import json


class JsonDictWithDuplicateKeys(dict):
    """A specialized JSON dict with duplicate keys support.

    """

    def __init__(self, items):
        # `json.dumps()` will check the underlying dict (`self` in our case) and outputs
        # directly if it is empty. So we need to have something in the dictionary.
        self[''] = ''
        self._items = items

    def items(self):
        return self._items


b = '{"dps":{"1630064726":5.0,"1630064726":3.0,"1630064726":6.0}}'
j = json.loads(b, object_pairs_hook=JsonDictWithDuplicateKeys)
print(json.dumps(j, indent=4, sort_keys=True))