#!/usr/bin/env python
'''Use etree navigation to extract planets from solar.xml'''
import lxml.etree as ET


def main():
    '''Program entry point'''
    doc = ET.parse('../DATA/solar.xml')  # <1>

    solar_system = doc.getroot()  # <2>

    print(solar_system)
    print()

    inner = solar_system.find('innerplanets')  # <3>
    print('Inner:')

    for planet in inner:  # <4>
        if planet.tag == 'planet':
            print('\t', planet.get("planetname", "NO NAME"))

    outer = solar_system.find('outerplanets')
    print('Outer:')

    for planet in outer:
        print('\t', planet.get("planetname"))

    plutoids = solar_system.find('dwarfplanets')
    print('Dwarf:')

    for planet in plutoids:
        print('\t', planet.get("planetname"))


if __name__ == '__main__':
    main()