Selecting fields from JSON output

Question

Using Python, how can i extract the field id to a variable? Basicaly, i to transform this:

{
    "accountWide": true,
    "criteria": [
        {
            "description": "some description",
            "id": 7553,
            "max": 1,
            "orderIndex": 0
        }
     ]
}

to something like

print "Description is: " + description
print "ID is: " + id
print "Max value is : " + max

Answer 1

Assume you stored that dictionary in a variable called values. To get id in to a variable, do:

idValue = values['criteria'][0]['id']

If that json is in a file, do the following to load it:

import json
jsonFile = open('your_filename.json', 'r')
values = json.load(jsonFile)
jsonFile.close()

If that json is from a URL, do the following to load it:

import urllib, json
f = urllib.urlopen("http://domain/path/jsonPage")
values = json.load(f)
f.close()

To print ALL of the criteria, you could:

for criteria in values['criteria']:
    for key, value in criteria.iteritems():
        print key, 'is:', value
    print ''

Answer 2

Assuming you are dealing with a JSON-string in the input, you can parse it using the json package, see the documentation.

In the specific example you posted you would need

x = json.loads("""{
 "accountWide": true,
 "criteria": [
     {
         "description": "some description",
         "id": 7553,
         "max": 1,
         "orderIndex": 0
     }
  ]
 }""")
description = x['criteria'][0]['description']
id = x['criteria'][0]['id']
max = x['criteria'][0]['max']