np array to xyz.py

def array_to_xyz(filename, array):
    """
    Append many frames to the same xyz file that ovito can read
    The file is overwritten everytime
    array: [frame_1, frame_2, ...]
    coordinate in one frame: (dimension, number_of_particles)
    """
    if '.xyz' == filename[-4:]:
        fname = filename
    else:
        fname = name + '.xyz'
    f = open(fname, 'w')
    f.close()
        
    for i, frame in enumerate(array):
        dim, num = frame.shape
        with open(fname, 'a') as f:
            np.savetxt(
                f, frame.T,
                delimiter='\t',
                fmt=['A\t%.8e'] + ['%.8e' for i in range(dim - 1)],
                comments='',
                header=f'{num}\nframe {i}'
            )