def join_rows(rows, joiner=' '):
    """
    Given a series of rows, return them as a single row where the inner edge cells are merged. By default joins with a single space character, but you can specify new-line, empty string, or anything else with the 'joiner' kwarg.
    """
    rows = list(rows)
    fixed_row = rows[0][:]

    for row in rows[1:]:
        if len(row) == 0:
            row = ['']
        
        fixed_row[-1] += "%s%s" % (joiner, row[0])
        fixed_row.extend(row[1:])

    return fixed_row