new_contents: #!/usr/bin/env python
  # -* coding: utf-8 -*
  
  from chemharp import *
  import os
  
  FILENAME = "test-python.xyz"
  
  CONTENT = """4
  Written by Chemharp
  He 0 0 0
  He 0 0 0
  He 0 0 0
  He 0 0 0
  """
  
  if __name__ == "__main__":
      traj = Trajectory(FILENAME, "w")
  
      top = Topology()
      for _ in range(4):
          top.append(Atom("He"))
  
      frame = Frame(4)
      # TODO set positions
      frame.topology = top
      traj.write(frame)
      traj.close()
  
      with open(FILENAME) as f:
          assert(f.read() == CONTENT)
  
      os.remove(FILENAME)
  
subject: Write test in Python