Compare hierarchical dict / list like structures

compare_json.py

def compare_json(first, second, keys=None):
    if first == second:
        return True

    if keys is None:
        keys = []

    def prefix(keys):
        return '[{}]'.format(']['.join(keys))

    # Used to keep track of whether we have already detected the difference (and reported
    # the error).
    same = True

    if isinstance(first, dict) and isinstance(second, dict):
        for key in set(list(first.keys()) + list(second.keys())):
            subkeys = keys + [key]
            if key not in first:
                print("Key '{}' not in first\n".format(prefix(subkeys)))
                same = False
                continue
            if key not in second:
                print("Key '{}' not in second\n".format(prefix(subkeys)))
                same = False
                continue

            if not compare_json(first[key], second[key], subkeys):
                same = False

    if isinstance(first, (list, tuple)) and isinstance(second, (list, tuple)):
        lfirst = len(first)
        lsecond = len(second)

        if lfirst > lsecond:
            print('items in first not in second{} {}\n'.format(
                prefix(keys),
                repr(first[lsecond:]),
            ))
            same = False
        if lsecond > lfirst:
            print('items in first not in second{} {}\n'.format(
                prefix(keys),
                repr(second[lfirst:]),
            ))
            same = False

        for (i, (f, s)) in enumerate(zip(first, second)):
            if not compare_json(f, s, keys + [str(i)]):
                same = False

    if same:
        # They can't be the same if we reach this point but we have failed to detect it so
        # assume that at least one object is not a list / dict and report them.
        print("First {0} is not equal to Second {0}\n".format(prefix(keys)))

    return False