def _unwrap_dict(dictionary, index_string):
    '''
    Accepts index in form of a string
    Returns final value
    Example: dictionary = {'a': {'b': {'c': 'foobar'}}}
             index_string = 'a,b,c'
             returns 'foobar'
    '''
    index = index_string.split(',')
    for k in index:
        dictionary = dictionary[k]
    return dictionary