Tell me more ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 2 down vote favorite

I have the following JSON string (from wikipedia http://en.wikipedia.org/wiki/JSON)

{
        "name":"Product",
        "properties":
        {
                "id":
                {
                        "type":"number",
                        "description":"Product identifier",
                        "required":true
                },
                "name":
                {
                        "type":"string",
                        "description":"Name of the product",
                        "required":true
                },
                "price":
                {
                        "type":"number",
                        "minimum":0,
                        "required":true
                },
                "tags":
                {
                        "type":"array",
                        "items":
                        {
                                "type":"string"
                        }
                },
                "stock":
                {
                        "type":"object",
                        "properties":
                        {
                                "warehouse":
                                {
                                        "type":"number"
                                },
                                "retail":
                                {
                                        "type":"number"
                                }
                        }
                }
        }
}

I am trying to decode this string using Python json library. I would like to access the node

properties - > stock - > properties - > warehouse.

I understand that json.loads() function stores the json string as a dictionary. But in this case properties is my key and everything under that are values. How do I access the above node. 

import json
jsonText=""
file = open("c:/dir/jsondec.json")
for line in file.xreadlines():
    jsonText+=line
data = json.loads(jsonText)
for k,v in data.items():
    print k // shows name and properties
file.close();

Thanks

share|improve this question
Are you aware of json.load()? – Wooble Jun 20 '12 at 19:39

1 Answer

up vote 6 down vote accepted

You can load json straight from the file like this:

 f = open("c:/dir/jsondec.json")
 data = json.load(f)

Based on your input string, data is now a dictionary that contains other dictionaries. You can just navigate up the dictionaries like so:

 node = data['properties']['stock']['properties']['warehouse']
 print str(node)
share|improve this answer
Oh I understand . Thanks.. Then whats the use of loads . I'll read the doc.. – Ankur Jun 20 '12 at 19:42
3  
@Ankur sometimes your json won't come from a file - that's when you use loads. – Steve Mayne Jun 20 '12 at 19:44
Thanks.. In works for this json but in other json I get TypeError: list indices must be integers, not str. Can you guess why – Ankur Jun 20 '12 at 20:10
The data structure you get back will entirely depend on the json you put in - the elements of your dictionaries might be scalar types, lists or dictionaries. If you have more generic iteration requirements, it might be worth editing your question. – Steve Mayne Jun 20 '12 at 20:17

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.