code: def pfLon(jd, lat, lon):
      
      sun = swe.sweObjectLon(const.SUN, jd)
      moon = swe.sweObjectLon(const.MOON, jd)
      asc = swe.sweHousesLon(jd, lat, lon,
                             const.HOUSES_DEFAULT)[1][0]
      
      if isDiurnal(jd, lat, lon):
          return angle.norm(asc + moon - sun)
      else:
          return angle.norm(asc + sun - moon)
docs: Returns the ecliptic longitude of Pars Fortuna.
      It considers diurnal or nocturnal conditions.