{'первый элемент':[1,2,3,4,5,6,7,8,9,10], 'второй элемент':[1,2,3,4,5,6,7,8,9,10], ...}
d = {'первый элемент':[1,2,3,4,5,6,7,8,9,10], 'второй элемент':[1,2,3,4,5,6,7,8,9,10], ...}
with open(file_name, 'w') as fh:
fh.write(repr(d))
import json
with open(file_name, 'w') as fh:
fh.write(json.dumps(d, ensure_ascii=False).encode('utf-8'))