json.loads allows duplicate keys in a dictionary, overwriting the first value

Question

>>> raw_post_data = request.raw_post_data
>>> print raw_post_data
{\"group\":{\"groupId\":\"2\", \"groupName\":\"GroupName\"}, \"members\":{\"1\":{         


        

Answer 1

One alternative I wrote based on the solution posted by other users of this question is to convert those duplicates into an array:

def array_on_duplicate_keys(ordered_pairs):
    """Convert duplicate keys to arrays."""
    d = {}
    for k, v in ordered_pairs:
        if k in d:
            if type(d[k]) is list:
                d[k].append(v)
            else:
                d[k] = [d[k],v]
        else:
           d[k] = v
    return d

And then:

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

gives you the output:

{'x': [1, 2]}

Later one, one can check easily how meany duplicates an entry has by using:

if type(dict['x']) is list:
    print('Non-unique entry in dict at x, found', len(dict['x']),'repetitions.')