code: def zsymDecorator(odd):
      
      def wrapper(func):
          @wraps(func)
          def zsym_wrapper(*args,**kwargs):
              if args[0]._zsym:
                  out= func(args[0],args[1],numpy.fabs(args[2]),**kwargs)
              else:
                  out= func(*args,**kwargs)
              if odd and args[0]._zsym:
                  return sign(args[2])*out
              else:
                  return out
          return zsym_wrapper
      return wrapper
docs: Decorator to deal with zsym=True input; set odd=True if the function is an odd function of z (like zforce)