code: def get_age(Rec, sitekey, keybase, Ages, DefaultAge):
      
      site = Rec[sitekey]
      gotone = 0
      if len(Ages) > 0:
          for agerec in Ages:
              if agerec["er_site_name"] == site:
                  if "age" in list(agerec.keys()) and agerec["age"] != "":
                      Rec[keybase + "age"] = agerec["age"]
                      gotone = 1
                  if "age_unit" in list(agerec.keys()):
                      Rec[keybase + "age_unit"] = agerec["age_unit"]
                  if "age_sigma" in list(agerec.keys()):
                      Rec[keybase + "age_sigma"] = agerec["age_sigma"]
      if gotone == 0 and len(DefaultAge) > 1:
          sigma = 0.5 * (float(DefaultAge[1]) - float(DefaultAge[0]))
          age = float(DefaultAge[0]) + sigma
          Rec[keybase + "age"] = '%10.4e' % (age)
          Rec[keybase + "age_sigma"] = '%10.4e' % (sigma)
          Rec[keybase + "age_unit"] = DefaultAge[2]
      return Rec
docs: finds the age record for a given site