[Python-ideas] make __closure__ writable

[Mark Shannon]

Tim Delaney wrote:
> On 26 March 2012 11:32, Victor Stinner <victor.stinner at gmail.com 
> <mailto:victor.stinner at gmail.com>> wrote:
> 
>     2012/3/16 Yury Selivanov <yselivanov.ml at gmail.com
>     <mailto:yselivanov.ml at gmail.com>>:
>      > Can we make the __closure__ attribute writeable?  Since __code__
>     already is, ...
> 
>     I never understood why __code__ is writable. What is the usecase of
>     modifying the code of an existing function?
> 
> 
> There are many things you can do with bytecode manipulation (whether you 
> should is another question). Among other things, I've used it for 
> optimisation (e.g. my optimised self.super recipe that probably isn't 
> actually available online anymore). Instrumentation of code is another 
> thing, although these days you're probably better off using a decorator.
> 
> There aren't a lot of real use cases, but if nothing else it can be a 
> lot of fun :)

You can do all of those things without changing the __code__ attribute.
Just create a new function instead.

Cheers,
Mark