New to Python and working on it to mess with JSON files

Question

So I'm new to phython, and I was wondering on how I could modify(adding or subtracting) each individual "x" in one go.

            "Position": {
            "7,-5": {
                "id": "58",
                "y": -5,
                "x": 7
            },
            "2,-4": {
                "id": "183",
                "y": -4,
                "x": 2
            },
            "-4,-1": {
                "id": "190",
                "y": -1,
                "x": -4
            }

I tried doing

import json
with open ('position.txt', 'r+') as f:
    position_data = json.load(f)
    position_data['Position']['x'] = +1

 TypeError: list indices must be integers or slices, not str

This is what I want

            "Position": {
            "7,-5": {
                "id": "58",
                "y": -5,
                "x": 8
            },
            "2,-4": {
                "id": "183",
                "y": -4,
                "x": 3
            },
            "-4,-1": {
                "id": "190",
                "y": -1,
                "x": -3
            }

I'm not sure on how to go from here. Please advice.

Answer 1

you could do something like this:

for key in position_data['Position'].keys():
    position_data['Position'][key]['x'] += 1

Answer 2

for value in position_data['Position'].values():
    value['x'] += 1

Use itervalues in Python 2 for better efficiency.

Demo (since I got downvoted without explanation):

from pprint import pprint

position_data = {
    "Position": {
        "7,-5": {
            "id": "58",
            "y": -5,
            "x": 7
        },
        "2,-4": {
            "id": "183",
            "y": -4,
            "x": 2
        },
        "-4,-1": {
            "id": "190",
            "y": -1,
            "x": -4
        }
    }
}

pprint(position_data)

for value in position_data['Position'].values():
    value['x'] += 1

pprint(position_data)

Output:

{'Position': {'-4,-1': {'id': '190', 'x': -4, 'y': -1},
              '2,-4': {'id': '183', 'x': 2, 'y': -4},
              '7,-5': {'id': '58', 'x': 7, 'y': -5}}}
{'Position': {'-4,-1': {'id': '190', 'x': -3, 'y': -1},
              '2,-4': {'id': '183', 'x': 3, 'y': -4},
              '7,-5': {'id': '58', 'x': 8, 'y': -5}}}