Chris reilly.christopher at gmail.com
Wed Jan 26 21:37:57 EST 2011

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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

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