Convert pseudo Json string into a Python object

Question

I have a string that looks like JSON but it's not. I want to convert it into a Python object (back and forth).

Here is the format:

v = "{ TestKey = true,
Calibration = 0,
Blacks = 0,
Brightness = 50,
BasicSetting = { 0,
0,
32,
22},
Whites = 0 }"

I can not use directly json.load(v) on such string. What's the best / easiest way to convert it into a Python object ? Writing a custom Python JSON encoder / decoder ? I will need to decode the Python back into the original string format.

So far, I'm replacing = by : but I face some issues to correctly put the ' in the original string and I don't think it's the best way to do. Any other suggestions ?

Thanks.

What have you tried so far? SO is not a code factory. If you want our help you have to show some effort. — zero323
– zero323, Commented Nov 1, 2013 at 11:02
So far, pattern substitution but it's kind of a hack, I'm sure there is a better way to do it. — user2944669
– user2944669, Commented Nov 1, 2013 at 11:06
"I will need to decode the Python back into the original string format" -- in this case, you probably want to write a custom json encode/decoder — shx2
– shx2, Commented Nov 1, 2013 at 11:07
This looks sufficiently different from JSON that you won't have much success with any JSON parser, custom or not. In particular, {0,0,32,22} appears to be intended as an array, but it starts with the same delimiter as a dictionary and the only way to distinguish it from a dictionary is to look ahead (indefinitely) and see that there's no = value part (this is in start contrast to JSON, where you can distinguish arrays and dicts by their starting delimiter). Where is this stupid data format from? — user395760
– user395760, Commented Nov 1, 2013 at 11:08
It is ugly but seems to work import json; import re; v1 = re.sub(r'([a-zA-Z]+)', r'"\g<1>"', v.replace('=', ':').replace("\n", "")); json.loads(re.sub(r"{([^:]+)}", "[\g<1>]", v1)); — zero323
– zero323, Commented Nov 1, 2013 at 11:27

zero323 · Accepted Answer · 2013-11-01 19:48:15Z

1

It is ugly as hell and some regex ninja would be able to achieve this using half of the symbols but seems to work:

import json
import re

def parse(v):
    # Remove newlines and replace "=" with ":"
    v1 =  v.replace('=', ':').replace("\n", "")
    # Enclose strings in double quotes
    v2 = re.sub(r'(\d*[a-zA-Z][a-zA-Z0-9]*)', r'"\g<1>"', v1)
    # If you want booleans
    v3 = re.sub(r'"(true|false)"', r'\g<1>', v2)
    # Create lists
    return json.loads(re.sub(r"{([^:]+)}", r'[\g<1>]', v3))

edited Nov 1, 2013 at 19:48

answered Nov 1, 2013 at 11:57

zero323

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user2944669 Over a year ago

Thanks ! I have still kept my automaton because the value could also have some " like "here is my text" so I ended-up with some issues with the regexp. Thanks again for having taken time to provide a solution.

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