Json loader

json_loader.py

import json


class JLoader(object):
    def __init__(required=None):
        self._required = required

    def _check_arguments(self, keys):
        keys = set(keys)
        if required:
            diff = set([req in keys for req in required]) - keys
            if diff:
                raise KeyError('Keys: {} missing from file'.format(diff))

    def load(self, filename):
        with open(filename, 'r') as fh:
            dic = json.load(fh)
        self._check_arguments(dic.keys())
        return dic