Question 202964 in Json Question posted in
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Edit Nested JSON Keys in Python

I have a json object like so

{
    "scenefile": {
        "globaldata": {
            "diffusecoeff": {
                "v": "0.5"
            },
            "specularcoeff": {
                "v": "0.5"
            },
            "ambientcoeff": {
                "v": "0.5"
            }
        },
        "cameradata": { ... },
        "lightdata": [ 
            {"light1": 
                {"strength": {"value": 5}}   
            },
            {"light2": 
                {"strength": {"value": 10}}   
            }
        ]
    }
}

My issue is that I want to get rid of the "v" keys. So it would become

{
    "scenefile": {
        "globaldata": {
            "diffusecoeff": "0.5",
            "specularcoeff": "0.5",
            "ambientcoeff": "0.5"
        },

        "cameradata": {
            ...
        },
        "lightdata": [
            {"light1": {"strength": 5}},
            {"light2": {"strength": 10}}
        ]
    }
}

What is stumping me is that there are several cases of

"attribute": {
    "v": someValue
 }

All throughout the nested json file (not just in the format mentioned above), and so I am looking for a way to quickly change all of those to just be

"attribute": someValue
Tags:

2

Answers


  1. 0

    Just loop over the elements of that one dictionary, replacing each value with the nested v key’s value.

    data = {
    "scenefile": {
        "globaldata": {
            "diffusecoeff": {
                "v": "0.5"
            },
            "specularcoeff": {
                "v": "0.5"
            },
            "ambientcoeff": {
                "v": "0.5"
            }
        },
        "cameradata": { ... },
        "lightdata": [ ... ]
    }
}

globaldata = data['scenefile']['globaldata']
for key, value in globaldata.items():
    globaldata[key] = value['v']

pprint.pprint(data)

    Output:

    {'scenefile': {'cameradata': {Ellipsis},
               'globaldata': {'ambientcoeff': '0.5',
                              'diffusecoeff': '0.5',
                              'specularcoeff': '0.5'},
               'lightdata': [Ellipsis]}}

    This doesn’t touch the rest of the dictionary, so other v keys are left alone.

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  2. 0

    Use a recursive function.

    If the parameter is a dictionary, loop over its elements. If any of them is a dictionary with just one element, and the key begins with v, replace the dictionary with the nested value. Otherwise, recurse into the value.

    If the parameter is a list, iterate over its elements and recurse into each element.

    def replace_values_recursive(data):
    if isinstance(data, dict):
        for key, value in data.items():
            if isinstance(value, dict) and len(value) == 1 and next(iter(value)).startswith('v'):
                data[key] = next(iter(value.values()))
            else:
                replace_values_recursive(value)
    elif isinstance(data, list):
        for value in data:
            replace_values_recursive(value)
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