_elements(elements):
    for element in elements:
        parent = element.getparent()
        lower_neighbour = parent.find('.//%s[@lang="pt_BR"]' % element.tag)
        try:
            insert_index = parent.index(lower_neighbour)
            parent.insert(insert_index, element)
        except Exception as e:
            print(e)


def main():
    tree = open_file('cpt_org.xml')
    root = tree.getroot()
    translate_elements([child for child in root.findall('.//*[@lang="en_US"]')])
    position_elements([child for child in root.findall('.//*[@lang="pl_PL"]')])
    write_file(root, 'result.xml')

if __name__ == '__main__':
    main()

Example

// TODO