Decorator for Enforcing Argument Types

[Bruno Desthuilliers]

George Sakkis a écrit :
> John Machin wrote:
> 
>>Bruno Desthuilliers wrote:
>>
>>
>>><my humble opinion>
>>>Python is dynamic, and fighting against the language is IMHO a really
>>>bad idea. The only places where theres a real need for this kind of
>>>stuff are when dealing with the "outside world" (IOW : inputs and
>>>outputs). And then packages like formencode can do much more than mere
>>>type-checking
>>></my humble opinion>
>>
>>Agreed. The worst case I have seen:
>>
>>An elaborate decorator (similar to the OP's) laboriously checks arg
>>types. That's IMHO not "consenting adults" territory. But it gets a
>>whole lot worse when it's applied to a method whose body is like this:
>>
>>if isinstance(....
>>    action_for_type1(...
>># big snip
>>elif isinstance(...
>>    action_typeN( ...
>># no else statement
> 
> 
> Ouch.. someone must have skipped his/her OO class...
> 
Depends... I've sometimes had to write such kind of horrors - at least 
once: a wrapper class to ensure that all strings accessible directly *or 
indirectly* (via a dict, list, method call, whatever...) would be 
unicode strings...

But of course I didn't use decorators to type-check annything !-)