Why Does My JSON Decoder Fail: Incorrect Syntax in Arrays vs. Objects?

Why JSON Decode Fails: Invalid Syntax

The provided JSON data exhibits an error that prevents Python from parsing it successfully. The root cause lies in the incorrect syntax of the "masks" and "parameters" elements.

Syntax of JSON Objects vs. Arrays

JSON objects, which are equivalent to dictionaries in Python, are enclosed in curly braces {}. Arrays, represented as lists in Python, are enclosed in square brackets [].

Error in the JSON Data

The given JSON data incorrectly uses [] instead of {} for "masks" and "parameters." This syntax error results in the error message:

json.decoder.JSONDecodeError: Expecting ',' delimiter: line 13 column 13 (char 213)

Correcting the JSON Syntax

To fix the syntax error, the brackets surrounding "masks" and "parameters" should be replaced with curly braces. The corrected JSON data should look like this:

{
    "maps": [
        {
            "id": "blabla",
            "iscategorical": "0"
        },
        {
            "id": "blabla",
            "iscategorical": "0"
        }
    ],
    "masks": {
        "id": "valore"
    },
    "om_points": "value",
    "parameters": {
        "id": "valore"
    }
}

Python Code for Parsing Valid JSON

Once the JSON data is corrected, the Python code can successfully parse it using the json.load() method. The code provided can be used as follows:

import json
from pprint import pprint

with open('data_fixed.json') as f:
    data = json.load(f)

pprint(data)

This code will print the contents of the JSON data in a readable format using the pprint() function.

Extracting Values from JSON

After parsing the JSON data, individual values can be accessed using Python dictionaries and list syntax. For example:

• data['maps'][0]['id']
• data['masks']['id']
• data['om_points']

The above is the detailed content of Why Does My JSON Decoder Fail: Incorrect Syntax in Arrays vs. Objects?. For more information, please follow other related articles on the PHP Chinese website!