python querying a json objectpath

Question

I've a nested json structure, I'm using objectpath (python API version), but I don't understand how to select and filter some information (more precisely the nested information in the structure).

EG. I want to select the "description" of the action "reading" for the user "John".

JSON:

{
    "user": 
    {
            "actions":   
             [
                 {
                 "name": "reading",
                 "description": "blablabla"
                 }
             ]
            "name": "John"
    }
}

CODE:

$.user[@.name is 'John' and @.actions.name is 'reading'].actions.description

but it doesn't work (empty set but in my JSON it isn't so). Any suggestion?

@PepperoniPizza: Yeah, he has a name: value inside an array. — abarnert
– abarnert, Commented May 2, 2015 at 0:26
Why is this tagged python? You're asking how to use some JavaScript library in JavaScript to parse some JSON. — abarnert
– abarnert, Commented May 2, 2015 at 0:27
I'm using the python version of the library and it has some features that the javascript version don't have. — Chris Cris
– Chris Cris, Commented May 2, 2015 at 12:33
There's a group where you can ask Qs about ObjectPath if something doesn't work as expected groups.google.com/forum/#!forum/objectpath — Ela Bednarek
– Ela Bednarek, Commented Oct 6, 2015 at 20:56

user3657941 · Accepted Answer · 2016-08-18 20:35:14Z

7

Is this what you are trying to do?

import objectpath

data = {
    "user": {
        "actions": {
                "name": "reading",
                "description": "blablabla"
            },
        "name": "John"
    }
}

tree = objectpath.Tree(data)
result = tree.execute("$.user[@.name is 'John'].actions[@.name is 'reading'].description")
for entry in result:
    print entry

Output

blablabla

I had to fix your JSON. Also, tree.execute returns a generator. You could replace the for loop with print result.next(), but the for loop seemed more clear.

answered Aug 18, 2016 at 20:35

user3657941

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Comments

fndg87 · Accepted Answer · 2016-08-18 19:56:20Z

1

import objectpath import *

your_json = {"name": "felix", "last_name": "diaz"}

# This json path will bring all the key-values of your json

your_json_path='$.*'

my_key_values = Tree(your_json).execute(your_json_path)

# If you want to retrieve the name node...then specify it. 
my_name= Tree(your_json).execute('$.name')

# If you want to retrieve a the last_name node...then specify it. 
last_name= Tree(your_json).execute('$.last_name')

edited Aug 18, 2016 at 19:56

answered Aug 18, 2016 at 19:19

fndg87

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2 Comments

Shawn Over a year ago

Please include some explanation to make the example easier to understand. :-)

user3657941 Over a year ago

This does not answer the question and is even more confusing than the documentation (which is some of the worst I have ever seen).

admarple · Accepted Answer · 2019-06-03 04:43:28Z

I believe you're just missing a comma in JSON:

{
    "user": 
    {
        "actions": [
            {
                 "name": "reading",
                 "description": "blablabla"
            }
        ],
        "name": "John"
    }
}

Assuming there is only one "John", with only one "reading" activity, the following query works:

$.user[@.name is 'John'].actions[0][@.name is 'reading'][0].description

If there could be multiple "John"s, with multiple "reading" activities, the following query will almost work:

$.user.*[@.name is 'John'].actions..*[@.name is 'reading'].description

I say almost because the use of .. will be problematic if there are other nested dictionaries with "name" and "description" entries, such as

{
    "user": {
        "actions": [
            {
                "name": "reading",
                "description": "blablabla",
                "nested": {
                    "name": "reading",
                    "description": "broken"
                }
            }
        ],
        "name": "John"
    }
}

To get a correct query, there is an open issue to correctly implement queries into arrays: https://github.com/adriank/ObjectPath/issues/60

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