Why can't Python parse this JSON data? Why can't Python parse this JSON data? python python

Why can't Python parse this JSON data?


Your data is not valid JSON format. You have [] when you should have {}:

  • [] are for JSON arrays, which are called list in Python
  • {} are for JSON objects, which are called dict in Python

Here's how your JSON file should look:

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

Then you can use your code:

import jsonfrom pprint import pprintwith open('data.json') as f:    data = json.load(f)pprint(data)

With data, you can now also find values like so:

data["maps"][0]["id"]data["masks"]["id"]data["om_points"]

Try those out and see if it starts to make sense.


Your data.json should look like this:

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

Your code should be:

import jsonfrom pprint import pprintwith open('data.json') as data_file:        data = json.load(data_file)pprint(data)

Note that this only works in Python 2.6 and up, as it depends upon the with-statement. In Python 2.5 use from __future__ import with_statement, in Python <= 2.4, see Justin Peel's answer, which this answer is based upon.

You can now also access single values like this:

data["maps"][0]["id"]  # will return 'blabla'data["masks"]["id"]    # will return 'valore'data["om_points"]      # will return 'value'


Justin Peel's answer is really helpful, but if you are using Python 3 reading JSON should be done like this:

with open('data.json', encoding='utf-8') as data_file:    data = json.loads(data_file.read())

Note: use json.loads instead of json.load. In Python 3, json.loads takes a string parameter. json.load takes a file-like object parameter. data_file.read() returns a string object.

To be honest, I don't think it's a problem to load all json data into memory in most cases.I see this in JS, Java, Kotlin, cpp, rust almost every language I use.Consider memory issue like a joke to me :)

On the other hand, I don't think you can parse json without reading all of it.


matomo