On Sun, Oct 7, 2012 at 7:50 PM, Franck Ditter <fra...@ditter.org> wrote:
> def foo(self) :
> (a,b,c,d) = (self.a,self.b,self.c,self.d)
> ... big code with a,b,c,d ...
>
This strikes me as ripe for bug introduction. There's no problem if
you're just reading those values, and mutating them is equally fine,
but suddenly you need a different syntax for modifying instance
members.
def foo(self) :
(a,b,c,d) = (self.a,self.b,self.c,self.d)
e = a+b
c.append(1234)
d=self.d = 57 # Oops, mustn't forget to assign both!
Since Python lacks the extensive scoping rules of (say) C++, it's much
simpler and safer to be explicit about scope by adorning your instance
variable references with their "self." tags. There's a guarantee that
you can use "self.a" in any situation where you want to manipulate
that member, a guarantee that's not upheld by the local "a".
In theory, I suppose you could use a C-style preprocessor to help you.
class Foo(object):
#define asdf self.asdf
#define qwer self.qwer
def __init__(self,a,q):
asdf=a; qwer=q
def __repr__(self):
return "Foo(%s,%s)"%(asdf,qwer)
This is not, however, Pythonic code. But if you made some kind of
better declaration than #define, and used a preprocessor that
understood Python indentation rules and flushed its token list at the
end of the class definition, you could perhaps make this look
not-ugly. I still wouldn't recommend it, though.
ChrisA
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