python - type=dict in argparse.add_argument()

Question

I'm trying to set up a dictionary as optional argument (using argparse); the following line is what I have so far:

parser.add_argument('-i','--image', type=dict, help='Generate an image map from the input file (syntax: {'name': <name>, 'voids': '#08080808', '0': '#00ff00ff', '100%%': '#ff00ff00'}).')

But running the script:

 $ ./script.py -i {'name': 'img.png','voids': '#00ff00ff','0': '#ff00ff00','100%': '#f80654ff'}

script.py: error: argument -i/--image: invalid dict value: '{name:'

Even though, inside the interpreter,

>>> a={'name': 'img.png','voids': '#00ff00ff','0': '#ff00ff00','100%': '#f80654ff'}

works just fine.

So how should I pass the argument instead? Thanks in advance.

Answer 1

Necroing this: json.loads works here, too. It doesn't seem too dirty.

import json
import argparse

test = '{"name": "img.png","voids": "#00ff00ff","0": "#ff00ff00","100%": "#f80654ff"}'

parser = argparse.ArgumentParser()
parser.add_argument('-i', '--input', type=json.loads)

args = parser.parse_args(['-i', test])

print(args.input)

Returns:

{u'0': u'#ff00ff00', u'100%': u'#f80654ff', u'voids': u'#00ff00ff', u'name': u'img.png'}