manipulating class attributes from a decorator while the class is being defined

[Duncan Booth]

Wilbert Berendsen <wbsoft at xs4all.nl> wrote:

> Hi, is it possible to manipulate class attributes from within a
> decorator while the class is being defined?
> 
> I want to register methods with some additional values in a class
> attribute. But I can't get a decorator to change a class attribute
> while the class is still being defined. Something like:
> 
> class Parser(object):
>   
>   regexps = []
>   def reg(regexp):
>     def deco(func):
>       regexps.append((regexp, func))
>       return func
>     return deco
>   
>   @reg(r'".*"')
>   def quoted_string(self):
>     pass
> 
> How can I reach the class attribute `regexps' from within a decorator?
> 

Have you tried passing regexps into the decorator as a default argument?

  def reg(regexp, regexps=regexps):
    def deco(func):
      regexps.append((regexp, func))
      return func
    return deco