for (year, month, day), posts in blog_dict.items():
_new_dict[year, month, day] = _posts = []
for _file, _title, _lead, _tags in posts:
for (year, month, day), posts in blog_dict.items():
_new_dict[year, month, day] = _posts = []
for _file, _title, _lead, _tags in posts: