code: def load_data(self, key=None, **kwargs):
          
          self.store.open()
          if key:
              return pd.read_hdf(self.PATH_DATABASE, key, **kwargs)
          else:
              data_load = dict()
              for k in self.store.keys():
                  k = k.replace('/', '')
                  # **kwargs ej:= where=['index > 2009','index < 2010'],columns=['ordinal']
                  data_load[k] = pd.read_hdf(self.PATH_DATABASE, k, **kwargs)
              self.data = data_load
          self.store.close()
          self.integridad_data()
docs: Lee de disco la información y la devuelve
          :param key: