Pass json string to argument parser python

Question

try to pass json string --model-config {'campaign_id':100500,'run_id':1} to parser:

parser = ArgumentParser(description="")
parser.add_argument(
    '--model-config',
    type=str,
    help='valid json string to set up model config'
)

But in this case I can't use spaces between property names and between key value pairs, otherwise I get an error: unrecognized arguments: 'run_id':1} Also I need to use double quotes (instead of single quotes) for property names. But when I use double quotes I also get an error. Do we have more convenient way to process json string?

Answer 1

Since JSON requires double quotes for string, wrap your option inside a single quote then pass the keys with double quotes. like:

'{"campaign_id":100500, "run_id":1}'

then your full command will be:

python yourfile.py --model-config '{"campaign_id":100500, "run_id":1}'

The option is in a valid format for JSON and can be deserialized with json.loads.

It is possible to use double quotes for the wrapper, but you need to escape the inside double quotes like:

"{\"campaign_id\":100500, \"run_id\":1}"

So I think first one is more convenient.