from lxml import etree as ET
users = ET.Element('users')
user = ET.SubElement(users, 'user')
name = ET.SubElement(user, 'name')
name.text = 'aaa'
age = ET.SubElement(user, 'age')
age.text = '25'
age.attrib['bod'] = '1986.8'
sex = ET.SubElement(user, 'sex')
sex.text = 'a'
print ET.tostring(users, pretty_print=True, xml_declaration=True, encoding='utf-8')
# write to file:
tree = ET.ElementTree(users)
tree.write('users.xml', pretty_print=True, xml_declaration=True, encoding='utf-8')