An action implementing key=<json> parsing

keyvaluejsonaction.py

import argparse
import json

class KeyValueJsonAction(argparse.Action):
    """
    Argparse action for generating dictionaries from key-value args with JSON support
    """
    def __call__(self, parser, namespace, values, option_string=None):
        result = {}
        for entry in values:
            key,value = entry.split("=",1)
            # Try and load value as a JSON object. If that fails, treat it as a string.
            try:
                parsed_value = json.loads(value)
            except json.JSONDecodeError:
                parsed_value = value
            result[key] = parsed_value

        setattr(namespace, self.dest, result)