pi@retropie:~ $ python export.py -d /home/pi/RetroPie/roms/export_list.xlsx
2018-02-18 19:34:51,258 DEBUG  Starting
2018-02-18 19:34:51,258 INFO   Emulationstation systems file used: /etc/emulationstation/es_systems.cfg
2018-02-18 19:34:51,279 DEBUG  Analyzing system: Amstrad CPC (amstradcpc)
2018-02-18 19:34:51,279 DEBUG  Amstrad CPC system has no gamelist, skipping
2018-02-18 19:34:51,280 DEBUG  Analyzing system: Arcade (arcade)
2018-02-18 19:34:51,281 DEBUG  Arcade system has no gamelist, skipping
2018-02-18 19:34:51,281 DEBUG  Analyzing system: Atari 2600 (atari2600)
Traceback (most recent call last):
  File "export.py", line 460, in <module>
    systems = parse_systems()
  File "export.py", line 241, in parse_systems
    rom = Game(game)
  File "export.py", line 146, in __init__
    self.info[attr] = get_xml_element_date(obj, attr)
  File "export.py", line 69, in get_xml_element_date
    if len(date_text) < len('19860101T000000'):
TypeError: object of type 'NoneType' has no len()