code: def from_file(cls, h5_file):
          
          return cls({
              country: HDF5DailyBarReader.from_file(h5_file, country)
              for country in h5_file.keys()
          })
docs: Construct from an h5py.File.
  
          Parameters
          ----------
          h5_file : h5py.File
              An HDF5 daily pricing file.