code: def _pipeline_output(self, pipeline, chunks, name):
          
          today = normalize_date(self.get_datetime())
          try:
              data = self._pipeline_cache.get(name, today)
          except KeyError:
              # Calculate the next block.
              data, valid_until = self.run_pipeline(
                  pipeline, today, next(chunks),
              )
              self._pipeline_cache.set(name, data, valid_until)
  
          # Now that we have a cached result, try to return the data for today.
          try:
              return data.loc[today]
          except KeyError:
              # This happens if no assets passed the pipeline screen on a given
              # day.
              return pd.DataFrame(index=[], columns=data.columns)
docs: Internal implementation of `pipeline_output`.