How to use the dictdiffer._compat.string_types function in dictdiffer

def get_path(patch):
    """Return the path for a given dictdiffer.diff patch."""
    if patch[1] != '':
        keys = (patch[1].split('.') if isinstance(patch[1], string_types)
                else patch[1])
    else:
        keys = []
    keys = keys + [patch[2][0][0]] if patch[0] != 'change' else keys
    return tuple(keys)

def change(node, changes):
        dest = dot_lookup(destination, node, parent=True)
        if isinstance(node, string_types):
            last_node = node.split('.')[-1]
        else:
            last_node = node[-1]
        if isinstance(dest, LIST_TYPES):
            last_node = int(last_node)
        _, value = changes
        dest[last_node] = value

    if all(map(lambda x: isinstance(x, string_types), node)):
        return '.'.join(node)