code: def timeseries(self, dataframe=False):
          
  
          self.query.by_period()
          ts = super().timeseries(dataframe=dataframe)
          ts['value'] = ts['value'].apply(lambda x: float("%.2f" % x))
          return ts
docs: Get the date histogram aggregations.
  
          :param dataframe: if true, return a pandas.DataFrame object