loads允许字典中有重复的键，覆盖第一个值

Question

>>> raw_post_data = request.raw_post_data
>>> print raw_post_data
{"group":{"groupId":"2", "groupName":"GroupName"}, "members":{"1":{"firstName":"fName","lastName":"LName","address":"address"},"1": {"firstName":"f_Name","lastName":"L_Name","address":"_address"}}}
>>> create_request = json.loads(raw_post_data)
>>> print create_request
{u'group': {u'groupName': u'GroupName', u'groupId': u'2'}, u'members': {u'1': {u'lastName': u'L_Name', u'firstName': u'f_Name', u'address': u'_address'}}}

如您所见，当我使用json.dumps()时，键为“1”的成员将被覆盖

有没有办法在python中将其捕获为异常，即在来自客户端的请求中发现重复的密钥？

Answer 1

这是answer by jfs的linter固定和类型注释版本。解决了各种绒布突出的问题。Python 3.6+使用f-strings也使其现代化。

import json
from typing import Any, Dict, Hashable, List, Tuple

def check_for_duplicate_keys(ordered_pairs: List[Tuple[Hashable, Any]]) -> Dict:
    """Raise ValueError if a duplicate key exists in provided ordered list of pairs, otherwise return a dict."""
    dict_out: Dict = {}
    for key, val in ordered_pairs:
        if key in dict_out:
            raise ValueError(f'Duplicate key: {key}')
        else:
            dict_out[key] = val
    return dict_out

json.loads('{"x": 1, "x": 2}', object_pairs_hook=check_for_duplicate_keys)