这两个函数联合起来用在接口返回 json 数据上非常好使。

lang:pythonimport datetimefrom copy import deepcopydef model2dict(model, datetime_format='%Y-%m-%d %H:%M:%S'):    """    本函数用于使对象可 json 序列化，且返回的字典都是新的（deepcopy）    """    if isinstance(model, dict):        model = Storage(deepcopy(model))        to_pop = []        for k in model:            # 过滤            if isinstance(k, basestring) and (k.startswith('_') or k.isupper()):                to_pop.append(k)                continue            # 转换            elif isinstance(model[k], datetime.datetime):                model[k] = model[k].strftime(datetime_format)            # 递归            else:                model[k] = model2dict(model[k], datetime_format)        for k in to_pop:            model.pop(k)        return model    elif hasattr(model, '__dict__'):        return model2dict(model.__dict__, datetime_format)    elif isinstance(model, (list, tuple)):        return [model2dict(m, datetime_format) for m in model]    else:        return modeldef dict_project(data, map_rulls={}):    """    字典投影，支持取 data 的子集和改名。只想投影而不想改名的，写个 1 就行，eg：        >>> data        {'a': 1,         'b': 2,         'c': 3}        >>> map_rulls        {'a': 'x',         'c': 1}        >>> dict_project(data, map_rulls)        {'x': 1,         'c': 3}    """    if isinstance(data, dict):        data = Storage({map_rulls[k] if isinstance(map_rulls[k], basestring) else k: data[k] for k in data if k in map_rulls})    elif isinstance(data, (list, tuple)):        return [dict_project(o) for o in data]    else:        raise ValueError('无法处理对象: %s' % str(data))    return data

Storage 参见上一篇