import re


def parse_lonlat(string):
    """Return longitude and latitude from a string."""
    try:
        lon, lat = tuple(map(float, re.findall(r'[-+]?[0-9]*\.?[0-9]+', string)))
        return lon, lat
    except Exception as e:
        msg = '{}: Failed to parse longitude, latitude coordinates {}'.format(e, string)
        raise ValueError(msg)