Carrying variables over from function to function

[Bruno Desthuilliers]

Ivan Shevanski a écrit :
> Alright heres my problem. . .Say I want to carry over a variable from 
> one function to another or even another run of the same function. Is 
> that possible? Heres a quick example of what I'm talking about.
> 
> def abc():
>    x = 1
>    y = x + 1
>    print y
> 
> def abcd():
>    y = x + 1
>    print y
> 
> abc()
> abcd()
> 
> the output would be:
> 
>>>> abc()
> 
> 2
> 
>>>> abcd()
> 
> Traceback (most recent call last):
>    File "(stdin)", line 1, in ?
>    File "(stdin)", line 2, in abcd
> NameError: global name 'x' is not defined
> 
>>>> 
> 
> 
> See, I want y in the second function to equal 4, carrying the x from the 
> first function over to the next.  Is there any way to do this?
> 

Actually, there are at least 3 ways to do it.

1/ Dirty solution:
------------------
x = 0
def abc():
   global x
   x = 1
   print x + 1

def abcd():
   global x
   print x + 1


2/ functional solution:
-----------------------
def make_funcs():
   x = 0
   def _abc():
     x = 1
     return x + 1
   def _abcd():
     return x + 1
   return _abc, _abcd

abc, abcd = make_funcs()
print abc()
print abcd()


3/ OO solution:
---------------
class Foo(object):
   def __init__(self):
     self._init_x()

   def _init_x(self):
     self._x = 1

   def abc(self):
     self._init_x()
     return self.abcd()

   def abcd(self):
     return self._x + 1

f = Foo()
print f.abc()
print f.abcd()


Now guess which are:
A/ the pythonic solution
B/ the worst possible solution
C/ the most arcane solution

!-)