Controlling assignation

[Xavier Décoret]

Bruno Desthuilliers a écrit :
> Xavier Décoret a écrit :
> (snip)
> 
>> What I wanted to do is something like this:
>>
>> def change(x,v):
>>     x = v
>>
>> class A(object):
>>     def __init__(self,v):
>>         self.x = v
>>
>> a = A(3)
>> print a.x  # displays 3
>> change(a.x,4)
>> print a.x  # still displays 3
>>
>>
>> It may seem weird, 
> 
> 
> It does
> 
>> but I ensure there is a reason for doing this. 
> 
> 
> I really wonder what it can be ???

It's the ability to develop the equivalent of GeoNext (and much more) in 
  Python with a very nice syntax.

> 
> You could achieve the same effect with:
> 
> class A( object):
>   def __init__(self, value):
>     self.value = value
> 
> a = A(3)
> a.value = 4
> a.value
> => 4
> 

Of course, and even simpler ;-)
print "4"

More seriously, try to do this with your simpler approach.

a = A(4)
b = A(lambda : a.x+5)
a.x = 2

print b.x # I want this to be 7, not 9


> And it's *much* more simple/readable/efficient.
> 
> Ever googled for "evolution of a programmer" ?-)
> 
> 
Not to brag, but I think I know what programming is.  Google for my 
name. C'est bien un commentaire de francais ca ;-)