<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def nice_join(seq, sep=", ", conjunction="or"):
    ''' Join together sequences of strings into English-friendly phrases using
    a conjunction when appropriate.

    Args:
        seq (seq[str]) : a sequence of strings to nicely join

        sep (str, optional) : a sequence delimiter to use (default: ", ")

        conjunction (str or None, optional) : a conjunction to use for the last
            two items, or None to reproduce basic join behavior (default: "or")

    Returns:
        a joined string

    Examples:
        >>> nice_join(["a", "b", "c"])
        'a, b or c'

    '''
    seq = [str(x) for x in seq]

    if len(seq) <= 1 or conjunction is None:
        return sep.join(seq)
    else:
        return "%s %s %s" % (sep.join(seq[:-1]), conjunction, seq[-1])