Aoying error when importing and using JSON string from file

I have a dictionary like so:

{
    'cost' : cost,
    'oLen' : oLen
}

I write this to file so the file contains:

{'oLen': 32, 'cost': 2048}

Later, I do this:

    with open('conf.conf') as f:
        config = json.loads(f.read())
    print config['oLen']

And get this:

ValueError: Expecting property name: line 1 column 2 (char 1)

If I change json.loads to json.dumps, I get:

TypeError: string indices must be integers, not str

You need to use double quotes in your JSON.

If you use json.dump to write the original dictionary to the file, you won't need to worry about it though!

Change your single quotes to double quotes:

{"oLen": 32, "cost": 2048}

JSON is picky about that.

You need to use Double Quotations

{"oLen": 32, "cost": 2048}

JSON example