Decorator question

Wed Jan 26 21:37:57 EST 2011

On Jan 26, 6:17 pm, Chris <reilly.christop... at gmail.com> wrote:
> I have a class (A, for instance) that possesses a boolean (A.b, for
> instance) that is liable to change over an instance's lifetime.
>> Many of the methods of this class (A.foo, for instance) should not
> execute as long as this boolean is false, but should instead raise an
> exception.
>> Can I use a decorator to implement this functionality?  More exactly,
> could I define a function called 'checker' that accomplishes this:
>> def checker(f):
>     ...
>> class A():
>>     b = True
>>     @checker
>     def foo(self,...):
>         print 'in foo'
>> a = A()
> a.foo()
> a.b = False
> a.foo()
>> would result in:
>> 'in foo'
> Exception: ...
>> This exact solution isn't necessary, just something that doesn't
> require me to have the clunky:
>> def foo(self,...):
>     if self.b:
>         ...
>     else: raise Exception('b attribute must be true before executing
> this method')
>> in every method.
>> Thanks,
>> Chris

Sorry, discovered answer here:
http://stackoverflow.com/questions/2309124/get-class-in-python-decorator