text: # symshp: create a symmetry-expanded sphere about a selection
  
  # usage:
  #
  #    symexp name [,selection [,cutoff ]]
  
  from pymol import cmd as global_cmd
  
  def symsph(name, selection="sele", cutoff=20.0, self_cmd=global_cmd):
      cutoff = float(cutoff)
      prefix = selection+"_symarea_"
      tmp_obj = selection+"_tmp"
      if selection not in self_cmd.get_names("selections"):
          print(" error: '"+selection+"' is not defined.")
          return self_cmd.DEFAULT_ERROR
      if not self_cmd.count_atoms(selection):
          print(" error: '"+selection+"' contains no atoms.")
          return self_cmd.DEFAULT_ERROR
      obj_list = self_cmd.get_object_list(selection)
      if len(obj_list)!=1:
          print(script_name+" error: '"+selection+"' must only span one object.'")
          return self_cmd.DEFAULT_ERROR
      obj = obj_list[0]
      cmd.center(selection)
      cmd.pseudoatom(tmp_obj)
      cmd.delete(prefix+"*")
      cmd.symexp(prefix,obj,tmp_obj,cutoff,segi=1)
      cmd.create(name,"("+obj+" or "+prefix+"*) within %1.9f of %s"%(cutoff,tmp_obj))
      cmd.delete(tmp_obj)
      cmd.delete(prefix+"*")
      
  #symsph("sele",20)
  
  cmd.extend("symsph",symsph)
  
  
      
  
  