def get_namespaces_with_prefixes(namespaces):
    """ Get a dictionary of namespaces less namespaces that have no prefix

    Args:
        namespaces (:obj:`dict`): dictionary that maps prefixes of namespaces their URIs

    Returns:
        :obj:`dict`: dictionary that maps prefixes of namespaces their URIs
    """
    if None in namespaces:
        namespaces = dict(namespaces)
        namespaces.pop(None)
    return namespaces