code: def save_discrete_trajectory(filename, dtraj):
      r
      dtraj=np.asarray(dtraj)
      np.save(filename, dtraj)
docs: r"""Write discrete trajectory to binary file.
  
      The discrete trajectory is stored as ndarray of integers
      in numpy .npy format.
  
      Parameters
      ----------
      filename : str
          The filename of the discrete state trajectory file.
          The filename can either contain the full or the
          relative path to the file.
  
  
      dtraj : array-like
          Discrete state trajectory.