[SOLVED] Parsing Json with Python

slimcharles · 03-14-2017, 06:10 PM

Hi I am really new to JSON and Python, here is my dilemma, it's been bugging me for two days.
Here is the sample json that I want to parse.

Code:

{
	"Tag1":"{
"TagX":	[
  {
    "TagA": "A",
    "TagB": 1.6,
    "TagC": 1.4,
    "TagD": 3.5,
    "TagE": "01",
    "TagF": null
  },
  {
    "TagA": "A",
    "TagB": 1.6,
    "TagC": 1.4,
    "TagD": 3.5,
    "TagE": "02",
    "TagF": null
  }
],	
"date": "10.03.2017 21:00:00"
	}"
}

Here is my python code:

Code:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import requests
import json
import urllib2

jaysonData = json.load(urllib2.urlopen('URL'))
print jaysonData["Tag1"]

How can I get values of TagB and TagC?
When I try to access them with

Code:

jaysonData = json.load(urllib2.urlopen('URL'))
print jaysonData["Tag1"]["TagX"]["TagB"]

The output is:

Code:

TypeError: string indices must be integers

dugan · 03-14-2017, 06:24 PM

Quote:

Code:

print jaysonData["Tag1"]

And what does that print out?

Also, what does this print out?

Code:

print jaysonData["Tag1"]["TagX"]

slimcharles · 03-15-2017, 12:29 AM

Code:

print jaysonData["Tag1"]

prints

Code:

{
"TagX":	[
  {
    "TagA": "A",
    "TagB": 1.6,
    "TagC": 1.4,
    "TagD": 3.5,
    "TagE": "01",
    "TagF": null
  },
  {
    "TagA": "A",
    "TagB": 1.6,
    "TagC": 1.4,
    "TagD": 3.5,
    "TagE": "02",
    "TagF": null
  }
],	
"date": "10.03.2017 21:00:00"
	}"

Code:

print jaysonData["Tag1"]["TagX"]

prints

Code:

    print jaysonData["Tag1"]["TagX"]
TypeError: string indices must be integers

sundialsvcs · 03-15-2017, 11:30 AM

There's a good synopsis from StackOverflow ...

Python supplies a module that you can access with, simply, import json. All the dirty-work of dealing with a JSON file has been done for you.

Because JSON, and XML, are fairly-well universal, every language that I know of provides one or more "canned" ways of dealing with these file formats.

Quote:

Actum Ne Agas: "Do Not Do A Thing Already Done."

camp0 · 03-15-2017, 12:09 PM

It looks that you have a list with two elements under TagX

so probably you need to do something like

Code:

print jaysonData["Tag1"]["TagX"][0]["TagC"]

slimcharles · 03-17-2017, 06:20 AM

I asked the same question in stackoverflow.
And This answer solved my problem. For future references I am posting the answer and the link here.
Thanks everyone for their help and time.

http://stackoverflow.com/a/42803904/7672271

Answer:
In the returned JSON, the value of Tag1 is a string, not more JSON. It does appear to be JSON encoded as a string though, so convert that to json once more:

Code:

jaysonData = json.load(urllib2.urlopen('URL'))
tag1JaysonData = json.load(jaysonData['Tag1'])
print tag1JaysonData["TagX"]

Also note that TagX is a list, not a dictionary, so there are multiple TagBs in it:

Code:

print [x['TagB'] for x in tag1JaysonData['TagX']]

dugan · 03-17-2017, 09:04 AM

Quote:

Originally Posted by slimcharles

In the returned JSON, the value of Tag1 is a string, not more JSON.

Okay, I can see that now that it's been pointed out.

From your first post:

Code:

{
	"Tag1":"{

Code:

"date": "10.03.2017 21:00:00"
	}"

Pasting it into jsonlint.com actually produces a "parse error".

If you have control over the JSON, then you can fix it:

Code:

{
	"Tag1": {
		"TagX": [{
			"TagA": "A",
			"TagB": 1.6,
			"TagC": 1.4,
			"TagD": 3.5,
			"TagE": "01",
			"TagF": null
		}, {
			"TagA": "A",
			"TagB": 1.6,
			"TagC": 1.4,
			"TagD": 3.5,
			"TagE": "02",
			"TagF": null
		}],
		"date": "10.03.2017 21:00:00"
	}
}

I see in your comments that you don't have control over the data returned. Which makes me wonder (as the SO commenters did) which service is returning this bad JSON.