Update example

def post_force_callback(lmp, v):

  try:

    import os

    pid = os.getpid()

    pid_prefix = "[{}] ".format(pid)

    L = lammps(ptr=lmp)

    t = L.extract_global("ntimestep", 0)

    print("### POST_FORCE ###", t)

    print(pid_prefix, "### POST_FORCE ###", t)

    #mylist = L.get_neighlist(0)

    mylist = L.find_pair_neighlist("lj/cut", request=0)

    print(mylist)

    print(pid_prefix, mylist)

    nlocal = L.extract_global("nlocal", 0)

    nghost = L.extract_global("nghost", 0)

    ntypes = L.extract_global("ntypes", 0)

    f = L.numpy.extract_atom_darray("f", nlocal+nghost, dim=3)

    for iatom, numneigh, neighs in mylist:

      print("- {}".format(iatom), x[iatom], v[iatom], f[iatom], " : ",  numneigh, "Neighbors")

      print(pid_prefix, "- {}".format(iatom), x[iatom], v[iatom], f[iatom], " : ",  numneigh, "Neighbors")

      for jatom in neighs:

        if jatom < nlocal:

            print("    *  ", jatom, x[jatom], v[jatom], f[jatom])

            print(pid_prefix, "    *  ", jatom, x[jatom], v[jatom], f[jatom])

        else:

            print("    * [GHOST]", jatom, x[jatom], v[jatom], f[jatom])

            print(pid_prefix, "    * [GHOST]", jatom, x[jatom], v[jatom], f[jatom])

  except Exception as e:

    print(e)

"""

fix		1 all nve

fix     3 all python/invoke 1 post_force post_force_callback

fix     3 all python/invoke 50 post_force post_force_callback

#dump		id all atom 1 dump.melt

#dump_modify	3 pad 3

thermo		1

run		1

run		100