从嵌套字典中的特定对象获取所有信息

Question

我试图通过查看特定键从嵌套字典中获取一组数据。你知道吗

我的嵌套词典如下所示：

dict_items = {
    "base_id": {
        "some-id-C03": {
            "index": 3, 
            "role": "admin", 
            "text": "test_A_02", 
            "data": {
                "comment": "A test", 
                "version": "1", 
                "created": "05/09/18 14:18", 
                "created_by": "John"
            }, 
            "type": "subTesting", 
        }, 
        "some-id-B01": {
            "index": 1, 
            "role": "admin", 
            "text": "test_B_02", 
            "data": {
                "comment": "B test",
                "version": "1", 
                "created": "05/09/18 14:16", 
                "created_by": "Pete"
            }, 
            "type": "subTesting", 
            "id": "33441122-b655-8877-ccddeeff88bb"
        },
        "some-id-A03": {
            "index": 1, 
            "role": "admin", 
            "text": "test_C_01", 
            "data": {
                "comment": "C test",
                "version": "1", 
                "created": "15/06/18 09:12", 
                "created_by": "Pete"
            }, 
            "type": "subTesting", 
            "id": "55667788-c122-8877-zzddff00bb11"
        }
    }
}

而我可以使用以下方法执行：

for item in dict_items.get('base_id').values():
    print item['data']['created_date']

如何判断/附加属于我所查询的created_date中的其他信息？你知道吗

例如，我想获取最新的2个信息（使用datetime模块），在本例中，它将返回属于键some-id-C03和some-id-B01的所有信息

这是我期望的输出：

"some-id-C03": {
    "index": 3, 
    "role": "admin", 
    "text": "test_A_02", 
    "data": {
        "comment": "A test", 
        "version": "1", 
        "created": "05/09/18 14:18", 
        "created_by": "John"
    }, 
    "type": "subTesting", 
}, 
"some-id-B01": {
    "index": 1, 
    "role": "admin", 
    "text": "test_B_02", 
    "data": {
        "comment": "B test",
        "version": "1", 
        "created": "05/09/18 14:16", 
        "created_by": "Pete"
    }, 
    "type": "subTesting", 
    "id": "33441122-b655-8877-ccddeeff88bb"
}

Answer 1

如果我理解正确，您希望能够查询此数据结构，以便最终得到与某些条件匹配的所有条目。你知道吗

我会这样设置：

def query_dict_items(data_dict, condition_fn):
    '''
    Return a list containing the contents of `data_dict` for which 
    `condition_fn` returns `True`.
    '''

    results = []
    for data_item in data_dict['base_id'].values():
        if condition_fn(data_item):
            results.append(data_item)

    return results

然后你可以定义你想要的任何条件。检索在特定日期创建的所有项的示例：

from datetime import datetime

#   Define a condition function that matches items from Sept 5th, 2018.
sept_5 = datetime.strptime('05/09/18', '%d/%m/%y')
def was_on_sept_5(data_item):
    date_str = data_item['data']['created'].split(' ')[0]
    return datetime.strptime(date_str, '%d/%m/%y').date() == sept_5.date()

#   Print the resulting list.
from pprint import pprint
pprint(query_dict_items(dict_items, was_on_sept_5))

希望这能让你朝着正确的方向前进。你知道吗