to pass self or not to pass self

[Rami Chowdhury]

On Monday 15 March 2010 10:42:41 TomF wrote:
> On 2010-03-15 09:39:50 -0700, lallous <elias.bachaalany at gmail.com> said:
> >     
> > Why in test1() when it uses the class variable func_tbl we still need
> > to pass self, but in test2() we don't ?
> > 
> > What is the difference between the reference in 'F' and 'func_tbl' ?
> 
> I recommend putting print statements into your code like this:
> 
>     def test1(self, n, arg):
>         print "In test1, I'm calling a %s" % self.func_tbl[n]
>         return self.func_tbl[n](self, arg)
> 
>     def test2(self):
>         f = self.f1
>         print "Now in test2, I'm calling a %s" % f
>         f(6)
> 
> 
> Bottom line: You're calling different things.  Your func_tbl is a dict
> of functions, not methods.
> 
> -Tom

To build on that a bit, note that in test2() you are doing:
> >         f = self.f1
> >         f(6)
> >         
> >         f = self.F
> >         # why passing self is not needed?
> >         f(87)

As I understand it, since you obtained the reference to 'f1' from 'self', you 
got it as a bound rather than an unbound method. So 'self' is automatically 
passed in as the first argument. 

----
Rami Chowdhury
"Given enough eyeballs, all bugs are shallow." -- Linus' Law
408-597-7068 (US) / 07875-841-046 (UK) / 01819-245544 (BD)