code: def subsample(self, down_to=1, new_path=None):
          
          # Auto path #
          if new_path is None: subsampled = self.__class__(new_temp_path())
          elif isinstance(new_path, FASTA): subsampled = new_path
          else:                subsampled = self.__class__(new_path)
          # Check size #
          if down_to > len(self):
              message = "Can't subsample %s down to %i. Only down to %i."
              print Color.ylw + message % (self, down_to, len(self)) + Color.end
              self.copy(new_path)
              return
          # Do it #
          subsampled.create()
          for seq in isubsample(self, down_to): subsampled.add_seq(seq)
          subsampled.close()
          # Did it work #
          assert len(subsampled) == down_to
          return subsampled
docs: Pick a number of sequences from the file pseudo-randomly.