code: def column(table_name, column_name=None, cache=False, cache_scope=_CS_FOREVER):
      
      def decorator(func):
          if column_name:
              name = column_name
          else:
              name = func.__name__
          add_column(
              table_name, name, func, cache=cache, cache_scope=cache_scope)
          return func
      return decorator
docs: Decorates functions that return a Series.
  
      Decorator version of `add_column`. Series index must match
      the named table. Column name defaults to name of function.
  
      The function's argument names and keyword argument values
      will be matched to registered variables when the function
      needs to be evaluated by Orca.
      The argument name "iter_var" may be used to have the current
      iteration variable injected.
      The index of the returned Series must match the named table.