常用单例函数 遍历字典函数

def singleton(cls):
    _instance = {}

    def _singleton(*args, **kwargs):
        if cls not in _instance:
            _instance[cls] = cls(*args, **kwargs)
        return _instance[cls]

    return _singleton


def get_dict(dict1, obj, default=None):
    """ 遍历嵌套字典，得到想要的value
        dict1所需遍历的字典
        obj 所需value的键"""
    for k, v in dict1.items():
        if k == obj:
            return v
        else:
            if type(v) is dict:  # 如果是字典
                re = get_dict(v, obj, default)  # 递归
                if re is not default:
                    return re