code: def datafile_from_hash(hash_, prefix, path):
          
          pattern = '%s_%s*.h*' % (prefix, hash_)
          datafiles = list(path.glob(pattern))
          if len(datafiles) == 0:
              raise NoMatchError('No matches for "%s"' % pattern)
          if len(datafiles) > 1:
              raise MultipleMatchesError('More than 1 match for "%s"' % pattern)
          return datafiles[0]
docs: Return pathlib.Path for a data-file with given hash and prefix.