code: def none_coalesce_handle(tokens):
      
      if len(tokens) == 1:
          return tokens[0]
      elif tokens[0].isalnum():
          return "({b} if {a} is None else {a})".format(
              a=tokens[0],
              b=none_coalesce_handle(tokens[1:]),
          )
      else:
          return "(lambda {x}: {b} if {x} is None else {x})({a})".format(
              x=none_coalesce_var,
              a=tokens[0],
              b=none_coalesce_handle(tokens[1:]),
          )
docs: Process the None-coalescing operator.