Given a tuple of tuples, generate a delimited string form.
    >>> results = [["a","b","c"],["d","e","f"],[1,2,3]]
    >>> print(str_delimited(results,delimiter=","))
    a,b,c
    d,e,f
    1,2,3

    Args:
        result: 2d sequence of arbitrary types.
        header: optional header

    Returns:
        Aligned string output in a table-like format.

def str_delimited(results, header=None, delimiter="\t"):
    """
    Given a tuple of tuples, generate a delimited string form.
    >>> results = [["a","b","c"],["d","e","f"],[1,2,3]]
    >>> print(str_delimited(results,delimiter=","))
    a,b,c
    d,e,f
    1,2,3

    Args:
        result: 2d sequence of arbitrary types.
        header: optional header

    Returns:
        Aligned string output in a table-like format.
    """
    returnstr = ""
    if header is not None:
        returnstr += delimiter.join(header) + "\n"
    return returnstr + "\n".join([delimiter.join([str(m) for m in result])
                                  for result in results])