How to use the dictdiffer.DictDiffer function in dictdiffer

def setUp(self):
        a = {'a': 1, 'b': 1, 'c': 0}
        b = {'a': 1, 'b': 2, 'd': 0}
        self.d = DictDiffer(b, a)

def diff_dicts(d1, d2, d1_label='d1', d2_label='d2', print_unchanged=False):
    """
    Diff two dictionaries - prints changed, added and removed keys and the changed values. DOES NOT DO NESTED DICTS!

    :param d1: First dict - we compare this with d2
    :param d2: Second dict - we compare against this one
    :param d1_label: Will be used instead of "d1" in debugging output to make it more helpful.
    :param d2_label: Will be used instead of "d2" in debugging output to make it more helpful.
    :param print_unchanged: - should we print set of unchanged keys (can be long and useless). Default: False.
    :return: nothing, prints results to STDOUT
    """
    differ = dictdiffer.DictDiffer(d1, d2)
    print 'Added :: keys present in {d1} which are not in {d2}'.format(d1=d1_label, d2=d2_label)
    print differ.added()
    print
    print 'Removed :: keys present in {d2} which are not in {d1}'.format(d1=d1_label, d2=d2_label)
    print differ.removed()
    print
    print 'Changed :: keys which are the same in {d1} and {d2} but whose values are different'.format(d1=d1_label, d2=d2_label)
    print differ.changed()
    print

    if differ.changed():
        print 'Changed values :: the values of keys which have changed. Format is as follows:'
        print '  Key name:'
        print '    value in {d1}'.format(d1=d1_label)
        print '    value in {d2}'.format(d2=d2_label)
        print

def recurse(context, c, o):
        dd = dictdiffer.DictDiffer(c, o)
        changed = dd.changed()
        added = dd.added()

        for a in added:
            context[a] = c[a]

        for change in changed:
            sub = c[change]
            if isinstance(c[change], dict):
                context[change] = {}
                recurse(context[change], c[change], o[change])
            else:
                context[change] = sub