def posList(value):
    """
    :param value:
        a string with the form `lon1 lat1 [depth1] ...  lonN latN [depthN]`
        without commas, where the depts are optional.
    :returns:
        a list of floats without other validations
    """
    values = value.split()
    num_values = len(values)
    if num_values % 3 and num_values % 2:
        raise ValueError('Wrong number: nor pairs not triplets: %s' % values)
    try:
        return list(map(float_, values))
    except Exception as exc:
        raise ValueError('Found a non-float in %s: %s' % (value, exc))
:param value:
        a string with the form `lon1 lat1 [depth1] ...  lonN latN [depthN]`
        without commas, where the depts are optional.
    :returns:
        a list of floats without other validations