from typing import Iterable


def encode_in_readname(readname: str, data: Iterable[str], sep: str=":") -> str:
    """
    Encode data in the read-name.
    :param readname: the name of a read
    :param data: a list of data to encode in the read name
    :param sep: the field separator in the read name, default is :
    :return: a new readname with the data encode
    """
    return readname + sep + sep.join([str(d) for d in data])