What format does data input have to be for Python's json.loads?

Question

I'm trying to use json.loads to parse data in a Redshift database table. I've stripped out the function to test in a Python script and am having trouble understanding what's happening.

The code I'm using is:

import json
j="'['Bars', 'American (Traditional)', 'Nightlife', 'Restaurants']'"

def trythis(item, reverse):
    if not j:
        return '1'
    try:
         arr = json.loads(j)
    except ValueError:
        return '2'
    if not ascending:
        arr = sorted(arr, reverse=True)
    else:
        arr = sorted(arr)
    return json.dumps(arr)

print trythis(j, True)

And this is returning 2.

I've tried changing the input variable to j="['Bars', 'American (Traditional)', 'Nightlife', 'Restaurants']" but that hasn't worked. What format does my entry value need to be?

Answer 1

Your input string j is not valid JSON. JSON doesn't allow the use of single quotes (') to denote string values.

Try switching the quotes: '["Bars", "American (Traditional)", "Nightlife", "Restaurants"]'

The JSON specification is an excellent resource for determining if your input is valid JSON. You can find it here: http://www.json.org/