使用
collections.defaultdict:
def recursively_default_dict(): return collections.defaultdict(recursively_default_dict)my_dict = recursively_default_dict()my_dict['a']['b'] = 'c'

使用
collections.defaultdict:
def recursively_default_dict(): return collections.defaultdict(recursively_default_dict)my_dict = recursively_default_dict()my_dict['a']['b'] = 'c'