code: def dataframe(self, sids, head=0, tail=EPOCHS_MAX, datetime=True):
          
          if head is None:
              head = 0
          else:
              head = self._2epochs(head)
  
          if tail is None:
              tail = EPOCHS_MAX
          else:
              tail = self._2epochs(tail)
  
          series = [self.series(sid, head=head, tail=tail, datetime=False)
                    for sid in sids]
          df = pd.concat(series, axis=1)
          if datetime is True:
              df.index = pd.to_datetime(df.index, unit="s", utc=True)
          return df
docs: Create data frame
  
          Parameters
          ----------
          sids : list[str]
          head : int | pandas.Timestamp, optional
              Start of the interval
              default earliest available
          tail : int | pandas.Timestamp, optional
              End of the interval
              default max epoch
          datetime : bool
              convert index to datetime
              default True
  
          Returns
          -------
          pandas.DataFrame