Python将部分字典复制到新字典中

Question

我有一个看起来像这样的 python 字典:

old_dict={"payment_amt": "20",
          "chk_nr": "321749",
          "clm_list": {"dtl": [{"clm_id": "1A2345", "name": "John"},
                               {"clm_id": "9999", "name": "Jack"}]}}

我需要解析上面的内容并将其存储为:

{"payment_amt": "20",
 "clm_list": {"dtl": [{"clm_id": "1A2345"},
                      {"clm_id": "9999"}]}}

是否有正确的 pythonic 方法来做到这一点？

谢谢

Answer 1

就个人而言，如果输入始终与您列出的完全一样，我会直接复制您想要保留在您发布的示例中的确切键(请参阅 Rob 的回答)。保持简单。

但是，如果您不能依赖输入始终具有完全相同的结构，您仍然可以将其减少为仅包含预期的键，并使用使用字典理解的递归函数。

old_dict = {"payment_amt": "20", 
            "chk_nr": "321749", 
            "clm_list": {"dtl": [{"clm_id": "1A2345", "name": "John"}, 
                                 {"clm_id": "9999", "name": "Jack"}]}}

keep = ["payment_amt", "clm_list", "dtl", "clm_id"]

def recursively_prune_dict_keys(obj, keep):
    if isinstance(obj, dict):
        return {k: recursively_prune_dict_keys(v, keep) for k, v in obj.items() if k in keep}
    elif isinstance(obj, list):
        return [recursively_prune_dict_keys(item, keep) for item in obj]
    else:
        return obj

new_dict = recursively_prune_dict_keys(old_dict, keep)
print new_dict

输出:

{'clm_list': {'dtl': [{'clm_id': '1A2345'}, {'clm_id': '9999'}]}, 'payment_amt': '20'}