import numbers


def _monomer_pattern_label(mp):
    """Return a string label for a MonomerPattern."""
    site_values = [str(x) for x in mp.site_conditions.values()
                            if x is not None
                            and not isinstance(x, list)
                            and not isinstance(x, tuple)
                            and not isinstance(x, numbers.Real)]
    return mp.monomer.name + ''.join(site_values)