python装饰器的奇怪语法规范

Question

function definitions的语法规范：

funcdef        ::=  [decorators] "def" funcname "(" [parameter_list] ")" ["->" expression] ":" suite
decorators     ::=  decorator+
decorator      ::=  "@" dotted_name ["(" [parameter_list [","]] ")"] NEWLINE
dotted_name    ::=  identifier ("." identifier)*
parameter_list ::=  (defparameter ",")*
                    | "*" [parameter] ("," defparameter)* ["," "**" parameter]
                    | "**" parameter
                    | defparameter [","] )
parameter      ::=  identifier [":" expression]
defparameter   ::=  parameter ["=" expression]
funcname       ::=  identifier

似乎表明以下在语法上是有效的：

@some.dotted.name(*what : "is this")
def my_func(x):
    pass

但口译员不接受。我是误读了语法，还是语法不正确

Answer 1

在我看来像是个文档错误

是的

decorator      ::=  "@" dotted_name ["(" [argument_list [","]] ")"] NEWLINE

直到v3.2，当argument_list更改为parameter_list。这不可能是对的，尽管提交one-line patch的人显然不这么认为

未修改grammar itself。上面还写着：

decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE

既然是这样：

the full Python grammar, as it is read by the parser generator and used to parse Python source files

我想我们可以得出这样的结论：Python装饰器仍然具有我们所期望的语法