Converts a port number or multiple port numbers, as used in the Dockerfile ``EXPOSE`` command, to a tuple.

    :param: Port numbers, can be as integer, string, or a list/tuple of those.
    :type expose: int | unicode | str | list | tuple
    :return: A tuple, to be separated by spaces before inserting in a Dockerfile.
    :rtype: tuple

def format_expose(expose):
    """
    Converts a port number or multiple port numbers, as used in the Dockerfile ``EXPOSE`` command, to a tuple.

    :param: Port numbers, can be as integer, string, or a list/tuple of those.
    :type expose: int | unicode | str | list | tuple
    :return: A tuple, to be separated by spaces before inserting in a Dockerfile.
    :rtype: tuple
    """
    if isinstance(expose, six.string_types):
        return expose,
    elif isinstance(expose, collections.Iterable):
        return map(six.text_type, expose)
    return six.text_type(expose),