def convert2str(val):
    """Converts a value to a basic string."""
    if isinstance(val, list):
        if isinstance(val[0], list):
            # 2D list, delimit with ',' and ';'
            return '; '.join([', '.join([str(i) for i in j]) for j in val])
        else:
            # 1D list, delimit with ','
            return ', '.join([str(i) for i in val])
    else:
        # str() will handle ints, floats, bools and NoneType
        return str(val)